What's new
By:
Ram Heavy Duty Forum

Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Will a Battery Tender Charge both Batteries?

John Jensen said:
According to Battery Tender you should connect the positive clip to one battery and the ground clip to the other battery. That way, depending on what BT you have, the BT sees two batteries and can give you a readout for each battery. If you put both clips on one battery the BT sees both as one battery.

Also, to work properly you need a BT of sufficient amperage. Too low amperage rating and the BT cannot keep batteries at full charge. Been there, done that!
Click to expand...
However, in the latter situation it really doesn't matter in the long run because once the light is solid green that indicates both batteries are fully charged and the tender is trickling both correct? My Battery Tender has one red and one greed LED, won't read out for two separate batteries.
 
lovegolf44 said:
However, in the latter situation it really doesn't matter in the long run because once the light is solid green that indicates both batteries are fully charged and the tender is trickling both correct? My Battery Tender has one red and one greed LED, won't read out for two separate batteries.
Click to expand...
My low powered maintainers also showed a solid light indicating batteries were fully charged but were not maintaining and eventually the batteries went dead. My son had the same experience with his low powered maintainers.

As for reading separate batteries, I said it depends on what BT you have.
 
John Jensen said:
My low powered maintainers also showed a solid light indicating batteries were fully charged but were not maintaining and eventually the batteries went dead. My son had the same experience with his low powered maintainers.
Click to expand...
Hmm, solid green light but the batteries died anyway? That's disheartening. I have a BT Plus 1.25A. What's everyone else using to keep the two batteries properly tended?
 
lovegolf44 said:
Hmm, solid green light but the batteries died anyway? That's disheartening. I have a BT Plus 1.25A. What's everyone else using to keep the two batteries properly tended?
Click to expand...
I'm using a NoCo Genius 10 (10amp) on my two battery Ram HO Cummins and a Noco Genius 7200 (7.2amps) on my one battery Ram Ecodiesel. Got rid of all my less than 5amp maintainers.

I have a Minn Kota, 20 amp, 2-Bank On-Board Battery Charger - # MK-220PC on order to use on my Cummins. Will probably hardwire and mount it permanently.
 
John Jensen said:
I'm using a NoCo Genius 10 (10amp) on my two battery Ram HO Cummins and a Noco Genius 7200 (7.2amps) on my one battery Ram Ecodiesel. Got rid of all my less than 5amp maintainers.

I have a Minn Kota, 20 amp, 2-Bank On-Board Battery Charger - # MK-220PC on order to use on my Cummins. Will probably hardwire and mount it permanently.
Click to expand...

Are you going to hook up both banks on the MK-220PC, one per battery? Since the batteries are connected won’t that mess up with the separate banks from the charger? I’m asking because I wanted to add an on-board charger as well, but thought the dual bank chargers wouldn’t work with the dual battery setup.

I was considering the Noco, but looks like your moving away from it? Does it not work well?
 
Last edited:
I run the 1.25 deltran and my truck didn’t run for months over the winter and it kept the batteries fully charged.
 
IronByron said:
Are you going to hook up both banks on the MK-220PC, one per battery? Since the batteries are connected won’t that mess up with the separate banks from the charger? I’m asking because I wanted to add an on-board charger as well, but thought the dual bank chargers wouldn’t work with the dual battery setup.

I was considering the Noco, but looks like your moving away from it? Does it not work well?
Click to expand...

Yes, one bank per battery. You ask a good question. I assumed that each battery having a ground and positive from the charger it could see it as a separate battery. I assumed this because of Battery Tender's statement when using a one-bank charger (with the sophistication) to put the ground on one battery and the positive on the other. Your question now poses some doubt to my assumption. I'm going to call a couple of companies that have multi-bank chargers and pose the question.
Thanks for the question, makes me wonder :confused:

Edit: The NoCo works great but for its size it's hard to find a place to mount in the truck. Plus Noco advised against putting where heat, vibration and water can reach it. The Minn Kota is made for the marine environment so it should do well on the truck. I've had similar Mini Kotos in my boat for the last 15 years and they are still like new, just dirty.
 
Last edited:
John Jensen said:
Yes, one bank per battery. You ask a good question. I assumed that each battery having a ground and positive from the charger it could see it as a separate battery. I assumed this because of Battery Tender's statement when using a one-bank charger (with the sophistication) to put the ground on one battery and the positive on the other. Your question now poses some doubt to my assumption. I'm going to call a couple of companies that have multi-bank chargers and pose the question.
Thanks for the question, makes me wonder :confused:
Click to expand...

Just curious because I was seriously considering the noco (probably the 10 amp), is it not meeting your expectations?
 
flan said:
I run the 1.25 deltran and my truck didn’t run for months over the winter and it kept the batteries fully charged.
Click to expand...
That's a great charger. BT did not recommend it for my amp hours rated battery, and especially not for a two battery system.
 
The 2-bank charger will work fine. You can even hook up both leads to the same battery if you want and it will put out 20-amps. It is covered in the manual available online.
 
IronByron said:
Just curious because I was seriously considering the noco (probably the 10 amp), is it not meeting your expectations?
Click to expand...
It's a great charger, very satisfied. Just want to go to a 2-bank system with smaller units.

carlrx7 said:
The 2-bank charger will work fine. You can even hook up both leads to the same battery if you want and it will put out 20-amps. It is covered in the manual available online.
Click to expand...
Thanks Carl,
You saved me a couple of phone calls.
 
lovegolf44 said:
I just ordered the Deltran 5amp weather resistant.
Click to expand...
Good choice. That's the one that BT suggested for my single battery. It meets all the requirements
 
flan said:
I run the 1.25 deltran and my truck didn’t run for months over the winter and it kept the batteries fully charged.
Click to expand...
If the batteries are good, most late model 1-3A chargers will keep them up. I use a 1.5A charger in conjunction with the block heater when it's really frosty out. Not to charge the batteries per se, just to keep them warm.
 
Burn'n Oil said:
If the batteries are good, most late model 1-3A chargers will keep them up. I use a 1.5A charger in conjunction with the block heater when it's really frosty out. Not to charge the batteries per se, just to keep them warm.
Click to expand...
I had an under 3 A charger on brand new AGM batteries and it failed to maintain them. In fact, over time drew them down below starting level.
 
John Jensen said:
I had an under 3 A charger on brand new AGM batteries and it failed to maintain them. In fact, over time drew them down below starting level.
Click to expand...
I would suspect a defective "new" battery or charger. I've got dual AGM boat batteries on the roll'n dog house. A 1.5A overnight charge will bring them both up to speed after they've been sitting idle for a month.
 
Burn'n Oil said:
I would suspect a defective "new" battery or charger. I've got dual AGM boat batteries on the roll'n dog house. A 1.5A overnight charge will bring them both up to speed after they've been sitting idle for a month.
Click to expand...
No, it wasn't the charger. As I said, my son had the same experience. We both sent the chargers back to the manufacturer for testing. They said the chargers were fine, get a higher amp charger. Batteries were not defective
 
You must log in or register to reply here.
Back
Top