How Much Battery Water Consumption is Normal?

[4arch]

My boat is mostly a weekender where we’ll go out for a night or two on the hook, draw the bank down by +/- 100 amp hours, and then plug back into shore power until the next weekend. The batteries recharge on a shore charger that’s left on 24/7. Nothing else except an auto bilge pump is left on when we’re not aboard.

The house battery bank consists of four Interstate GC2 golf cart batteries (installed 2013). I try to check their water levels monthly in season and have noticed I’m going through a little shy of a gallon of distilled water between the four house batteries every 6 to 8 weeks. Not having had a bank this large before, I don’t really have a basis of comparison, but judging by how little water I consumed on previous boats, this consumption level seems quite high to me.

The shore charger is a Xantrex Freedom HF1800. It’s not what I would have chosen, but it came with the boat and was practically brand new from the PO. It’s frustrating enough that it doesn’t have an equalization routine and defaults to the inverter mode being automatically on upon shore power disconnect, but I’m wondering if it could also be the cause of my water consumption. The only other charging source is the Balmar MC-614 external alternator regulator.

So, am I actually consuming “too much” water, or is this just a normal amount for flooded golf carts? If it's too much, should I replace the charger or look at other potential culprits?

 

[centerline]

im going to step in the deep of it and say your batteries are using more water than they should...

a properly sized and charged system, being used accordingly, should be able to go 6 months + before needing water.... some systems get a bit of abuse from the user/boat owner and/or the charger that is being used, and they may need more water more often....
if one of the batteries has a bad cell, the charger will be pushing hard to try and charge it up, and will cause the batteries to run hotter than normal and evaporate more of the water....

or if the batteries are perfectly good, it is probably the charger itself is a bit over active....

 

[Don S/V ILLusion]

I'm still using water from the gallon bought 3 yeas ago. Going through a gallon every two months considering your usage is atypical. In the absence of more info on temperature, charge rate, sp gr data, voltage data, etc., the only conclusion here is something is wrong.

 

[Charles Erwin]

Maine Sail will confirm - or not. Your charger use (24/7) has float at too high a value. When you are fully charged measure voltage at the battery posts. Consider also water miser caps.

Charles

 

[Maine Sail]

The batteries are taking too much water even if you were absorbing at 14.8V, though the HF1800 can't, you should not be adding that much with a max voltage of 14.4V unless your battery temps are 95F plus... We need to know your absorption & float voltages measured at the batteries. It sounds like you perhaps run DC dockside loads that are bumping you back into absorption but you suggest you don't.

Set your HF1800 to power supply mode, IIRC this is both dip switches down. This will force the charger to maintain 13.4V -13.5V with no absorption cycle.

If you continue to need water in power supply mode the batts are toast. Also listen to the batteries when the charger is in float, if they are bubbling of making gassing noises they likely got contaminated but impure water and are gassing at far too low a voltage..