Catalina 34

General Activities => Main Message Board => Topic started by: Stu Jackson on June 07, 2008, 10:53:53 AM

Title: Battery Charger Evaluation by John Nixon (jmnpe) EXCELLENT
Post by: Stu Jackson on June 07, 2008, 10:53:53 AM
In a recent post John responded to questions about newer Xantrex battery chargers in a comprehensive and professional manner.  The high quality of his analysis suggested to me that it become a separate thread, rather than being buried in parts of a longer three page post, so here, in its entirety, is John's evaluation and report.  The original and additional "How to Charge Batteries" can be found can be found here:,4338.0.html (,4338.0.html)

Part 1

Hi everyone! Sorry to be so late for the party! Given the late hour, I'll probably have to do this in several sessions, but I'll try to answer all the questions eventually.

First, let me say that I am a mixed-bagger: I keep ( for the last 20-ish years) AC power on the boat 24/7 to keep the beer cold, and to keep the inside temperature of the boat reasonable with my wonderful 16,000 btu of reverse cycle air-conditioning. Down here in north central Texas, the boats never leave the water, and our temperatures can change about 100 degrees F from February to August. We don't have to worry about salt induced corrosion  up here, but I did the same thing while I had the Stamas 44 on the Texas gulf coast for 9 years by exercising reasonable preventative measures to prevent salt from causing potentially dangerous electrical hazards at the dock and on the boat. Having said that, the explanation for my veiled comment about not leaving the battery charger on 24/7 ( but not for the reason you might think ) is that I have no problem with AC power on all the time, but I have some technically sound reasons to not keep any kinds of deep cycle batteries on a charge 24/7.

All battery do not like having residual charge current flowing through their plates for extended periods of time. However, for our discussion here, I'll limit my comments in particular to deep cycle lead acid batteries. As Stu accurately quoted some of our direct correspondence, the problem created by continuous charge/residual current flow through lead acid batteries in positive grid corrosion. This is something that happens anyway during the charge process, but when the charge to float mode time ratio becomes mostly float mode, the grid corrosion continues to happen with no useful effect on the battery, so that the positive grid corrosion is highly accelerated. The grid corrosion produces increased internal impedance ( i.e. - reduced cranking capability ) and reduced deep cycle capacity from the loss of effectiveness of the positive plates. The relative reduction of capacity percentages I cited due to continuous charging versus cycle charging come from 2 primary sources: manufacturer's data, and my own empirical data from messing about with deep cycle batteries extensively since 2000. The primary manufacturer I have worked with is Concorde Battery, who manufactures not only the Lifeline AGM batteries, but also a complete line of aircraft and aerospace batteries in civil and military applications. The same family that owns Concorde Battery also owns Trojan Batteries, so the experience base there is pretty broad. Trojan was the premier manufacturer of submarine batteries during the diesel/electric submarine era. They are also still the leading manufacturer of golf cart batteries, among other batteries.

The stated 35 to 40% maximum reduction in useful life of a deep cycle lead acid battery due to continuous float charging was based upon Concorde's own testing and their experiences in field applications of their batteries in solar power applications ( the ultimate cycle charge environment ). My own customer experiences and the results of my own studies with the Lifeline batteries supports the stated range of useful life reduction with some reduced effect if the float voltage is temperature compensated and well regulated at the lower end of the allowable float voltage range. In the last several years, Concorde/Lifeline has reduced their recommended float voltage range from a nominal 13.4 volts to 13.2 volts, and this will further reduce the rate of positive grid deterioration in the float mode. In one of my own examples, the new AGM 4D batteries I installed on my Stamas 44 lived about 3.5 years in constant float mode at a temperature compensated 13.4 volt nominal. At the end of that time, the measured cranking power ( CCA ) and deep cycle capacity was reduced by about 20%. The next 1.5 years was spent using cycle charging, and the measured CCA and a-hr numbers were only about an additional 5% lower. I have to note that these examples are from premium grade AGM deep cycle batteries, and the results from a relatively inexpensive flooded battery would probably be significantly worse.

So, if 24/7 float charge is bad, what to do about 12 volt refrigeration ( i.e. - your Cold Machine )? The simple answer is to provide a suitable AC-to-DC power supply to run the fridge when you are at the dock, and then run it on the batteries when away from AC power. I have been doing this since 2002. There are a number of inexpensive and suitably reliable small switching power supplies out there that will do the task admirably.

One last quick comment: I like the TrueCharge + series because it has been an extremely reliable product with good features and performance at a fair price. I have never seen one fail at all in normal service in 8 years, and more importantly, never fail in a mode that produces an uncontrolled high output voltage across the batteries. This is in stark contrast to may of the other charges that were in use on boats over the same period of time. I think the TrueCharge II has excellent potential, but I want to see some in operation over time before I offer any additional opinion. I think the XC series is over-priced and touts primary features that offer little benefit in the real world.

This will have to be it for installment #1. I'll keep working down the list of questions and comments as quickly as I can.

 :clap :clap
Title: Re: Battery Charger Evaluation by Johh Nixon (jmnpe)
Post by: Stu Jackson on June 07, 2008, 10:54:14 AM
Part 2

Here we are again with installment #2, and the main topic here will be the AC-to-DC power supply usage with the Adler-Barbour Cold Machine.

First, a little background and history of the Adler-Barbour compressor. Prior to early 2000, all the compressors were fixed speed, brush commuted motors that had a very nasty current spike when the compressor started, but also were very electrically noisy while they were running. The installation manual for these units made a strong point of using big wire from the battery and the fact that you had to have a battery on the feed circuit to help "absorb" the current feedback of the motor back into the voltage source. Upon starting, the peak starting current was in the neighborhood of 17 amps for a couple of hundred milli-seconds. However, my discussions with the engineering folks back then ( pre-WAECO ) confirmed that with a reasonably "stiff" power supply ( i.e. - AC-to-DC power supply ) there was no reason that the compressor wouldn't be happy without a battery in the feed circuit. Of course, I had already tried it by then and knew that to be the case, but it made me feel better having them agree with me...... I used a 250w 12 volt nominal switching power supply with the output voltage set at about 13 volts, which meant that I had about 19 amps available. I used this from the end of 2002 with no problems on my Stamas 44, and the next owner is still using it. The power supply had a cooling fan that ran all the time, and the fan quit after about 3 years. However, since the run current of the compressor was only about 5 amps, the cooling fan wasn't really necessary anyway, and it wasn't an issue. However, the supplier of that power supply no longer carries or makes that power supply, so to duplicate what I did will require some adaptations ( at least at a reasonable price..... ).

For the post-2/2000 Cold Machines, the compressor was changed to a variable speed brushless motor in a slightly larger and more efficient compressor, the Danfoss BD50. The variable speed motor starts "softly", and the maximum start current is less than 10 amps. This means that a 150w power supply provides ample reserve to start the compressor, and really coasts along at the 4 to 5 amp run current. The motor also runs more electrically "quiet", which is a very good thing if you have other radio receivers on the boat. This is what I have now on Otra Vez.

For change-over from AC to DC power, I use a standard SPDT 30 amp automotive relay with the relay coil power by the AC power supply. The common terminal of the relay goes to the compressor, the NC contact of the relay goes to the DC feed circuit breaker, and the NO contact of the relay goes to the output of the AC power supply. If the AC power supply is powered up, the compressor runs from shore power; if not, it runs from the house battery bank. When I'm away from the boat with the charger turned off, I leave the fridge DC power turned off at the distribution panel: if shore power goes away, I don't want the batteries run down just to keep the beer and bottled water cold for a few days.......

The power supplies I have used on both the Stamas and the current C34 both came from The 150w power supply I use for the newer compressor is part number  16020 PS and costs $40.75. If you have an older compressor, you can use a pair of the same units in parallel after carefully setting the outputs to have equal voltages before tying the outputs together. If you want to pay more and have a better warranty, you can use part number 709-S150-12 from at $57.96 each. I should note that the cheap units from MPJA have worked without a hick-up for 5 years and counting being turned on 24/7.

When I have the schematic diagram of the power change-over relay scanned into a suitable format, I'll post it here as well.

For installment #3, I'll summarize my comparison of the TrueCharge+, TrueCharge2, and XC series of chargers. We'll of course ignore the fact that the TrueCharge2 is currently still marketing blue sky.......

Until later.

Part 2A

As a follow up to Installment #2, here is the schematic ( attachment ) for the AC-DC change-over relay and power supply wiring for the AC power supply addition to your Cold Machine. After looking over my original notes on the subject, I determined that the original 250w power supply that I used with my older Cold Machine compressor ( pre-2000 vintage ) was rated as 12v/17a. I also noted that I had adjusted the output voltage up to about 13.2 volts for maximum efficiency for the compressor. The 17a current rating is a continuous rating, and this power supply easily handled the substantial starting load surge of the older compressor.

Based upon this information, there are actually 2 better options for power supply selection for the pre-2000 compressors. If you don't mind configuring a pair of units for parallel operation, you can use a pair of 100w units from, part number PS1-100W-SF12 at $32.80 each. If you would rather have a single unit, use a 240W unit from, part number 137649 at $106.85. This unit has a 2 year warranty and a cooling fan that only runs on demand, which in this application will be almost never.

Craig, if you add the AC power adaption to your fridge, it can be cold all the time if you have shore power available at the dock  . I think I'll stay away from remote diesel heater starting............

(Fridge PS with Replay wiring PDF file attached to this post, see below)

Installment #3: Xantrex charger review and associated comments.

The actual comparison tabulation is attached as a pdf file. I tried only to list the areas that could be meaningful in normal usage. There are other shared features with small technical differences, but I judged them not worthy of much discussion. All of them have various protection features for either the charger or the batteries, so there wasn’t too much point in dissecting the small print.

If you scan across the product offerings, you will note that the Truecharge2 (when it ever is actually available…) is a poor substitute for the Truecharge+. If the offered price at WM holds, the Truecharge2-40 charger + BTS combo costs more than the equivalent price of it’s namesake. Not only that, it offers a significant feature loss with the elimination of the 2 stage charge protocol option ( more on that later ). The only advantage that the “2” offers over the “+” is being about 5 inches shorter in length and about a half inch shorter in height. If that is not an issue, the “+” wins hands down.

After careful reading of the product information for the XC series, I can see a few things to like compared to the “+”. The on board control/display panel insert is removable and can become a fully functional control / display panel, which I think is a nice improvement over the pretty dumb and way-too-big remote display-only panel offered with the “+”. The XC also retains the option of either 3 or 2 stage charge protocols, with the addition of an improved float mode which, although not well described, appears to have the ability to function in a pseudo-inactive float mode after spending a reasonable amount of time in the active float mode. For the record, a full charge can only be achieved by either an active float mode charge ( constant regulated voltage at less than bulk ) for many hours, or at the absorption voltage for an extended period of time, or a charge at the absorption voltage until the actual battery charge current gets below a relatively low threshold. If the pseudo-inactive float mode works as implied, the 2 stage charge protocol becomes less important except for a few limited number of specialty cases.

The big advertising hype for the XC focuses on the ability to mix battery chemistries between the 3 banks. While this sounds good, in most practical applications is has little importance. A mix of flooded cells and AGM batteries can be done using only the AGM charge parameters. Not many people use true gel cells any more, and if they do, it’s usually all gel cells because of the problems associates with single source charging from the main engine alternator. While it’s true that the multiplexed or sequential charging of the 3 banks means that each battery will be presented with an optimal charge step series based upon the charge state of the particular battery bank, the down side of this scheme is that as you sit on your boat at night with the cabin lights on, there will be periodic and noticeable light intensity changes as your house bank goes from being on charge to off charge. In this scheme, only one battery bank at a time is actually under charge. [ Jon, can you comment on how noticeable this is in the real world?? ] Since on my boat my primary battery charger will be the Prosine 2.0 inverter/charger, I am pretty committed to single source charging at the dock or underway, and the equivalent of multi-source charging for my single house bank and dedicated starting battery ( all AGM ) is not a big issue.

If you spend long periods of time away from your boat, and you don’t have “shore power phobia” , then the XC series offers an optimized solution to keeping all your batteries well cared for in your absence with the sequential/multiplexed charging and the pseudo-inactive float mode.

If you are only away from your boat for a less than a month at a time, either the “+” or the XC versions can keep your batteries and your boat safe in our absence. You can accomplish 90% of what the XC can do in this situation with the “+” by placing it in the 2 stage mode after you have fully charged your batteries before your departure. Any of the Xantrex chargers with the 2 stage mode available will automatically come out of the inactive state and initialize a new 2 stage recharge if any battery falls below 12.5 volts for more than 15 minutes. In addition, it will automatically initialize a new charge cycle every 21 days from the last recharge cycle, or upon a new application of AC power to the charger. Those of you who worry about your Mother Of All Bilge Pumps running for hours at a time in your absence can rest easy as long as you have shore power available…….

For those you still using flooded cells, the automatic full recharge cycle every 21 days is especially important to you if your are away from you boat for significant lengths of time. Flooded cells have one not well recognized problem associated with sitting with no charge or on a float charge for long periods of time: acid stratification. What this means is that when a flooded cell sits still for long periods of time, the acid separates into different levels within the cell based upon the specific gravity of the acid. The portion of the acid that has the highest specific gravity settles to the bottom of the cell, with decreasingly lighter acid in layers above the denser acid. If you recall basic lead acid battery chemistry, low specific gravity is associated with lower charge levels, and higher specific gravity ( within certain limits ) with higher states of charge. Once this happens, the average state of charge of the battery decreases because most of the plates are in contact with a non-optimal acid mix. This can produce a significant loss of usable capacity. The good news is that it can be easily corrected by bringing the cell voltage well above the gassing voltage ( i.e. – to the absorption voltage ) and producing lots of bubbles: the flow of the bubbles up through the cell plates causes the acid to remix and restore a homogeneous specific gravity throughout the cell. This action also replaces charge lost through internal self-discharge of the battery ( only when left off charge: it doesn’t occur on float charge ), which with flooded cells can be as high as 20 to 30% of capacity per month. To make matters, the lead sulfate which forms because of self-discharge turns in the crystalline form more quickly than that which results from heavier discharge, and the crystalline form does not readily convert back into lead dioxide during normal recharging. Lead sulfate will turn into the crystalline form in about 45 to 60 days. Once your battery has lead sulfate in crystalline form, your battery has what will usually become a permanent capacity loss. This is what having your battery “all sulfated up” means. Most flooded cells need to be completely recharged every 30 to 45 days to avoid permanent sulfation.

OK: time for the BOTTOM LINE.

Truecharge 40+: Old but very good. Best feature set per amp of charge capacity. Can deliver first rate battery care in probably 90% of all applications. Has an exceptional field reliability history. Probably will get scarce once the Truecharge2 is available in large numbers. For now, Practical Sailor John gives it a “Best Buy” rating among the Xantrex selections.

Truecharge2-40: Newer than new ( not available currently ), “cute” with it’s modern look and smaller size, and capable of handling most normal applications. Lack of 2 stage charge protocol makes it less able to deal with unique situations. It will likely be reliable after the bugs are worked out of it ( and there will be some…. ). I doubt that the small current steps between models will be maintained once the product is out in the real world: too many production and inventory variants, and no justification technically for less than about 2:1 steps in charging current between models.  I would buy a “+” now rather than wait on this one to become available.

XC3012/XC5012: I wanted to not like this series based upon price and what I initially considered to be some gimmicky features. However, after careful study, I have to revise my opinion. Yes, it costs more per amp than a near equivalent “+” unit, but it does have some features that offer the possibility of longer battery life in a more automatic, transparent manner than other Xantrex or other brand offerings. Also, the fixed/remote control/display panel included as part of the basic package is a plus in some applications; if you already have a battery monitor system that can tell you all you want to know about your batteries ( and why wouldn’t you??? ), the remote display is not a big deal.  If the pseudo-inactive float mode works as indicated, that is a big factor in achieving true “plug-it-in-and-walk-away” battery care that has been unavailable in the consumer market up to now. Even though I need yet another battery charger like another hole in my head, I’m probably going to buy one just to put it through it’s paces and see if it can realize the potential I think it may have. I won’t say that I think you should go buy one, because I generally only do that based upon positive personal experience. You can buy one and experiment with me, or wait for my update in 6 months or so.

Well, I still have some battery and charging things on my list to pontificate about, but that will have to wait for Installment #4.

Hope this is useful.

(Comparison Table attached, see below)

Part 3A

From Jon Scneider:  Regarding the light intensity change due to charging on/off input, I have not noticed this yet.  I will be aboard tonight at dock, so I will check, but the only on/off cycling I will experience is between low input in float mode to zero-input in float, because my starter bank is charged via a Duo Charge, so I'm not sure I'd ever experience the change you're forecasting (i.e., the house bank is always the charge target).  I can, however, report that the "pseudo inactive float mode" does indeed work as advertised.  When I return to the boat after being away during the week, the charger reads 0 amps charging.  It stays that way while I'm using minor amounts of electricity (stereo, occasional water pump, etc.)  For me, the combination of this no-fuss approach, along with the battery temp sensor (one supplied), and the digital read-out are worth the price.  If I ever get an electric windlass, I may also use it to directly charge what will surely be a separate AGM battery (versus my flooded house bank).  That said, I thought I would do the same with my current AGM starter battery, but I went with the Duo Charge method instead, and I may do that with a dedicated windlass battery as well. 

Thanks again for doing this.  It's truly the most superb and educational product comparison I've ever read.

Back to John: 

You are correct about the lack of any "flickering" if you only have one battery connected to the XC. Under those conditions it would have "disqualified" the other 2 banks and would skip them in the sequential bank charge cycle, leaving only 1 battery in the "loop". You would never see any intensity change for all practical purposes under those conditions.

Thanks for the info.


Title: Re: Battery Charger Evaluation by Johh Nixon (jmnpe)
Post by: Stu Jackson on June 07, 2008, 10:55:27 AM
Comparison table PDF - click on the file to open or save
Title: Re: Battery Charger Evaluation by John Nixon (jmnpe)
Post by: Michael on June 17, 2008, 11:03:47 AM
We bought and installed a Xantrex XC3012 battery charger last week about the same time as John Nixon's review appeared here.  Fortunately, John seemed moderately favourable to this Xantrex offering.

However, only after doing the installation, talking "battery talk" with a friend who designs and builds DC power supplies, and re-reading John's review were we able to begin to appreciate how much John has put into that review.  It is worth reading and re-reading before making a decision on what battery charger to buy.

As I am incapable of speaking to the technical issues, this post will restrict itself to some practical aspects of dealing with the XC3012 in the context of a 1997 Catalina 34 where the battery charger is located in the galley sink cupboard beneath the built-in garbage can.

As John's review makes clear, the XC3012 comes with a small detachable control/display panel.  The detachable character of this panel is particularly useful in our application because it would be awkward to open the cupboard doors beneath the galley sink and stoop down to look at the panel beneath the built-in garbage can each time you wanted to see battery charging information.  Far better to have the panel where it will catch your attention.

For us Catalina 34 owners, it is also a good thing that the control/display panel is detachable because the height of the XC3012 with the panel in place in its plastic housing atop the main body of the XC3012 unit would make it well nigh impossible to place the XC3012 beneath the built-in garbage can.

As it is, the plastic housing for the control/display panel atop the XC3012 becomes (we think) redundant once you decide to mount the panel remotely.   Removing the plastic housing shaves a few inches off the height of the XC3012, with the result that the XC3012 unit fits quite nicely immediately beneath the built-in garbage can.  But don't be complacent about the height.  Locate the XC3012 as high as you can beneath the garbage can to give you working room below the charger, where you will need the room to get at the terminals, control connections, and AC connections.

In addition to housing the removable control/display panel, the plastic housing might serve some purpose in protecting the ventilation at the top of the XC3012 from water.  But given where we located the battery charger (beneath the shelf that supports the garbage can) we didn't think sacrificing the plastic housing was too risky from this point of view.

The plastic housing is secured to the "roof" of the XC3012 by four screws.  To get at these screws, you need to open up the XC3012, but even then it is only possible to get at the heads of two of the screws.  (This plastic housing -- like the plastic shell that goes over the front of the XC3012 that we also discarded - looks like something of an afterthought by Xantrex.)  We unscrewed the two screws whose heads we could get at then resorted to cutting the other two screws with a hacksaw where they emerged from the XC3012 main box and entered posts in the plastic housing.  We fished the screw heads out of the main box and threw away the plastic housing.  (Did we also lose any chance of making warranty claims?)

The new XC3012 is larger than the old Alltech Flyback 20-3 that it replaced on Hali and therefore it needed a bigger backing plate.  We glassed 1/2" plywood beneath the garbage can to enlarge the old backing plate.  With a coat of white bilgecoat over the new fiberglass, the backing plate now looks almost like part of the original construction.

Where to locate the control/display panel remotely was an issue.  The "telephone wire" that connects the control/display panel to the XC3012 is short, so placing the panel any distance from the battery charger involves getting a new telephone wire with connectors or getting an extension.  The good thing is that these four-wire connectors and telephone wires are universally available.

We first considered installing the control/display panel about calf height at the port side of the salon table aft settee, just next to our newly installed battery compartment ventilator.  (For discussion of installing a battery compartment vent, see Ron Hill's reply #33 and Jon Schneider's reply #34 at,4313.30.html.) There (on the outside of the settee battery compartment) the control/display panel would be readable by anyone sitting at the chart table, but probably only if you formed the conscious intention to read it and went looking for it.  This location on the outside of the settee battery compartment would have had the advantage of a very short control cable run from the battery charger. In fact, the original control/display panel cable would probably have sufficed.  But we finally decided that that location was not one where most people would expect to look for an instrument and not one where reading the control/display panel could happen routinely and unintentionally as we wanted, so we cut the control/display panel into the white wall beneath the electrical panel above the chart table where people can see it easily at any time.  We fished the control/display panel's four-wire control cable up behind the electrical panel and there added an extension cable to the battery charger.

Following Stu Jackson's advice (see reply #8 at,973.0.html), we recently decided to treat our two 4D house batteries as one bank when discharging from them.  To do this, we now use the "Both" switch all the time when operating under battery power.  However, as the XC3012 can charge, and monitor the charging of, three batteries (or three battery banks), it seemed a waste to treat both house batteries as one bank when charging them.  Accordingly, we set up the new charger so that it charges and monitors each of the house batteries separately. (We think that by charging each house battery separately we get more appropriate charging of each battery and specific information --from the control/display panel--about the condition of each battery.)

The Xantrex XC3012 comes with only one temperature sensor but with a capacity to handle three temperature sensors.  Xantrex recommends the use of a temperature sensor with each battery or battery bank that is separately charged.  Apparently the charger assumes a default temperature when there is no temperature sensor but achieves better charging when a temperature sensor provides actual battery temperature data to the charger.  Since in our installation we are charging each house battery separately, we bought a second temperature sensor.

To do the installation work, you will need to remove the "shelf" beneath the galley sink.

We found there was just sufficient room beneath the new charger to install a three gang terminal bus that is needed to connect the AC power feed to the battery charger's input pigtails.

The XC3012 has three positive and one common negative terminals.  You will want rubber terminal boots on the battery wires and over each of these terminals.  We haven't found a good place to get these but fortunately there were already good ones on the two positive battery wires.  The Xantrex-supplied terminal boots don't seem perfectly suited for the task but we used one of them on the common negative terminal.  Making the terminal connections in the limited space beneath the sink is a challenge but do-able.  (As mentioned previously, remember to situate the charger as high up beneath the built-in garbage can as possible.)

Clicking the "telephone connectors" of the temperature sensors and remote charger monitor into place on the base of the XC3012 is relatively easy but it is finnicky work to get them out again.  When trying to disconnect them, I was cursing and asking myself whether Xantrex engineers every do usability testing.  Don't click these connections into place until you are sure you won't likely have to remove them any time soon.

We haven't connected our independent starter battery to the XC3012 and haven't decided whether we will.  Hali's starter battery is used little -- since we solved a hard starting problem with huge help from this board a year ago (see,3347.0.html), Hali has started first time every time -- and is charged every time the engine runs.  But there is a third positive terminal on the XC3012 to which the starting battery (or perhaps an AGM battery for the windlass as Jon Schneider is contemplating) could be connected to. 

We have set the XC3012 to three-stage charging.  So far, it seems to run like a charm.  We haven't had enough experience with the system yet to know whether it will go into the pseudo-inactive float mode that John Nixon mentions in his review.

For the next few weeks anyway, we are likely to be "pluggers", that is, leaving Hali plugged into shore power when we are away from her, and "chargers", that is, leaving the new battery charger turned on while we are away from Hali.

We had run Hali's house bank down a bit in the days when we were swapping out the old Flyback 20-3 and installing the new XC3012.  After the XC3012 was installed and we were still on the boat, we saw the system bulk charging and absorb charging but never getting to float charging.  We saw a surprising 15.7 volts of charging at one point...and are still not sure what was going on.  A few days later, we took Hali out and on returning to the dock and plugging the system in, the charger very quickly was in float charge mode.  So it seems to have brought the batteries back to full charge.

Given that Hali has all lead acid batteries and her house batteries could be set up as one bank and her starting battery does not need to be charged from the AC-DC system, we could have purchased the Xantrex TrueCharge+40 and probably been happy with it.  However, the price difference between the Xantrex XC3012 and the TrueCharge+40 was so small here in Vancouver, that we opted for the newer XC3012.

Title: Re: Battery Charger Evaluation by John Nixon (jmnpe)
Post by: Stu Jackson on November 10, 2008, 09:41:36 AM
Continuing the Saga  (This is from here:

Here are few random comments on various topics emerging in this discussion, in no particular order.

Xantrex Echo Charge Function If you are using the built-in function contained in the larger Freedom Series inverter/chargers, be advised that you do not want to use the Echo Charge function with any low internal discharge batteries: i.e. - any form of AGM or Gel battery technologies. The way the Echo output(s) receive their power internally in the Freedom unit causes high voltage spikes to propagate through the Echo output and can result in float voltages appearing across connected low loss batteries up to 16 volts. This will result in rapid degradation of the positive plates in the battery and seriously reduce the useful life of the batteries. I haven't specifically looked at the stand-alone Echo charge module in detail, but I have seen the same problems appear with them when used with a few older chargers and some alternators that had "dirty" outputs.

Link 10 Replacement The old Link 10 has been directly replaced by the new Link LITE, and with one or 2 features unavailable in the basic Link 10. Of particular interest, the Link LITE provides for the display of a second battery voltage on the internal display much like the Link 1000 provided. The accuracy of the Link LITE is comparable to the original Link 10, and I think retails for a little less than the Link 10.
The Link PRO has all the features of the LITE but at higher internal accuracy for voltage and current measurements, and therefore all computed charging parameters are also more accurate. The PRO also offers a few features not available on the LITE, and the retail price is about 15 to 20% higher than the PRO depending where you buy it.

Truecharge2 I noticed that Xantrex has now dropped the ridiculous idea of having this charger available in 7 different output current levels. It is now produced in either 20 or 40 amps like it's predecessor. If you are using flooded cells, you will definitely be using the equalize function, and without the optional remote panel you will only be able to activate the equalize function from the control panel built into the charger, which means you will have to provide for physical access to that part of the charger unit. Unlike the remote panel option for the Truecharge+ series ( which was almost worthless ), the remote panel for the Truecharge2 will let you fully utilize/program any features available from the charger.

Microwave Ovens and Psuedo-Sine Wave Inverters  With a large fully charged battery bank, a non-smart "psuedo-sine wave" ( i.e. bastardized square wave ) inverter will sort of work a microwave, but always at reduced power output.  I have used one that way, and it was better than heating up the cabin in the summer with the regular stove or oven. As the battery voltage reduces, however, the microwave power starts to drop in a hurry and quickly becomes almost useless.
If you want to use the microwave a lot and effectively, you will have to go with a smart true sine wave inverter that will allow the microwave to maintain it's normal peak power output over a larger battery output voltage level range. As an added bonus, the microwave and some fans and power tools won't "growl" at you as the battery voltage level drops.....

Xantrex XC Series Chargers In my on-going evaluation of this product, I have discovered some disturbing characteristics when used with low internal loss batteries ( AGM for sure, and maybe Gel ) that I have discussed with Xantrex personnel and am still awaiting their response to my disclosures and questions. I'll update my previous product review on Xantrex chargers once I have received a response from Xantrex. For now, I will caution everyone to only use the XC Series chargers with flooded cell batteries.


C34 Otra Vez
1988 wing keel
Hull 728
Title: Re: Battery Charger Evaluation by John Nixon (jmnpe)
Post by: Stu Jackson on February 09, 2009, 03:34:18 PM
Added by John to a recent post (,4623.0.html):

One thing you need to know about the remote location option of the panel in the XC series charger is that while it can be removed from the main unit, there is no mounting means provided for it except for some rather permanent adhesive backed tape already in place around the periphery of the panel. If you ever want to be able to remove it from a mounting location, you will have to make a backing plate with a cutout to permanently mount the remote panel onto, and then mount the backing plate + remote panel assembly with screws in the corners. Not a very well thought out design detail in my opinion. The lip around the panel is relatively small, and drilling mounting holes in it could result in warranty issues in the future.

Also, as I noted previously, the XC series chargers for now(?) should only be used with flooded batteries because of over-voltage issues in the float mode with AGM batteries.
Title: Re: Battery Charger Evaluation by John Nixon (jmnpe) EXCELLENT
Post by: Stu Jackson on August 30, 2009, 03:12:37 PM
Added to a recent discussion about battery chargers, ProMariner & Fire Safety Hazard, here:,5179.0.html

Plugging In or Staying Unplugged, how it affects not only your fridge but your charger and batteries.  See the link to read the discussion that preceded this post

My professional experience with the Truecharge+ series ( the old yellow one ) has been very positive. They are still available online at attractive prices, and they will do a good job. The only "oops" with them was early in their production ( years ago ), they produced a whole bunch of them with the cooling fans wired backwards so that they were trying to push air through the unit instead of pull air through the unit, and this resulted in rapid failures. Other than that, they have been very good.

I have a new Truechage2 40 amp unit that I will fully evaluate and provide an update to my previous Battery Charger product review once Xantrex has the much-delayed remote panel available sometime next month. However, based upon the specs and limited testing, it appears that the Truecharge2 series will be generally very good, with possibly a few quirks that might earn it a low-level "WTF" comment.

Keeping you fridge running with the battery charger ON all the time will not "exercise" a smart battery charger like the Truecharge+ or Truecharge2 series of chargers, at least once the charger goes into the float mode. Once in the float mode, the Xantrex Truecharge_ series chargers will only initiate a full recharge sequence if the load causes the battery voltage to drop below about 12.5 volts for several minutes, OR once every 21 days. The low voltage re-trigger won't happen until the total load current significantly exceeds the rated capacity of the charger, which in the case of the Truecharge_ series will be either 20 or 40 amps. This won't happen with any of the small sealed compressor based systems that most of us have on our C34s.

The flip side of the argument is that your batteries will thank you if you don't leave them on a float charge for months and years at a time since this promotes positive grid corrosion ( i.e. - accelerated deterioration ) of your lead acid batteries. The alternative is to provide an AC powered DC power supply for just your 12v refrigeration system for when you are at the dock, and then use the battery charger to cycle charge your batteries when they actually need it. If you do a search of past postings, you will find the discussion I posted on how to do this, including where to get suitable parts. (see earlier posts right here in this topic) One of the Catalina owners even turned it into an article in the Technical Pullout section of the Mainsheet magazine about a year ago.
Title: Re: Battery Charger Evaluation by John Nixon (jmnpe) EXCELLENT
Post by: Andrew Harvey on November 20, 2009, 09:05:33 AM
Just an aside on the Xantrex chargers.

The first one I bought ( yellow ) did not work at all and the replacement died after about 6 months due to fan failure, likely from what was just described.
Customer service was terrible so I switched to Charles 30A that works flawlessly.

Title: Re: Battery Charger Evaluation by John Nixon (jmnpe) EXCELLENT
Post by: Stu Jackson on July 07, 2010, 07:06:20 PM
Interesting discussion at the C36 Message Board, discusses charging rates of AGMs and Iota chargers:

As mentioned many times, we suggest you check out the C36 Board, too, since they have many parallel discussions of the same systems we have on our boats, and many of their owners contribute here.
Title: Re: Battery Charger Evaluation by John Nixon (jmnpe) EXCELLENT
Post by: Jimlad on October 10, 2010, 02:50:01 AM
Where would the forum recommend locating a new battery charger? Any preferred locations?
Title: Re: Battery Charger Evaluation by John Nixon (jmnpe) EXCELLENT
Post by: Stu Jackson on October 10, 2010, 10:50:50 AM
Dave, a lot depends on where your old one was located.  Many Mark iI owners have put new ones under the trash bin.  They do fit there, even though it may not be apparent.  Do a search on "chargers" and I know you'll be able to find those posts.  Some have pictures.  Try the wiki, too, I forget if maybe there's some of those articles there also.
Title: Re: Battery Charger Evaluation by John Nixon (jmnpe) EXCELLENT
Post by: jmnpe on October 10, 2010, 11:14:37 AM
HI Dave,

The only hard rules for battery charger location are that it be a dry area ( unless you have a specifically "waterproof" charger, which is generally not the case for the ones we would normally consider ) and that it has reasonable ventilation for cooling. After that, there are not many locations that can't be made acceptable with money and/or effort. Also, by "dry" I mean not just dry normally, but also dry when something simple goes wrong, like a bilge pump system failure. Below the floor is a really bad place, and even at floor level is risky. Higher is better.

The second level requirements are preferred characteristics: reasonable proximity to the batteries, availability of AC power, and physical access to the charger unit if it doesn't have a remote control/display panel.

1. Depending upon the charging current capability of the charger, the distance from the charger to the batteries becomes an economic issue in that larger wire costs more than smaller wire. Forget the normal 3% voltage drop standard normally applied to electronics: a 3% drop in effective charge voltage in a 12 volt system is very significant in terms of charger efficiency and recharge time. I normally try to limit the maximum voltage drop in battery charger circuits to about 1% total at maximum possible charger current. If you have a multi-bank charger, this means that each output circuit would normally need the same size wire. If you have a dedicated starting bank that you generally never use for anything else, then you can likely get away with smaller wiring to that bank than the house bank, but you still need to have wire large enough that even the starter bank circuit can safely handle the maximum charger output current. I don't however recommend this. Remember, too, that the resistance/voltage drop of the charging circuit is based upon the entire length of the circuit loop: from the positive output terminal back to the Ground terminal of the charger. I have had limited exposure to the Mk II versions, but prior versions came from the factory with charger output circuit cables that were only minimally acceptable for the stock minimal chargers. Remember that when you are going to replace or upgrade the charger. I suspect that the early, if not all, Mk II versions share that problem.

2. The availability of AC power for the charger is generally not as much of an economic issue as it is an effort issue. On the Catalina 34 of all flavors, you can generally get from the AC distribution panel to almost anywhere on the boat with enough effort and patience. There is still the issue of appropriately sized wire. I like to see no more than a 10% voltage drop for the AC feed at maximum rated current, and generally try to keep is less that 4 or 5%. Older chargers will be effected more by low AC voltage than the newer smart chargers.

3. Physical access to the charger is important for 2 primary reasons: removal/replacement for service ( it will happen one day... ), and access to controls on the charger. If you have a newer smart charger, there will be setup required for use with your batteries. If you are using flooded cells, you will need to be able to access the controls to perform an Equalization cycle charge periodically on your batteries. Some, if not most, of the current new generation of chargers are offered with remote control/display panels that will allow you to monitor operation and perform any operational setup available from the remote panel. If this is the case, then your life is simpler and you have to be concerned only with maintenance access.

Although I haven't had time to update my Charger Review, my current "pick of the litter" for new chargers is the Truecharge2 series for most stand alone charger applications in boats of our size. This is true for all brands of chargers that are currently available based upon my experience with many other brands.



Title: Re: Battery Charger Evaluation by John Nixon (jmnpe) EXCELLENT
Post by: Jimlad on October 11, 2010, 01:49:38 AM
brilliant - what a great forum and its contributors
thanks guys
Title: Re: Battery Charger Evaluation by John Nixon (jmnpe)
Post by: xuwenli200888 on November 21, 2010, 06:53:05 PM
The stated 35 to 40% maximum reduction in useful life of a deep cycle lead acid battery due to continuous float charging was based upon Concorde's own testing and their experiences in field applications of their batteries in solar power applications ( the ultimate cycle charge environment ). My own customer experiences and the results of my own studies with the Lifeline batteries supports the stated range of useful life reduction with some reduced effect if the float voltage is temperature compensated and well regulated at the lower end of the allowable float voltage range. In the last several years,moncler ski ( Concorde/Lifeline has reduced their recommended float voltage range from a nominal 13.4 volts to 13.2 volts, and this will further reduce the rate of positive grid deterioration in the float mode. In one of my own examples, the new AGM 4D batteries I installed on my Stamas 44 lived about 3.5 years in constant float mode at a temperature compensated 13.4 volt nominal. At the end of that time, the measured cranking power ( CCA ) and deep cycle capacity was reduced by about 20%. The next 1.5 years was spent using cycle charging, and the measured CCA and a-hr numbers were only about an additional 5% lower. I have to note that these examples are from premium grade AGM deep cycle batteries, and the results from a relatively inexpensive flooded battery would probably be significantly worse.
Title: Re: Battery Charger Evaluation by John Nixon (jmnpe) EXCELLENT
Post by: Stu Jackson on May 09, 2012, 12:29:11 PM
Additional battery charger info for the newer Xantrex charger can be found here:,6926.0.html

Thanks, Michael and John.
Title: Re: Battery Charger Evaluation by John Nixon (jmnpe) EXCELLENT
Post by: Stu Jackson on June 10, 2012, 06:28:52 AM
From Maine Sail:
Title: Re: Battery Charger Evaluation by John Nixon (jmnpe) EXCELLENT
Post by: jmnpe on June 11, 2012, 10:30:12 AM
An excellent article by Maine Sail! Thanks, Maine Sail.


Title: Re: Battery Charger Evaluation by John Nixon (jmnpe) EXCELLENT
Post by: Stu Jackson on December 09, 2013, 09:49:50 AM
New generation of chargers are now available.

The "Electrical 101" Topic includes this:

Wiring a new charger From Maine Sail: (

corrected link 12/10/13 - Stu
Title: Re: Battery Charger Evaluation by John Nixon (jmnpe) EXCELLENT
Post by: Stu Jackson on April 24, 2016, 08:24:42 AM
John updated this in a Tech Note
Title: Re: Battery Charger Evaluation by John Nixon (jmnpe) EXCELLENT
Post by: jmnpe on April 25, 2016, 07:19:02 AM
Hi Stu,

Thanks for adding the update link. Glad you have my back :)