Charger Modes [Q&A] - REGULAR vs DEEP CYCLE

[Mescale2025]

I have an older Schumacher 12V [2/12A] automatic charger with metal frame and casing. It has a mode switch for Regular vs. Deep Cycle.

Questions:

1. What will happen if i use Regular mode on a FLA Marine battery? Will this undercharge it?
2. What will happen if i use Deep Cycle mode on a FLA Car battery? Will this charge at a slower rate with the possible benefit of de-sulfating/enhancing the battery? No harm, no foul trying this (i would assume)?
3. What mode should i use for the newer AGM batteries?

 

[dnewton3]

The Regular is typically around 8 to 10 amp/hr rate. The Deep Cycle is typically around 2 a/h rate. Slower is better as it causes less stress and heat, if you have the time to let it go to full charge.

 

[f355spider]

I have an older Schumacher 12V [2/12A] automatic charger with metal frame and casing. It has a mode switch for Regular vs. Deep Cycle.

Questions:

1. What will happen if i use Regular mode on a FLA Marine battery? Will this undercharge it?
2. What will happen if i use Deep Cycle mode on a FLA Car battery? Will this charge at a slower rate with the possible benefit of de-sulfating/enhancing the battery? No harm, no foul trying this (i would assume)?
3. What mode should i use for the newer AGM batteries?

I would recommend getting a more modern battery tender. I have a similar older metal cased charger. The "automatic" portion is not well regulated and even on the 2 amp mode, it never completely turns off and will overcharge a battery eventually, if left on indefinitely.
It is still a useful charger, but not for maintenance, only to recharge a discharged battery.
When the green light illuminates that the battery is charged (the analog meter as well), remove the clamps promptly.