GOOD battery maintainer?

[AH64ID]

For a short time there shouldn’t be any issues, but long term you don’t want 2 chargers on 1 bank.

 

[BigPapa]

The way our two batteries are connected, they are essentially one battery. I don’t think you’d put two chargers on one battery or connect two chargers together, would you? So, if you want to put a charger on each battery, separate them where they’re actually two batteries.

I don’t KNOW that there’s any DANGER to it, I’ve never tried it, and I don’t know what results you’d get if you do. With the “smart” chargers, would they charge at all? If one charger starts charging, would the other see full power and kick off or into “maintenance” mode? Maybe, I don’t know.

 

[AH64ID]

2 chargers can be used for bulk charging, but it’s not a normal practice for float charging.

Multi-Bank chargers are for multiple individual batteries on the bench. A single trickle charger can be used for multiple batteries as disconnected batteries don’t need to be hooked to a charger constantly.

I have the NOCO 3500 I use mainly for the Ram, and a NOCO 750 I move around to my other batteries every couple months. The 750 isn’t hooked to anything constantly.

 

[lpennock]

Hooking 2 chargers in parallel won't hurt the batteries but could hurt the chargers. It is possible for one to be in bulk charge while the other is in float charge. Depending on how the charger in float responds to over voltages (Bulk runs at higher voltage) it could damage the one in float. With that said it probably won't bother good chargers as they are designed to handle the car being started while the charger is connected.

 

[Mike Wenrich]

I've been using the Battery Tender Plus model that charges two batteries with two separate lead pairs for a 24 volt military Jeep. I have the ground disconnected on one battery. Then hook the charger to the two. Have done this for years with no ill affects to the batteries. The charger seems to know because it charges them separately. The charge lights go off at different times. This may not add anything to the discussion since I have one lead disconnected but might explain what the charger does. The reason I disconnect the ground is that I have a small voltage draw somewhere in the system that I cannot find. Maybe the method has protected the batteries. The last pair (NAPA) lived for 5 years and I replaced them before going to a meet just so I would not be stranded. Also one of them was reading a little weaker.

 

[lpennock]

The battiers in a 24V system are wired in series so putting a charger across each one is different that on these trucks. Separate 12V chargers directly on the battery is the correct way to charge a 24V system with 12V chargers.

 

[MichaelOverfield]

In a recent brain fart, I did just that to my truck(i.e. 2 individual battery tenders, one hooked up to each battery) The truck sat that way for over a week and they seemed to charge the batteries normally with no ill side effects to either the chargers, the batteries or the truck, which I have driven since.

That said, I am curious as to why you think it is a terrible idea??

Because the electronics in the charger is looking for battery voltage and adjusting the charge rate and output accordingly. If you have 2 chargers connected, each is sensing not the battery voltage alone, but the battery PLUS the other charger's voltage, and they would incorrectly adjust output based on an incorrect reading. That is why when connected together, connect only ONE charger for a maintainer.

 

[FOXY005]

I have seen several brand names mentioned here and would like to know if there is a specific brand of battery maintainer that is recommended for AGM batteries?

 

[AH64ID]

I have seen several brand names mentioned here and would like to know if there is a specific brand of battery maintainer that is recommended for AGM batteries?

I went with a NOCO 3500. It has modes for normal, AGM, lithium, and 6V... as well as a repair mode.

It's also deeply discounted right now as NOCO is releasing a new line of smart chargers.

 

[MichaelOverfield]

I have seen several brand names mentioned here and would like to know if there is a specific brand of battery maintainer that is recommended for AGM batteries?

I have Odyssey AGMs, they have a list of approved battery chargers for use with their AGM batteries... on that list was the Minn Kota Charger that I used and linked in an earlier comment. So far it has worked very well, it is mounted under the hood on the passenger side behind the A/C receiver on the fender, it fits well there and the cord is run out next to the block heater cord, so I have 2 plugs (for now).