Will this battery tender work?

[Will_T]

I have this little battery tender linked here that I have used for a car I will soon no longer have. Is it sufficiently large to use on my 6.7? And if it is, how do I connect it with two batteries? I have seen posts saying just hook it to one of the batteries and it will keep both maintained. Others say you need two if you have two batteries. And still others say it depends on the battery tender, some can maintain two batteries and others cannot.

Does anyone know specifically if this little one I already have will work? If it is too small I will get a better one and use this for my lawn tractor. Thanks.

 

[H3LZSN1P3R]

Hook it to one battery it will do what it needs to do no issue, in the winter i have 1/2 a dozen batteries all hooked up to one maintainer in the basement it has no issue

I would look for a 2A charger the 750MA is to small unless you have the batteries unhooked from the vehicle

 

[flan]

I have this little battery tender linked here that I have used for a car I will soon no longer have. Is it sufficiently large to use on my 6.7? And if it is, how do I connect it with two batteries? I have seen posts saying just hook it to one of the batteries and it will keep both maintained. Others say you need two if you have two batteries. And still others say it depends on the battery tender, some can maintain two batteries and others cannot.

Does anyone know specifically if this little one I already have will work? If it is too small I will get a better one and use this for my lawn tractor. Thanks.

I have the supplied “hard wire” hooked up to the driver side positive terminal and the ground to the stud right on the fender by the battery. I stubbed out the connection through the grill just above the bumper. I use this one, and it does the job just fine. Same on my Kubota for several years with no problems.

https://www.amazon.com/Battery-Tender-021-0128-Maintain-Damaging/dp/B00068XCQU/ref=sr_1_3?crid=FDIH581LOZYO&keywords=Battery+tender&qid=1642034457&s=automotive&sprefix=battery+tender%2Cautomotive%2C139&sr=1-3

 

[Will_T]

Thanks! I found the two amp linked below for a better price than the 1.25 amp from Battery Tender. The 2nd link is $10.00 more than the 1.25 but is 5 amp. Is there any reason to bother getting the 5amp if it will be dedicated only to the truck?

https://amzn.to/34MTmby

Amazon.com

.

 

[H3LZSN1P3R]

I use the NOCO i prefer it over my old battery tender

 

[fuchsroehre]

I really like this here. Has been working for the truck, car and motorcycle.
Ctek charger

 

[lovegolf44]

When talked to Deltran and told them I have a 2-battery truck, they recommended this:
https://www.deltran-global.com/Batt...able-Chemistry-Weatherproof-Battery-Charger_3

Charges 3 different types of batteries. Connect the negative to the frame and the positive to the driver-side battery pos post and that'll keep both batteries charged at the same time.

 

[H3LZSN1P3R]

When talked to Deltran and told them I have a 2-battery truck, they recommended this:
https://www.deltran-global.com/Batt...able-Chemistry-Weatherproof-Battery-Charger_3

Charges 3 different types of batteries. Connect the negative to the frame and the positive to the driver-side battery pos post and that'll keep both batteries charged at the same time.

Any charger will do both at the same time when connected properly…..

 

[Will_T]

I use the NOCO i prefer it over my old battery tender

I finally got around to purchasing this2 amp NOCO. I hooked it up today and an wondering if this sounds correct. The truck has recently been driven and starts right up so no indication that the batteries are weak. When I connected it and put it in 12V mode, all seems good. The (first) 12V battery symbol lights up. However only the first red light illuminated. NOCO manual says this indicates that the batteries are at 25%. Seems like since they have been working fine, they would start out at more than 25%? It has been a couple of hours now and still only the 25% charged light is on. Should I have gotten the 5amp charger, or even the 10 amp instead of this one? OR does it make sense that the batteries may really be at 25% and it will just take a long time to move up?

edit: LOL. I went back out to check again right after posting this and now the 2nd light is pulsing so that indicates that it has moved from 25% to somewhere between 25 and 50%. Once the 2nd light is solid then they are at 50%. So charging is taking place I guess. Looked at my watch and it has been exactly 3 hours now so I maybe they really did start out at only 25%, (very surprised). Need to be patient, I guess. Still would be interested in anyone's experience. Does it make sense that batteries that seem to be working great would only be at 25%?

 

[Rockcrawlindude]

I have two 3A (battery tender) brand for my older vehicles. I also have a HF brand that has a charge meter. Battery chargers sometimes will show a low charge for a while and then just jump to full charge and then maintain.

I have No experience with dual batteries.

 

[H3LZSN1P3R]

I finally got around to purchasing this2 amp NOCO. I hooked it up today and an wondering if this sounds correct. The truck has recently been driven and starts right up so no indication that the batteries are weak. When I connected it and put it in 12V mode, all seems good. The (first) 12V battery symbol lights up. However only the first red light illuminated. NOCO manual says this indicates that the batteries are at 25%. Seems like since they have been working fine, they would start out at more than 25%? It has been a couple of hours now and still only the 25% charged light is on. Should I have gotten the 5amp charger, or even the 10 amp instead of this one? OR does it make sense that the batteries may really be at 25% and it will just take a long time to move up?

edit: LOL. I went back out to check again right after posting this and now the 2nd light is pulsing so that indicates that it has moved from 25% to somewhere between 25 and 50%. Once the 2nd light is solid then they are at 50%. So charging is taking place I guess. Looked at my watch and it has been exactly 3 hours now so I maybe they really did start out at only 25%, (very surprised). Need to be patient, I guess. Still would be interested in anyone's experience. Does it make sense that batteries that seem to be working great would only be at 25%?

See battery % does not work as you would think it does its not a true linear progression my maintainers say the same for the first while then it will jump right up also. Don't read in to the progress bar to much it will have you scratching your head lol


During the winter i typically have 8 batteries all tied together on one 1A maintainer in the basement no issues it usually takes 1-2 days for the charge indicator to reach 100%

 

[MEGA HO]

From electrical point of view, dual batteries connected in parallel are treated as one large capacity battery. 2 batteries connected in series are treated as one higher voltage battery. Charger will only see one battery. Just like in laptops, power tools and electric cars there are banks of smaller cells connected in series and parallel and the whole thing is treated as one large battery.
Connecting 2 smart chargers/maintainers to dual batteries (one charger to each battery) may screw things up as chargers would interfere with each other. Unless batteries are disconnected then you'd need 2 separate chargers.
2A charger will work but will take a long time to charge, maybe fine for maintaining though.

 

[H3LZSN1P3R]

From electrical point of view, dual batteries connected in parallel are treated as one large capacity battery. 2 batteries connected in series are treated as one higher voltage battery. Charger will only see one battery. Just like in laptops, power tools and electric cars there are banks of smaller cells connected in series and parallel and the whole thing is treated as one large battery.
Connecting 2 smart chargers/maintainers to dual batteries (one charger to each battery) may screw things up as chargers would interfere with each other.
2A charger will work but will take a long time to charge, maybe fine for maintaining though.

A fully flat battery will take less than 24hrs on avg to be fully charged with 2A a newer vehicle when off only uses .08A so any maintainer .750A and up is plenty to keep the vehicle charged up

 

[MEGA HO]

A fully flat battery will take less than 24hrs on avg to be fully charged with 2A a newer vehicle when off only uses .08A so any maintainer .750A and up is plenty to keep the vehicle charged up

Yup 24hrs is a long time, relatively speaking, lol. I have 3 CTEK smart chargers/maintainers, 2 on my bikes and one I throw from one vehicle to the other depending which one I use (I don't drive my truck in winter time).

This one is 0.8 / 4.3A charger if I set it at 0.8A it will take forever to charge a flat battery.

For maintaining anything should work, depends on a load when off. my both vehicles have dash cams rolling 24/7 (parking mode) even when off so my draw maybe a little higher, didn't try to measure it.

 

[H3LZSN1P3R]

Yup 24hrs is a long time, relatively speaking, lol. I have 3 CTEK smart chargers/maintainers, 2 on my bikes and one I throw from one vehicle to the other depending which one I use (I don't drive my truck in winter time).
View attachment 46912
This one is 0.8 / 4.3A charger if I set it at 0.8A it will take forever to charge a flat battery.

For maintaining anything should work, depends on a load when off. my both vehicles have dash cams rolling 24/7 (parking mode) even when off so my draw maybe a little higher, didn't try to measure it.

I have always been one to just pull all my batteries out and use one maintainer come winter.

Those old CTEK maintainers were great when crappy tire had em on sale i had a couple of em years ago

 

[AH64ID]

Another vote for NOCO. Unlike many tenders they stop charging once the battery is 100% and resume charging when the voltage drops. This is better for the battery.

It will take more than 24 hours to completely recharge dead batteries in these trucks with a 2A charger thou. Even the lowest rated Group 65 batteries have ~60AH, which means a pair of batteries that are at 50% SOC (12.1V) would take 30 hours with a 2A charger in a perfect world, but there are inefficiencies and as the battery passes 80% SOC the charge rate really slows down. I would expect a 2A charger to take 72 hours to get a pair of G65’s back to 100% SOC. If they were low enough to not start the truck it could take double that time.

While a bigger bank here is what it takes to recharge my 5th wheel. 300AH battery bank with a 55A charger. If the batteries are at 50% SOC they will take roughly 36 hours to get to 100% SOC. The first 4 hours get them to roughly 90% SOC and then it takes another 24-36 to get to 100%. It just takes time to top them off, not much you can do about that with traditional battery styles.

 

[Will_T]

See battery % does not work as you would think it does its not a true linear progression my maintainers say the same for the first while then it will jump right up also. Don't read in to the progress bar to much it will have you scratching your head lol

Yes it is working OK. The first time it took many hours, (overnight), to get to what the LEDs show as 1/2 to 3/4 full, but then by the end of that day, it was up to the pulsing green light. When I checked again the next morning, the green light was solid, so all is good. Just for fun, I unplugged it once I saw the solid green light, then plugged it right back in. It started charging and showing only 1/4 full! But within 15 minutes it worked its way back up 75% then several hours later when I looked again it was solid green. I was scratching my head a bit though wondering why when I plugged it back it, it did not immediately show the same as when I had just unplugged it. Guess it has to go through the cycle to make sure all is well.

Now at least, if the truck is sitting for a week or two, when I go to start it, the grid heater won't pull down the batteries to where it won't start. That is what happened a couple of times. I unhooked the grid heater a couple months ago so as to not harm the batteries if I forgot to start it once a week. With the grid heater unhooked, I no longer had any trouble starting it even after a couple of weeks of sitting. With the NOCO I can hook the grid heater back up and not worry about it. Thanks!