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.
John
