Charging question re: starting battery

[hrifraf]

My setup is a single engine, one alternator, external Balmar regulator charging the house bank (5 4D's) and then the start battery (1 4D) via the ACR. My concern is that the start battery is wet on the outside. There is battery acid on the top of the battery. I am guessing that the start battery is somehow being overcharged and boiling over?



I was thinking of switching the ACR out for a Xantrex Echo Charge, but reviewing past threads on this forum, my setup seems to be a common one so now I am wondering if anyone else has had this kind of experience.



The boat is a recently acquired 2011 North Pacific. The Balmar died shortly after purchase, which I then replaced and programmed for the house bank needs. The house bank seems to be performing just fine.

Any suggestions would be appreciated.

 

[Aquabelle]

Balmar's Digital DuoCharge (DDC) is designed specifically for your situation. Its great advantage over the EchoCharge and ACRs is that it is pre programmed for different battery types. This allows you to use one battery chemistry (e.g. flooded 6V golf carts) for the House bank and a chemistry better suited to starting and other brief high amperage loads (e.g. spiral wound AGMs) to be interconnected via the DDC.

 

[DavidM]

Is it possible, a long shot perhaps, that the starting battery was overfilled and the wetness is from electrolyte sloshing out and not boiling out?


If not, this is the first case I have heard of where a high output alternator, charging both a large house battery bank and a starting battery (through an ACR) is overcharging the starting battery.


I am not sure that it is all bad. Overcharging a starting battery with filler caps long term just boils out a bit of electrolyte. As long as you replenish the water and don't let it get below the plates, I don't think it does anything bad. Sort of like continuously equalizing.


But the Balmar DuoCharge should solve the problem. I think the Echo Charge just passes on the input voltage to the starting battery, but with a 15A current limit.


David

 

[CMS]

Guys,


Both the Echo Charger and Balmar Digital Duo Charger can only impose a limit of the output voltage. The Echo charger limits this to a max of 14.4V (fixed) and the Balmar DDC can be programmed for lower than that but, over time, this can wind up under charging a start battery.

Both of these devices are simple voltage followers not independent "three stage DC to DC chargers". This means they follow the voltage of the house bank and can only impose a voltage cap/limit. In other words they can not drop a start bank to float while the house bank is in absorption.

If one desires a true multi-stage DC to DC battery to battery charger then the Sterling Power BB1230 is the Mercedes of the class. In certain situations these are really a great fit, but for like chemistries, not entirely necessary.

If a battery being charged by an ACR is off-gassing more than the house bank this is most likely because the battery is simply tired and done for or over-filled but not likely due to the ACR.

 

[bayview]

It is possible that the start battery is getting old. have you measured the specific gravity?

 

[hrifraf]

Thank you everyone for your suggestions and excellent information.

Yes, it is quite possible that the starting battery is aging. Not sure of the exact age of the battery, but I will check the specific gravity next time I am on board. In any case, it is reassuring to know that the charging setup is not likely to be the problem.


Cheers;
H