Trucharge 20+ Questions

[pjcomeau]

The installation guide for the Xantrex Truecharge 20+ highly recommends the use of a DC circuit breaker, a "fused disconnect", or a separate fuse and disconnect. They also indicate to install close to the battery. They also say the fuse should be 25A.

It sounds like if anyone is doing anything, they are only using the fuse (i.e. no quick disconnect option other then removing fuse). Ron's installation is the closest to following the recommendations. Wire size and fuse size. I have not found aany "inline" fuse option that can handle #8 wire (I found one for #10, which could be the smallest you could say is acceptable. Installation guide recommends #10 only for under 5ft.).

I don't understand why there isn't a more obvious answer/solution to this problem.

Ron (and anyone else), do you have a picture of your fuse / battery installation?

p.s. Is anyone using the Battery temperature sensor? Can you use one for every bank?


Thanks

[Ron Hill]

pjco : The "obvious answer/solution to this problem"  is to follow the manufactures recommendations!!.
I'll need to take a picture.   

[pjcomeau]

Ron, I want to follow recommendation. I was commenting on lack of obvious fuse solution/product.

Thanks,

Pierre

[Stu Jackson]

Thermal circuirt breakers are made by Blue Seas and sold by WM and Defender. 

They look like this:  http://www.defender.com/product.jsp?path=-1|328|296553|299262|825429&id=825214

For some reason I can't find them in WM's online store, but they are in their catalog.

[Stu Jackson]

Battery Temperature Sensors

Pierre, you asked about this.  I have found that many folks who upgrade their chargers and alternators do install temperature sensors, on either the house bank or the alternator or both.

However, the reasons for the temperature sensors is twofold:  one, to adjust the charging voltage based on temperature automatically instead of manually through the charger or regulator controls, and two, to provide automatic shutdown in case of battery runaway.

I have rarely, if ever, heard of battery runaway on this website (past ten years).  If the banks are properly fused, this becomes less of a safety issue related to danger and damage.

So, the use of the temperate sensors would be for the first instance.  In my particular climate, the water temperature is almost always around 57 degrees F, regardless of the air temperature, which is relatively constant within 20 degrees.  The location of the batteries keeps them cool.  So I have found no need or use for the temperature sensors.

For those in warmer climates, or back on the U.S. east coast, where air & water temperatures can vary significantly, I would recommend the use of the sensors.

In your neck of the woods, you may experience the same conditions we do here, if your water and air temperatures remain constant.  Only you can tell.

The "other" argument is that the temperature sensors can "catch" overcharging and shut the charging source down in the event the batteries become overcharged.  I haven't heard of that either, but it is a good reason to consider installing sensors.  Your boat, your choice.

In most cases, the sensor is tied to one battery in the house bank, not to each individual battery or even individual banks.  The alternator output and the charger output should be led to the house bank, with a combiner, echo charger, relay or switch to charge the start bank.  If your alternator output is still led through the 1-2-B switch, you should consider removing it and rerouting it to the house bank.

[Ron Hill]

Guys : The temperature sensor is a fine piece of equipment for the True Charge 20, but I didn't think that I really needed it. 
If you look at the front of the charger itself it has a temperature selector switch :
  COLD for below 50F
  WARM for 50F to 80F
  HOT for above 80F
I have never used the Cold position and when it gets hot outside (above 85), I switch it from the WARM selection to HOT position.  As the manual tells you - leave it on HOT if you are in doubt so you can't overcharge the batteries. 
I'm on the 4th year with my 3 (#31) house AGMs, stay at anchor about 110 nights/year, only turn ON the charger at the dock if the fridge is ON and haven't had a problem with the batteries to date - they like it.

[pjcomeau]

Ron,

On your last comment about when you turn on your charger. I'm a very new/green sailor and currently the boat during our short season spends most of the time back at the marina with shore power available. On my previous boat (just got the 34 this past December - not use it yet), my regular routine after bringing her back was to plug in the shore power and then turn on the charger even though very little of the battery had been used.

Was this a bad habit? I will have refrigeration in the 34 and will want to keep cold drinks between visits, so in this case, I will definitely will want to keep the same habit (right).

Thanks

[Stu Jackson]

Pierre, your new charger will do just fine as you describe it plugging in with "almost full" batteries.  If you read in the instruction manual, it describes the smart three stage charging sequence of operations.  It will reduce the output based on the acceptance level of the bank(s) and will go to float stage and keep the batteries healthy.  No problem.

It is your choice to run the fridge and keep the boat plugged in, keep it plugged in with the fridge off, or not plugged in at all.  Many of us keep it disconnected from shorepower.  Others like their cold drinks.

I recommend that you do a search on "fridge" and do some reading on this subject.  One hit is this: http://c34.org/bbs/index.php/topic,980.0.html

[Michael Algase]

I have a truecharge 20+ as well, but with new batteries the year I installed it, I only got ~2+ seasons out of them before I noticed low water in all of the cells.  Even though it is a "Smart" charger, even a slow trickle across the cells will liberate water . . .

I have a slightly different solution.  I have a 12V power supply that runs on 120VAC.  The output of that supply goes to the NO position on a DPDT relay with a 120VAC coil.  The NC side of the relay carries the House bank leads from the panel.  When I plug into shore power, the 120VAC coil flips the leads to the NO side, drawing from the supply.  When I leave the dock and disconnect, the relay deenergizes, and the fridge gets power from the house bank.  Have  to remember to have the switch turned on at the panel.  (Note: I have positive on one side of the relay, and negative on the other.  The 'Common' for the NO or NC on either side connects the corresponding positive or negative to the Fridge).

The supply is about the cost of a pair of batteries, and if I get 1-2 extra seasons out of a set because I can turn the charger off during the week, I still keep the beer cold, and save on batteries.

Hope this makes sense.  I can make a diagram later if I have you totally confused.

Michael

[Stu Jackson]

Michael, you wrote: "I only got ~2+ seasond out of them before I noticed low water in all of the cells."  This sounds unusual to me.  I must trust that you check the water levels on a reasonably regular basis and keep refilling a little, rather than finding out two years later that the water level has dropped.  Normal charging of batteries, even on a trickle charge at float, will use some water,as you noted.

FWIW, the Adler Barbour manual recommends that power always be drawn from a battery, and not from a direct power supply of any kind.  Glad to hear it's still working.

[Ron Hill]

Pierre : If I'm not using any DC power (fridge or cabin lights etc.) at the dock, I don't see a need to turn on the battery charger if the batteries are topped off at a 99+% charge. 
I have what I need with AC power - lights, CD music and any other AC item ie. drill/sander/trouble light/computer/printer/hot plate etc. Guess I don't believe in having something ON just to have it ON if it isn't needed!
Maybe that's why my last silicone rectified charger was still working after 17 years when I replaced it with a smart TrueCharge 20+ charger. 

[Stu Jackson]

Just to add to this, if, as Ron says, at the dock with batteries full and no fridge on, the only DC load we see during the day is the stereo.  Based on both research beforehand and now the use of our Link 2000, I can report that the stereo, a car radio/cassette deck/10 disc CD changer, draws less than one amp (four speakers).  This is less than the 3.5 amps (in red) that I penciled in in my energy budget spreadsheet (although not spread out in the calcs, sorry about that) posted here:  http://c34.org/bbs/index.php/topic,3976.0.html 

A separately powered amp for speakers or a sub-woofer will use more.

[Jon Schneider]

If I'm not using any DC power (fridge or cabin lights etc.) at the dock, I don't see a need to turn on the battery charger if the batteries are topped off at a 99+% charge. 

There's one good reason for keeping your charger on: more boats sink at the dock than at sea.  Giving your bilge pump(s) running or at least running longer than a single bank's charge is critical.

[jmnpe]

The correct answer for the use of an extra fuse with the Truecharge 20+ or 40+ ( or any charger...) is to place it close to the battery to protect the wiring from the battery to the charger. As noted, the charger already has internal fuses on each output ( 30 amps on the 20+, and 60 amps on the 40+ ). The goal is to keep the wiring from the battery back to the charger from becoming a "hot wire cutter" if there is a short to ground on the battery charger lines. If you go with the same fuse rating as the internal fusing of the charger ( i.e. - 30 amps and 60 amps ) with appropriately sized wiring, you will be fine. For the 30 amp fuse, you can use a simple inline AGC or ATO/ATC fuse and holder. For the 60 amp fuse, you can use a Maxi fuse and holder if you want to look elegant, or you can do what the Truecharge 40+ does internally - a pair of ATO/ATC 30 amp fuses in parallel for a lot less money. Not elegant, but does provide the required protection.

John