Do AGM's charge quicker?

pnichols wrote:


Not necessarily. Suppose that the constant voltage power supply has current capacity sufficient to supply "all" that the battery can absorb at the constant voltage that you set the power supply at?

For an extreme example to get at a clear understanding - say a 500 amp power supply that you set to 14.7 volts in order to charge a single 12V Lifeline Group 27 battery. The power supply's maximum current probably cannot be reached before - regardless of what Lifeline may claim - the battery would go into thermal runaway.

What this means is that in order to do true constant voltage charging, the charger must have a current capacity that exceeds what the battery will ever absorb at that voltage.

Yes if you could find an ideal constant voltage source then your always in absorb, in the real world you don’t see many 500 amp 12v power supplies. Even then my two Lifelines would probably get it into overcurrent mode. Who makes 1000 amp power supplies?

And if your batteries don’t like 5C charging its probably good to get a power supply with a adjustable constant current threshold so you can dial in the proper max amps. Some of those power supplies also have timers that will adjust the constant voltage setpoint after it has been reached to a lower setpoint and reset back again if voltage drops beyond another setpoint. They are called 3 stage chargers.