Gel Battery Question

LeslieTroyer · Feb 26, 2019

Keeping the same battery chemistry thru out the boat simplifies your charging system. If you go with fla start battery, unless you spend lots of cash the charging parameters for at least one bank is sub optimal.

I would also recommend moveing the alternator to the house side and charge the start battery with an ACR.

Les

Maine Sail · Feb 26, 2019

Rick486 said:
Hi Maine Sail:
I am about to replace all the batts in my Hunter 44DS. The original batteries are 3 x 4D Deka gels and an Exide Gp 24 gel starter. They lasted 11 years, so I am happy to replace with kind.

GEL batteries, specifically Deka and Sonneschein Prevailers, are excellent deep cycle batteries provided they are charged correctly.

Rick486 said:
So my question for you is:
Is it necessary that the starter be a gel batt? I can see no reason that it shouldn't be gel but I thought I would get your thoughts.

Keeping it GEL means both battery banks will see the same charge profile which should be 14.1V to 14.2V MAX. if you try to charge an AGM or Flooded at 14.1V to 14.2V they will not last as long as they should. You could do this with a Sterling Battery to Battery charger but if the GEL starts your engine then stick with what has worked.

Rick486 said:
The start charges off the alternator with the Yanmar running and a trickle charger off the inverter/charger with the generator running or dockside power hooked up.
Thanks in advance
Rick

Your alternator should ideally feed the house bank directly then an ACR or Echo Charger, Duo Charger or Sterling B2B can charge the start bank from the house bank......

Stu Jackson · Feb 26, 2019

Rick486 said:
Is it necessary that the starter be a gel batt?

Yes it is unless you want to complicate your charging system.
Why?
Simply because the charging voltages for gels is much less than that of FLA or AGM banks, and will undercharge the FLA if you set the charger to the lower gel voltage.
Other side of the same coin:
The charging voltages for FLA or AGM is much higher than for gels and will damage the gels if you set the charger to the higher AGM/FLA voltage.
Yes, AGM is an FLA, absorbed glass mat compared to simple flooded lead acid.

SEMPERAVANTI41 · Feb 26, 2019

I have 3 Deka 8D gels and a AGM start battery. AC charger and Balmar external regulator are set for AGM voltage. After 3 years no problem.

Maine Sail · Feb 26, 2019

The only good way to really mix a flooded or AGM start battery, and charge from all sources, with the house being GEL, is to use a product such as the Sterling Power BB1230 DC to DC battery to battery charger. This is a true DC to DC battery charger that can either boost or reduce charge voltage to the AUX bank as well as give it its own independent charge profile.. In other words you can set all charge sources to GEL 14.1V, feed them to the house bank, and then set the BB1230 to say 14.7V for an Odyssey TPPL AGM. The Sterling B2B chargers are the only true three stage battery to battery chargers we know of that does not just follow the voltage profile of the house bank (Echo Charger / Duo Charger etc.). A very, very cool product but not really necessary if you stick with a GEL start bank..

Maine Sail · Feb 26, 2019

SEMPERAVANTI41 said:
I have 3 Deka 8D gels and a AGM start battery. AC charger and Balmar external regulator are set for AGM voltage. After 3 years no problem.

You will be well served to use Balmar's GEL setting or go into the advanced programming menu and create a custom GEL profile of bv 14.2V for 6 minutes then av 14.1V for at least 5 hours then a float fv of 13.8V and always use temp compensation. This is the exact programming that yielded 17 years on a Deka GEL bank....

We have numerous GEL banks out there at 10+ years old and one bank that went 17 years. Not a single one of the banks ever sees more than 14.2V for any more than about 6 minutes maximum. GEL batteries do not live the life they are truly capable of when charged at voltages exceeding 14.1V to 14.2V.

SEMPERAVANTI41 · Feb 26, 2019

The Sterling Power BB1230 does look like a really cool product. As I am happy with the present ability of my start battery, when I need to change I will upgrade to a Gel start. On an off topic subject, I changed the "house" battery in my 2006 MB SL55 to an AGM because the original equipment MB battery is FLA (with a vent line) and costs more with less capacity. I don't know of any other car that has 2 batteries, one in the engine compartment for just starting, and another trunk mounted battery for everything else. I did nothing to change the output of the alternator, and after 10 months all is OK.

SEMPERAVANTI41 · Feb 26, 2019

Maine Sail, should the settings be the same for the Balmar external regulator and the AC charger? Would you use the belt manager on a 160 amp Balmar with a serpentine belt?