Batteries Cooking

[seadaddler]

I have 2-4D's and a 20 freedom inverter charger and when I get to the boat a smell cooking battery acid,the acid is bubbling and hot and the batteries are hot.
The remote panel does say 13.5 and 14 charging,so why is it charging so high even after it is on bulk charge.
I shut the charging wait a few minutes and push the charging and back up to 13.5 and the acid is bubbling again and the batteries are very hot,any advice.
Nick

 

[Bill1565]

I hate that smell. I don't think you should charge them any more.

 

[ebsail]

There's nothing wrong with charging at 14 volts. Is this what the voltmeter reads during the bulk charging cycle? However you need to know how many amps the charger is putting out relative to the battery size. During bulk charge cycle you should not exceed 15% of the battery capacity (total amps of all batteries being charged). If you do, you'll get get plenty of outgassing (hydrogen production), thats the bubbling, and water evaporation, and a shorter battery life. Put an ammeter othe charger output line and see what its doing.

 

[Don S/V ILLusion]

Nick
I infer you mean the charger doesn't cut back to float charge with as corresponding decrease in voltage to around 13 and therefore you are cooking the batteries.
Three possibilities:
1. bad connection someplace with a high resistance - easy to fix; hard to find.
2. Bad cell in one of the batteries - easy to find, expensive to replace.
3. charger doesn't sense charge voltage to decrease to float - you know this one isn't good news.
It's only a guess which one so I list in order of cheap to $$$.

 

[seadaddler]

Thanks

I am going away for week but when I return I'll be checking all the things mentioned.
Nick

 

[Ed Schenck]

Nick, cannot remember what the original Freedom 20 remote panel displays. I replaced mine with a Link 2000. But I think there is a way to tell and it should be on "Float" when the batteries reach 13.5 or so.

 

[Barnacle Bill]

I suggest you turn stuff off while away. Because if you are overcharging your batteries, which is what your post suggests, then it could lead to a fire hazard and for sure will wreck your batteries and maybe more. It sounds like either there is no trickle charge feature in your charging equipment, where the rate of charge decreases as the battery reaches it's full charge. If there is no guard, or regulator to sense this and make the appropriate amperage reductions, it will charge the battery endlessly, which is dangerous.