Charles 3000 Charger -- Dual Battery Charging

[ccvalentino]

Hello,

On my C-350 Dreams of Blue Hull# 176 I have 2 battery banks (Bank #1 House and Bank #2 Single Group 31 Battery).

On my last trip out I discovered that battery #2 was dead. This was after I forgot to turn the breakers back on from my prior trip. So, I chalked it up to the battery not being charged and maybe it was getting a little weak. I started the engine on Bank 1 and moved my battery switch from 1 to all to 2 and motored out. On my return trip, the engine fired up on Battery #2 and I motored back in (short ride for me about 15-mins).

Upon further investigation I found that my battery charger was charging bank #1 but not bank #2. I pulled the fuse from the battery charger feed and found that the 30AMP fuse was blown. Another tidbit was I purchased Dreams of Blue last year and was following the instructions on the boat that stated that Bank #1 was the Group 31 battery and Bank #2 was the house -- as described above this was backwards. So, for an entire year I've been giving preference to Bank #2 for everything (starting the engine, running my 12V systems at anchor/mooring). Essentially, I've not been utilizing my house batteries (2x4Ds) in Bank #1.

In addition, I also noticed that I was getting repeated bubbling out of my 4D batteries. I'm starting to think that Bank #2 was getting depleted and the Charles 3000 charger was sensing low voltage and going into a full charge cycle and charging Bank #2 but also overcharging Bank #1. So, here lies my question -- is the Charles 3000 designed to charge 2 independent battery banks or is it designed to charge 2 batteries in the same bank with same level of consumption and depletion? This would explain the bubbling on the 4Ds and probably the blown fuse by oversupplying power to Bank #2 from Bank #1 (when it goes into a full charge cycle).

Thoughts are appreciated.

Thanks,
Chris

[KenKrawford]

Chris, my battery setup is similar to yours. I have 4 golf cart batteries wired together to form one 420 amp hour bank and a group 27 "starting battery" as bank 2. I use bank 1 for everything and only start the engine using bank 2 once or twice a year to make sure its still working properly. The Charles charger should charge each bank independently sensing which bank needs charging and how much.
My Charles charger died last year and I replaced it with a Sterling Procharge Ultra. It's also sold under the the Promariner name. It's been great so far and offers a number of features that the Charles didn't.

[ccvalentino]

Thanks Ken. Good to hear you have a similar setup. I’m going to reconnect the second today and go from there.

Chris

[JohnNorton]

I believe the Charles charger is not a "smart" charger. I sees your batteries and one type, capacity. It will not charge two different battery types at an equal rate. Seems you could use it to charge your existing batteries- but only one at a time. If you want to leave the switch on "both" when charging your batteries should all be identical. And the standard wisdom is if you need to replace one battery- you need to replace them all ("weakest link" sort of thing).- John

[ccvalentino]

Thanks John. -- adding Charles 5000 (wrong model number in my subject), so that this thread is searchable with the correct model number.

Chris

[KenKrawford]

John, why would the position of the battery selector switch affect charging? This is a positive wire from the charger to each battery bank. The Charles will support 3 banks.

[cuthbert]

I am unsure if the Charles charger has independent channels charging on each channel, I recall it did not, I know that the Mastervolt I replaced it with does not appear to also. To clarify that comment, I have the typical setup - large house bank (400A/h of 6V golf cart batteries) and a type 26 backup/starter as the other bank. The charger is connected via individual fused wires that go directly to each bank. I leave the 1/2/all switch on 1 (house bank) even for starting and therefore when the engine is running the alternator is only ever charging the house bank. When I have partially discharged the house bank to 80% plus and connect shore power the charger seems to put both outputs in absorption mode the house bank voltage is measuring 13V+ depending on how discharged it is but the fully charged and unused starter battery is at the full 14.4V absorption voltage, the charger doesn't detect it as having a full charge and change that channel to the float voltage (13.2-13.6 - depending on manufaturer). The part that makes this difficult to work out completely is each power supply design incorporates some amount of absorption change on initial connection even to a fully charged battery, but still it holds the starter battery to a high voltage for longer than necessary. This is a little bit disconcerting but I have not had a gassing problem thus far (a fair few years), and I check the acid levels regularly. If I have used the house bank such that its in the 50-80% charged range and the charger will be going into bulk mode, I combine the battery banks by turning the battery switch from "1" to "all" so that its not further overstressing the starter battery as now both banks are combined and the charger detects the same load on each output.

I also put the switch on "2" once a year and check my starter battery will get me out of a bind if something bad happens. One thing to note about the switch it is "make then break" so as you go from 1 to all to 2 there is never a moment that there is no applied 12V volt for the electronicsin use.

The Charles charger in float mode did lead to regular top ups of distilled water when I had 4Ds on the boat. Although the Mastervolt charger has a lower float voltage I find it easier to just switch it off when I'm not at the boat and put a charge back in every week or two weeks in the winter if not sailing. I don't have the stereo direct 12V wire to retain the memory and so the total current draw is effectively zero. Of course if the boat sprung a leak such that the bilge pump was going 100% it would flatten the batteries in some time period, but its stayed watertight for many years.

[JohnNorton]

Ken: On my 350 when I have the battery switch on No. 1 the charger seems to only be charging bank No. 1, on #2, only bank #2. On "Both" it charges both banks. Perhaps wired incorrectly ? Anyway, if this is how my charger works, seems best to have matching batteries when switch is set to "both". If I have different batteries/types seems I'm asking for trouble. Possibly why Chris had the issues he discribed; then again perhaps I am wrong on this. - John