Keeping water in batteries

[ttom02]

I have been having trouble keeping the water level up in my batteries. I have four 8 volt batteries in each engine room and they are charged by a fairly new Sentry 30 amp charger. Problem is that I have to add water monthly - just under a half gallon per battery. This seems to be excessive. I have had the charger checked to see if the output was too high and it checks ok. Does anyone else have this problem? Is this normal? I also have a 12 volt battery for electronics and four 6 volt batteries for my inverter and they do not require water to be added but maybe once every six months. Thanks for any comments.
Tom

[PascalG]

I have 2 banks of 4 8 volts batteries and altogether I add a little under 2 gallons a month.

I have a timer on the charger but noticed it doens't work... I'm going to change it which shoudl help as it will reduce the amount of time the charger is on.

[rufuschamblee]

Here is a site you might want to check out. Due to the location of batteries on my 42C, I am going to install a system when they are available for 8d batteries. Check with them to see id the already have a system for your batteries

Rufus

[rufuschamblee]

here is web site for battery filling systems--www.flow-rite.com

Rufus

[jim rosenthal]

I find that all of the chargers I have had, no matter how good they are, boil a certain amount of water out of the batteries. 1/2 gal a month per battery seems like a lot. What is the float charge in volts of the charger, if it goes to float once it has charged the batteries? If it too high, they will lose water.
I also had this problem (see an earlier post) because I did not have an adequate return path for the charger. The negative path to the charger was smaller in gauge than the positive path. I installed a separate set of returns also of 4 gauge cable and that improved things a lot.
If your charger has a temperature compensation switch, make sure it is set for the ambient temp in the engine room, or the next lower range. Batteries tolerate charging less as the temp goes up.
Finally, after a full charge, you might turn off the charger altogether, let the batteries equilibrate, and check each cell with a hydrometer. This will tell you whether they are really charged, or use a digital VOM like a Fluke. A modern charger should be 'smart' enough to fully charge the batteries, sense that, and then float them just enough to keep them topped off without losing water. Perhaps the charger isn't sensing the battery charge properly.

[ttom02]

Thanks for the info guys. Jim, I think you may have hit the nail on the head with the ambient temp. I never considered the fact that I don't have near the problem in the winter as in the summer. The temps here have been in the 90's for a couple months.
I have checked the output on my charger and she is doing about 34 to 37 volts. I need to check to see where it kicks out to determine if it "really" is cycling.
Thanks,
Tom

[dshuman]

My 1978 53MY has had that problem when my older charger bolied my starting bank all the time. It only has a sensor for the house bank, which it keeps perfectly charged without boiling them much. The problem was that the separate starting bank is only used to start the s/b engine so it doesn't need much recharge and the charger gives the same amps to both banks every time it charges the house bank.

I connected the charger to only the house bank only and let the starting bank get recharged from the engine's 50 amp alternator. Newer chargers can "float" multiple banks, mine doesn't, so it boiled one bank all the time.