Batteries will not fully charge

[scottyb]

These 2 batteries need some CPR
I would use a 12v charger, preferably one with an amperage option. Connect across the 2 low batteries just like the accessories were and charge at 20 amps until they hit 15v combined then then drop down to 10 amps for 1 hour and then 5 amps for 1-2 hours. Constantly monitor battery temperature. It should not exceed 10º above ambient. Above all check water levels are above the plates in all cells before you start.

[AKavanaughSC]

When y'all suggest a hydrometer, any recommendations?

[scottyb]

Originally Posted by AKavanaughSC

When y'all suggest a hydrometer, any recommendations?

I suggest you save the hydrometer for checking the car's antifreeze. Use a refractometer for undeniable results

[PuttPutt]

Originally Posted by scottyb

I suggest you save the hydrometer for checking the car's antifreeze. Use a refractometer for undeniable results

To funny, I have a automatic temperature compensating refractometer I use when I make beer. Never occurred to me to use it for the batteries.