Battery charge times

[jcbasser 52]

I have 3 intimidater 31 agm batteries for my ultrex and after a day of fishing they re charge in about 2 -3 hours. These batteries are 4 years old. I have a X2 31 agm dual purpose cranking and accessory battery that is about 15 months old. I have 4- 12" graphs but only run 2 or 3 at a time and often place the rear ones on standby while up on the front deck. It takes at least 6-8 hours to charge the X2 battery. Is it possible to remove one of the other battery leads and add it to the X2 battery to boost the charge from 10 amps to 20amps???? I have the Dual pro sportsman 4 bank 10amp std charger that came with the boat.
Thanks for any input.

[CatFan]

The extra power is of most benefit earlier in the charging process. As the battery charges you won’t even get the battery to take 10A eventually. Though it might help, it’s probably not worth the effort.

[haus9393]

Better off buying a separate 1 bank 10-15 amp charger to add to that battery when needed.