multiple chargers for a single battery?

[aethyr]

I've seen a single chargers charging multiple batteries in parallel...but can you use multiple to chargers to charge a single battery faster?

For example, if I have 2x250W chargers, but I only use one of them to charge a pack. Can I wire my chargers in parallel to give 2x current into a single pack?

 

[mattjrogers]

I would like to know the very same thing. I have two 58.4v lifepo4 charges - one 5 amp, the other 3 amp. The only issue that I could see is if they fight each other at the end of charge as they each sense cuttoff voltage and shutdown at different points or keep turning back on and off because of the other charger's input.

 

[Sunder]

The quick answer is "yes".

The complicated answer is that if you have any doubts about the provenance of the charger, you might want to put a diode on each charger, to prevent reverse flow if one charger gets to a higher voltage than the other. (This would damage the charger if the battery voltage was higher than the charger voltage anyway, so this is an unlikely situation)

 

[amberwolf]

If the chargers are really identical and well-designed, then yes you can parallel them and they will share current and charge correctly.

I use some Meanwell HLG's that way.

But not all chargers or PSUs share well, and there have been occasional reports of dead chargers after connecting them in parallel (though the exact failures are not known, and might be unrelated to that, but probably were caused by it).

 

[DrkAngel]

Multiple chargers in parallel can work just fine.

7s12p - 25.9V 31.2Ah 29.4V @ 4.20V iMax Balances @ 29.19V (4.17V)

I varied between a 10A bulk charger and a 3A balance charger, until ...
Decided to set bulk charger to 28.8V, isolate with a diode and run parallel with balance charger @ 29.2V.
(Diode prevents any higher voltage "backwash" into the bulk charger.)
Effectively shuts off the bulk charger as accepted charge reduces to the balance chargers reduced capability.
Gave me the benefits a 13A bulk charger and, effectively, a 13A balance charger.
(Balance only occurs in the last fraction of charging Amp.)

Accepted charge amps reduces to near zero as selected voltage is attained.
Setting one, of multiple chargers, to lower voltage does not increase charge time.

 

[The Battery Doctor]

My answer is NO. The battery and charger are connected as one unit and they communicate with each other so THAT makes it possible to keep charging CC when the charger need to change to CV and therefor overcharging and damaging the cells! The current vill have nowhere to go and therefor create heat, excessive heat!!

Well technically you can charge it but the result is NOT what you are looking for. The questions sounds a little like "if i drive two cars at the same time, will i get there faster" to me. Hope you get the point.

 

[amberwolf]

Most batteries and chargers do *not* communicate with each other (at least in the ebike world).

They are "dumb" chargers in that respect, in that the charger does whatever it does, and the battery does whatever it does, and each responds to the other's actions or reactions independently--they don't "work together" in a coordinated fashion.


So as stated here:
https://endless-sphere.com/forums/viewtopic.php?p=1284986#p1284986
it depends on the chargers themselves, on their design and similarity.

If you were to grab two random chargers and hook them up at the same time, then the results would probably not be what you were after. It could still be made to work in some situations, but it would require re-engineering one or more of the chargers to do it.



As for the car analogy, then there are situations in which driving two at the same time *would* get you there faster: wherever the single car could not carry the load at the desired speed, but two of them together could. (for instance, if there simply werent' enough HP to get one car plus it's load up a hill very quickly, but the car by itself could do so easily and quickly, then simply adding a second car would fix that). If the cars were not self-driving/following (properly designed charger analogy) then it would take redesigning/kludging a single control mechanism for both of them to be used by a single driver, but it would still work.

A "better" (simpler) solution would be to use a single more-capable car (or charger) but it does not mean that the multiple-car (or charger) solution can't work just fine.