Proper "Float" Voltage?

[Oldersalt]

My new-to-me 1990 GB 32 has a Xantrex Tru-Charge 40. It also has all-new flooded batteries because the older ones on the boat were totally fried. After 24 hours of charging, the charger still seems to be charging at 13+ volts. This seems high for what should be "float" voltage at this point. Could this be what killed the last set of batteries?

Any thoughts on this?

Thanks for any and all help!

Oldersalt
Happy new GB owner

 

[Panacea123]

Check w/the batt maker, but sounds normal, mine is 13.2v

 

[Bruce B]

My new-to-me 1990 GB 32 has a Xantrex Tru-Charge 40. It also has all-new flooded batteries because the older ones on the boat were totally fried. After 24 hours of charging, the charger still seems to be charging at 13+ volts. This seems high for what should be "float" voltage at this point. Could this be what killed the last set of batteries?

Any thoughts on this?

Thanks for any and all help!

Oldersalt
Happy new GB owner

I would look to the battery manufacturer for this information. I know that Lifeline actually publishes a technical manual that discusses the correct voltages at various temperatures for different states of charge.

Also, some of the better charger take battery temperature into consideration when charging so you need to know how the charger is set up to have a good grasp on the situation.

Bruce

 

[Baker]

Yep the battery maker is the best source. Mine are Odyseey so have extensive technical information on the web. Maybe yours does too. If you don't have that number then google around. I have AGM...I want to say mine float in the mid 13s.

 

[ksanders]

Flooded cells "float" at 2.15 or 2.25 volts per cell or 12.9 volts to 13.5 volts total. The exact number depends on whether the cell is a lead Calcium or a lead antimony construction.

At 13.2 volts your flooded bank is in the range I would expect it to be once fully charged.

 

[kchace]

Like others have said, the best place to go for info is the manufacturer of YOUR batteries. When I need quick battery info, I usually go to the Trojan site which has a lot of detail. In their case, they recommend 13.5V for flooded battery float voltage.

Ken

 

[Ski in NC]

Mine holds 13.2 for float voltage. Batteries seem happy.

 

[ranger58sb]

Yep the battery maker is the best source. Mine are Odyseey so have extensive technical information on the web. Maybe yours does too. If you don't have that number then google around. I have AGM...I want to say mine float in the mid 13s.

Agree, info from battery maker.

At least one Odyssey ref for our batteries says 14.7 bulk/absorption and 13.6 (no more than 13.8) for float.

But each maker's specs can be slightly different, so that's the best source for OP.

-Chris

 

[High Wire]

...because the older ones on the boat were totally fried.

Death by overcharging? Batteries die from several causes. Were the water levels maintained?
"13+" Could be ok, could be bad. Need to get digital with a DVM voltage reading directly from the battery lead posts. Generally speaking, 13.0 - 13.4 float should be ok for FLA.

 

[Heron]

My Sterling 40 amp floats at 13V into flooded GC batteries..

 

[Islanddreamer]

Freedom Marine 2500W float set at 13.40. Seems to keep everything OK.