landyacht318 wrote:
OTC 4619
http://www.amazon.com/OTC-4619-Professional-Battery-Hydrometer/dp/B0050SFVHO
Leave charger on until all cells are 1.275 or higher.
If the wall wart/charger cannot get the cells to 1.275, you need a bigger charger.
After the cells are 1.275, then the maintenance charger should be able to hold them there.
Obsessing over voltage is common but unhealthy. Battery voltage when charging or discharging is like throwing a rock at a rubber band and trying to guess the weight of the rock by how far the rubber band stretched.
Most people cannot even hit the rubber band, much less see how far it stretched, but call their method gospel anyway.
That makes sense to me, but the thing I'm still having a hard time grasping is the relationship between volts and amps during charging. I get that, for example, if I had a charger that only put out 12.5V, it makes no difference how many amps it is capable of, it will never fully charge a battery. But, let's say you have a charger (a wall wart for example) that is capable of 15V but is only 500mA. It should fully charge the battery, it's just a matter of how long it takes. A 1A charger should do it in half the time, but either charger should be able to eventually get there because the voltage is high enough.
Also I get you should charge at 10-13% of the battery's C20. But I guess that's a max? Obviously you'll never get close to that with a wart and I guess that's ok? But what if you connect a 55A charger to a single group 24 battery? Are you going to damage the battery because you'll be charging at close to 70% of the C20?
It's funny, the more I learn, the more I realize I don't know!
