Battery Upgrade / Onboard Charger

[BlackoutATX]

I'm upgrading my stereo bank to 4 group 31 Deka AGM batteries. This will give me 420ah. This will be replacing 2 6v Interstates at about 207ah. The current setup is hooked up to a Promariner 20 and has done just fine. From the research I've been doing, there tends to be a split opinion on the matter of onboard chargers. I have not personally spoken with ProMariner support. But they apparently say (and others as well) that a 10-15% to ah rating is what you should look for in a charger. However, it appears many are running lower level chargers on larger systems like this with no problems. Is there any truth to this at all? These charger get pretty expensive the higher the amps go. If this is true, any recommendations on a new charger?

[chpthril]

I like the 10% rule. I think it allows enough bulk charge to de-sulfate the batteries without overworking a small charger.

[BlackoutATX]

I should have just messaged you Mike! With my cranking battery at 81ah, that puts my total at 500ah. You think I could get away with a 40A charger? Any disadvantage to running an additional 40A charger along with my current pro mariner 20? If I went that route, I would have a total of 60A and each battery would have its own lead connection. Any problems with running two different chargers on the same battery bank? I have my eye on this one because of its small size.

NOCO Genius GEN4 40
https://www.amazon.com/NOCO-GEN4-Wat...ius+charger+40

[BlackoutATX]

Just wanted to share my convo with a NOCO rep....

Dan:
Any questions?

Caleb:
Hi Dan. I have a 2015 Tige RZ4 that I'm upgrading the battery system on. 1 bank (Stereo) will have 4 AGM batteries for a total of 420ah. The other bank will have one cranking battery at 81ah. I currently have a pro mariner 20. I'm trying to figure out what the best method is for charging this system. I have been told to use the 10% of ah to find the Amps needed in the charger. What would you recommend?

Dan Brown:
We recommend charging each battery individually whenever possible. For a system with five 12V batteries in it I recommend using a GEN4 4 bank charger for the parallel set up
you can leave the batteries connected in the system and have a charge lead for each battery
then using a GEN1 or GENM1 on the starter battery
The GEN4 will supply 10A per charge bank
so each 12V battery would be charged as if stand alone

Caleb
Is 40A enough for the 420ah bank? I've been told that not enough A per battery (under 10%) will not allow them enough charge to de-sulfate the batteries.

Dan Brown
each charge lead is rated up to 230Ah battery
since each battery will have its own lead you will be fine
what are the individual Ah ratings of the batteries

Caleb
I see. one more question. Would you see any problems with only using 3 of the 4 leads to the stereo bank and using my current 20A charger to charge the cranking battery and the last stereo bank battery? This way I could get max As to all the batteries?

Dan Brown
No, I do not see any reason why that would be an issue.

Caleb
Each battery would still have its own lead, I would just get more A's into the system.

Caleb
Great Dan. Thank you for your help.

Dan Brown
you're welcome

[JohnnieMo]

For what it's worth I'll throw my vote in with NOCO. I run a 2 bank version of this on my boat. I've been very happy with their products.



This appears to be the one he referenced in his chat with you.

[BlackoutATX]

Battery Upgrade / Onboard Charger

For what it's worth I'll throw my vote in with NOCO. I run a 2 bank version of this on my boat. I've been very happy with their products.



This appears to be the one he referenced in his chat with you.

Yes that's correct. They also have incredible reviews across all their lines on Amazon. I ordered the 4 bank and the smaller one bank. Going to just sell the promariner.