Charge two lithium batteries from one dcdc charger
Brianvicki said
07:42 PM Mar 1, 2025
Just wondering if there is a way to charge firstly, from. 25amp DCDC Charger, a 100amp lithium, when thats a 100% charged, go to a 50amp lithium. Maybe via a VSR
I currently have the 50 amp slim lithium, but will be replacing it with the 100amp slim lithium, but wouldnt mind keeping to 50 as a back up and just keep it charged up in case.
Peter_n_Margaret said
07:56 PM Mar 1, 2025
Connect the 2 batteries in series and you will have one 150Ah battery.
Cheers,
Peter
Brianvicki said
08:15 PM Mar 1, 2025
thanks
dont they have to be very similar type batteries, the 50amp is about 4 years old and the 100amp will be brand new
both iTechworld slim batteries
Are We Lost said
08:15 PM Mar 1, 2025
Presumably you mean to connect in parallel to retain a 12 volt supply.
Peter_n_Margaret said
10:14 PM Mar 1, 2025
Are We Lost wrote:
Presumably you mean to connect in parallel to retain a 12 volt supply.
Oops............Correct................
They are very "similar" and the age difference should not be any concern.
For the health of both, better to share the work over the 2 rather than one used and one left fully charged (which is not best practice for Li).
It is also cheaper than adding a VSR.
Cheers,
Peter
Cupie said
11:10 AM Mar 2, 2025
Are We Lost wrote:
Presumably you mean to connect in parallel to retain a 12 volt supply.
Was just about to say the same
Scubadoo said
11:13 AM Mar 2, 2025
I agree. Just parallel the batteries.
Our setup has a now 11 year old 300Ah and 2 year old 280Ah LiFePO4 batteries permanently paralleled.
Both follow SOC within 1 or 2%. No issues so far and I don't expect any.
Brianvicki said
11:56 AM Mar 2, 2025
Thanks everyone, instead of buying the 100amp lithium slim, I might just buy another 50amp slim lithium, a cheaper option as 100amp in the car is enough
And then just run 2x50amp lithiums in parallel
Dick0 said
03:21 PM Mar 2, 2025
You could use a 12V dual VSR connected between the 100AH and the 50AH batteries.
Cost of VSR about $26.00.
Peter_n_Margaret said
05:57 PM Mar 2, 2025
Better for the batteries if you cycle them both together in parallel.
Cheers,
Peter
Brianvicki said
07:01 PM Mar 2, 2025
The iTechworld slim batteries dont have normal battery terminals.. each has Anderson plugs, which makes it easy to go with one cable and connectors from one to the other one.
When I look at the diagrams, it mentions to run the positive from battery and the earth from the other is that really necessary and does it really matter which battery I run the loads from.my thought is it wouldnt matter and that I can use the Anderson plug lead from one to the other for the parallel..
TimTim said
10:28 AM Mar 6, 2025
Brianvicki wrote:
The iTechworld slim batteries dont have normal battery terminals.. each has Anderson plugs, which makes it easy to go with one cable and connectors from one to the other one.
When I look at the diagrams, it mentions to run the positive from battery and the earth from the other is that really necessary and does it really matter which battery I run the loads from.my thought is it wouldnt matter and that I can use the Anderson plug lead from one to the other for the parallel..
Simple solution.
As above, connect one battery to the other using an Anderson connector as you have stated. Buy yourself a a 2 into 1 Anderson connector as in the photo below. Remove either the positive or negative cable out of the single end of the 2 to 1 and insert it into anther Anderson connector. The two Anderson connectors with only one terminal connector then go into the two batteries.
The easiest way I have found to remove the connected pins from the connector is to place the connector on a solid ground surface, stand on the connector and then with a fine screwdriver press down on the retention spring tab and pull on the cable with your other hand. The terminal will move back far enough to be released by the pin but then sometimes will not fully come out. Simply pick it up and give it a tug to pull it apart.
-- Edited by TimTim on Thursday 6th of March 2025 10:29:24 AM
-- Edited by TimTim on Thursday 6th of March 2025 10:38:45 AM
Just wondering if there is a way to charge firstly, from. 25amp DCDC Charger, a 100amp lithium, when thats a 100% charged, go to a 50amp lithium. Maybe via a VSR
I currently have the 50 amp slim lithium, but will be replacing it with the 100amp slim lithium, but wouldnt mind keeping to 50 as a back up and just keep it charged up in case.
Cheers,
Peter
thanks
dont they have to be very similar type batteries, the 50amp is about 4 years old and the 100amp will be brand new
both iTechworld slim batteries
Oops............Correct................
They are very "similar" and the age difference should not be any concern.
For the health of both, better to share the work over the 2 rather than one used and one left fully charged (which is not best practice for Li).
It is also cheaper than adding a VSR.
Cheers,
Peter
Was just about to say the same
Our setup has a now 11 year old 300Ah and 2 year old 280Ah LiFePO4 batteries permanently paralleled.
Both follow SOC within 1 or 2%. No issues so far and I don't expect any.
And then just run 2x50amp lithiums in parallel
You could use a 12V dual VSR connected between the 100AH and the 50AH batteries.
Cost of VSR about $26.00.
Cheers,
Peter
When I look at the diagrams, it mentions to run the positive from battery and the earth from the other is that really necessary and does it really matter which battery I run the loads from.my thought is it wouldnt matter and that I can use the Anderson plug lead from one to the other for the parallel..
Simple solution.
As above, connect one battery to the other using an Anderson connector as you have stated. Buy yourself a a 2 into 1 Anderson connector as in the photo below. Remove either the positive or negative cable out of the single end of the 2 to 1 and insert it into anther Anderson connector. The two Anderson connectors with only one terminal connector then go into the two batteries.
The easiest way I have found to remove the connected pins from the connector is to place the connector on a solid ground surface, stand on the connector and then with a fine screwdriver press down on the retention spring tab and pull on the cable with your other hand. The terminal will move back far enough to be released by the pin but then sometimes will not fully come out. Simply pick it up and give it a tug to pull it apart.
-- Edited by TimTim on Thursday 6th of March 2025 10:29:24 AM
-- Edited by TimTim on Thursday 6th of March 2025 10:38:45 AM