Recommended Battery Isolator for Ram ProMaster with 220 Amp Alternator

Updated 09/02/2024 | Published 01/18/2023

Products Featured in This Question

Redarc Smart Start Battery Isolator - 12 Volt - 200 Amp

(12)

$330.00

Redarc Smart Start Load Disconnect for Manager30 or BCDC with Lithium Battery - 12 Volt - 100 Amp

(4)

$165.00

Question:

Question about the Redarc Smart Start Battery Isolator - 12 Volt - 200 Amp Item # 331-SBI212 I have a 2020 Ram Promaster being built as a camper. Will this item work with a 220 amp alternator and a lithium ion 12v battery in addition to the lead acid starter battery. Thanks

asked by: Tony C

Helpful Expert Reply:

In regards to battery isolators, they should be rated at or close to the changing amperage rating of your alternator. They don't really need to exceed this as it's very unlikely your alternator will ever reach its max charging amperage therefore, I recommend the Redarc Smart Start Battery Isolator part # 331-SBI212 which is rated at 200 amps and the highest we offer. That said, these don't work with lithium batteries and the highest rated battery isolator we do offer for this is the Redarc Smart Start Load Disconnect part # 331-SBI12-LLD which is rated at 100 amps.

In other words, we don't have the prefect solution for your setup but we do have one that will work if you consider a lower amp alternator or non-lithium batteries.

expert reply by: Conner L

Kristofferjohn

8/31/2024

I am curious as to WHY it does not work with the lithium batteries?

Kevin C.

9/2/2024

@Kristofferjohn Isolators can restrict the charge to the battery and cause issues getting it back to full. Lithium batteries need a special type of battery isolator because of the differences in charging and discharging rates between lithium and other battery chemistries. There are other smart isolators on the market that can safely isolate a lithium battery, without affecting its ability to be fully recharged with a higher capacity than the # 331-SBI12-LLD if that's what you're needing.