power supply question

[dukesy]

If i have a pro peak 13.8v 0-20amp output power supply how many chargers should i be able to run off of it. Ive got a cellpro 4s and two E-station 301 DX's.

So far its been fine running the cellpro and one of the 301's could i use all three together :dontknow
The biggest packs im charging are 3300mah 11.1v and im using Flightpower v - balancers on the 301's

[Pinecone]

At 1C, you are going to take about 3.3 - 4 amps per charger.

So you should be able to run all three with that power supply.

The problem will come if you go to 4S or high packs as the amp draw picks up to upconvert the voltage.

[dukesy]

Thanks Pinecone
Im using the cellpro on the 1.4c setting and the 301's on 2c with the flightpower v balancers. If charging at 1c is roughly pulling 4amps would 2c be 8amps :dontknow

I have no plans of using bigger packs untill the trex 500 comes out or find some money to get a 600 :mrgreen:

[Pinecone]

That will be close enough to figure.

3300 mAH 3 S packs (approximate):

1C = 3.4 - 4 amps from PS
1.4C = 4.7 - 5.5 amps
2C = 7 - 8 amps or so

So in your setup you are looking at 15.4 - 21.5 amps depending on efficiencies. So I would say you will be fine. If you draw too much, the PS voltage normally drops, so put a voltmeter on it and the voltage drops more than 1 volt, I would cut on charger rate back.

[dukesy]

Thanks again pinecone

The cellpro is just gona be charging our smaller packs up to 2170mah so it shouldnt pull so many amps. I'll give all 3 a go next time i charge and see what happens :dontknow i suppose the worst is blowing the fuse in the power supply.

Got plenty of time to charge lipo's this time of year :roll:

[Pinecone]

Actually I watched my TP1010C yesterday and it drew 2.1 amps at peak charging a 3S 2100 pack at 2.0 amps. And that was only from about 12.4 volts to 12.6 volts at 2 amps, then by the time it dropped back to 1.8 amps at 12.6 volts, it was back to 2.0 amps and then kept dropping.

So I would revise my estimate to a max of 3.5 amps for 1C on 3300 3S pack with the power supply putting out 13.8 volts. So yoru setup woudl draw only 3.5 x 2 per pack or 7 amps x 2 plus 1.4 x 3.5 = 18.6 amps and only for a short period if all three chargers ended up in the peak amp draw range at the same time.

[dukesy]

Sweet cheers again for all the info :thumbup:
Just got to fix my trex so i can run some batteries out :arggg: