batteries

[Johnson110]

Questions, I have a 24 ft chapperal with 2 batteries, one is new start battery, 900 mca, the other is a 825 mca both powermaster brand. When I charged the 825 mca ( is not new) one cell does not bubble, it has 12.62 volts on it, Is this battery toast? I have another marine battery 650 mca dated 07 which is good, if the 850 mca is no good, can I use the 650 mca in place of it? Thanks for all input!

 

[john from md]

Re: batteries

Checking the volts of a lead acid battery does not tell the capacity of the battery. You need to buy a hydrometer from an auto store and check the specific gravity of the electrolyte. If you live in a cold climate or go off shore, I recommend that you buy a high rated discharge tester. These can be had from Harbor Freight for $20-$25.

Regards,

John

 

[bruceb58]

Re: batteries

Measuring battery voltage will tell you if a battery is fully charged. 12.62 would be a fully charged battery as long as you took the measurement for an hour after you pulled the charger off. Measuring the SG is the best way but battery voltage is also very accurate.