Dual Battery Tender

[Punkin Slinger]

Getting a dealer-installed dual battery setup in my new 165 ID. Question is, can I use a battery tender on one battery with the switch set to both batteries to keep them both charged over winter, or do I need to have a battery tender on each battery separately. If so, I would keep the switch set to "off".

 

[Luc Lafreniere]

If the two batteries are the same type, same age ( in other words, same specs and voltage levels), then yes. If they aren't the same, some tenders do fancy things to try and "fix" the battery and such. That could cause the other, good battery to have issues since it doesn't need it.

I'm not sure how they are wiring them up... but if the switch allows you to connect the batteries in parallel (hence, keep 12V but add capacity), then that's what you want to do. If you're unsure, it may be easier to simply disconnect them for the winter, and connect the two batteries together in parallel manually.

There's a whole section on this on the Battery Tender brand's page: Connecting Batteries & Chargers in Series & Parallel

And here's a video from Genius battery chargers explaining all of this in a short video:

 

[Crob83]

I use a dual bank, I wouldnt use a single bank on 2 batteries.

 

[Punkin Slinger]

If the two batteries are the same type, same age ( in other words, same specs and voltage levels), then yes. If they aren't the same, some tenders do fancy things to try and "fix" the battery and such. That could cause the other, good battery to have issues since it doesn't need it.

I'm not sure how they are wiring them up... but if the switch allows you to connect the batteries in parallel (hence, keep 12V but add capacity), then that's what you want to do. If you're unsure, it may be easier to simply disconnect them for the winter, and connect the two batteries together in parallel manually.

There's a whole section on this on the Battery Tender brand's page: Connecting Batteries & Chargers in Series & Parallel

And here's a video from Genius battery chargers explaining all of this in a short video:

OK, here's what I did. I found a 2 pack of 1.2 amp battery tenders from Guide Gear (Sportsman's Guide) for $34.99 + $9.99 shipping + tax. I'll keep the master switch on "off", and attach the tenders separately to each battery.