acceptance charging rate AGM batteries
Hi all, It is generally thought that acceptance rate for a flooded deep cycle battery is about 12.5 amps per 100 amp-hours of capacity once the bank is at 85% state of charge. I know that accept...
Forum Discussion
Maintaining a safe discharge voltage level is easier. The longer the duration however the fewer the amps permitted. When that magic voltage limit is reached discharging must cease.
An exercise
BCI load test of a 800 CCA starting battery
50% of rated BCI CCA amps is the formula = 400 amps.
A 400 ampere load is imposed.
For 15-seconds
Voltage at the end of 15 seconds of load must not have drooped to less than 9.6 volts (temp comp).
While this example is not a real-life example of RV battery discharging it should show the relationship of how a battery reacts to a load. 9.6 volts is far too severe a load for usage (it's only for testing the battery).
My personal choice for discharge maximum is 20% of total amp hour rating, and that is for limited time loads like heating coffee in a microwave.
What many folks do not have experience with is the fact that excessive discharge loads cause a flooded battery to gas. The same gas as developed when overcharging. A foolish person who tries to start an engine using a shorted starter motor can make the battery electrolyte actually boil. This damages the battery.
An exercise
BCI load test of a 800 CCA starting battery
50% of rated BCI CCA amps is the formula = 400 amps.
A 400 ampere load is imposed.
For 15-seconds
Voltage at the end of 15 seconds of load must not have drooped to less than 9.6 volts (temp comp).
While this example is not a real-life example of RV battery discharging it should show the relationship of how a battery reacts to a load. 9.6 volts is far too severe a load for usage (it's only for testing the battery).
My personal choice for discharge maximum is 20% of total amp hour rating, and that is for limited time loads like heating coffee in a microwave.
What many folks do not have experience with is the fact that excessive discharge loads cause a flooded battery to gas. The same gas as developed when overcharging. A foolish person who tries to start an engine using a shorted starter motor can make the battery electrolyte actually boil. This damages the battery.
