PC Power supply to charge 18650

[marce002]

Hello All...

Please do not offend me I Im wrong with this, and a balance charging method is a must.! ha
I have a PSU from old IBM server, (ASTEC AA20790), wich outputs 12V 14A , I wonder if I can charge an array of 3 cells 18650 in series & parallel: (4,2v*3 = 12.6v a row), and doing 14 rows of 3 ..... asuming Im charging at 300mah each cell....and current is limited by the array of 14 rows of 3 in series.... is that ok if I supervise all the charge? or is a recipe to problems?

14 x 3 = 42 cells

 

[dogman dan]

The output is rated 12v, but to fully charge 3s of cells that charge to 4.2v, you need 12.6v. check with a voltmeter what the actual output is.

It would not be good to use it, if it's higher than 12.6v output. But it will make a great power supply for a 12v powered RC charger.

Likely it does have a screw to tweak output voltage.

 

[marce002]

thanks a lot also i would like to state this, from other post:

These PSU's are usually group-regulated, which means they cannot handle crossloads well. They lower V to 10V when more than 4A are used in the 12V line, The goal is to mod the PSU in order to obtain tight +12V regulation without requiring any dummy load on +5V.

 

[marce002]

Hi I've bought a 36v 350W used hub motor kit... no charger , but I got a lipo bottle 36v!!! that seems to have proper cels volts, 3,7V x 10 cells..... My question is can I charge the lipo 10s inside the bottle with the bottle BMS using a 12v 18A PSU?? (I do not have PSU of power supply of more power or V)... if cannot, will need to buy a Icharger 1010b capable of charging 10s with input power from 12 to 18 right?

 

[Jon NCal]

No, just get an inexpensive 36V charger, such as one from lunacycle.com:
http://lunacycle.com/batteries/chargers/36v-2amp-charger-for-sondors-and-other-36v-bottle-packs/

 

[marce002]

Right, I'm in a hurry, and can't wait 20 days to come ..... so i would like to pick something I have locally,,,, I have

2 power source 12V 18A each ASTEC
1 HP 18.5V 3.5A
or
1 IBM 16V 4.5A


can I connect in series the first 3 items, with a total of 42,5V (12v+12v+18.5V) leaving one earth connected ?

 

[spdas]

You certainly can use the charger rigging that you described, but since you are in a hurry, you might want to order a new bottle battery now, so when you ruin your Lithium with your charger setup, you won't waste any time getting back on the the road.

Francis