Technical question re: dual bank charger

[COtoFLsurf]

Been reading the posts on-board battery chargers, and debating between a single or dual-bank charger for my 2015 242LS.

Currently, I connect my portable charger to the starter battery, and once that battery is topped-off the Relay closes and starts charging my house battery. This seems to work great and charges both batteries without having to move the charger connections.

If I used a dual-bank charger, the charger would initially sense and charge each battery independently. However, once the starter battery was topped-off the Relay would close and both "charger banks" would be charging the house battery.

What happens if both banks of a dual-bank charger are connected to the same battery? Am I thinking about this correctly? If so, does this defeat the purpose of a dual-bank charger?

 

[Coheeba]

Here is a thread (battery mistake) that I think will help answer your questions, but if not, re ask and I am sure someone will be glad to help.

 

[Mainah]

For anyone who has read my posts I do tend to go a bit beyond what needs to be done. That said I have two batteries of the exact same chemistry and I still went with a dual bank charger on top of doing the engine on mod for the DVSR. The primary issue with your current method would be if your batteries are not the same chemistry (starting, deep cycle, agm, etc all have different chemistries and need to be charged differently. The second issue is the dvsr staying on after charging is complete. One battery is likley giving up electrons to the other and if different chemistries the topped of volatge for each ahould be different but may equalize instead. You are likley giving up
sime battery performance and longevity using your current method. I would only recommend changing to a dual bank charger if you disable the DVSR while charging with either engine on or switch method otherwise the dual bank charger will just end up with nearly the same effect as your current setup.

 

[Coheeba]

(If I used a dual-bank charger, the charger would initially sense and charge each battery independently. However, once the starter battery was topped-off the Relay would close and both "charger banks" would be charging the house battery.)
Yes that is correct but there is a way to disconnect the DVRS when using a charger and connect when running the boat on the water.

(What happens if both banks of a dual-bank charger are connected to the same battery? Am I thinking about this correctly? If so, does this defeat the purpose of a dual-bank charger?)
That is also correct there would be no need to have the dual bank if you only have one battery to charge. A dual bank charger is effectively two chargers in one box. Each acts independently and senses what each battery needs.

 

[COtoFLsurf]

@Coheeba @Mainah, perfect, thanks. Guess I should have been searching for DVRS posts, that is great information. Have done plenty of upgrades and mods to my boat, but avoiding cutting into the electrical system. I use identical Interstate batteries so should be closely matched for charging purposes, and therefore going to stick with factory DVRS configuration. Thanks again JBers, much appreciated.