Bench power supply for direct charging?

[buzzfirst]

I have several different configurations of konion, lifepo4 and nicad batteries. I have never owned a bench power supply and was wondering what would happen if I used it for a charger say for 10 lifepo4 cells. Say I set the voltage to 36.5 and the amps to one amp for instance(once the pack was well balanced). What would happen when the battery was fully charged? Would the supply see the 36.5 volts and reduce the current to zero(I think this is how it would operate but could be totally wrong). I am trying to buy a one solution charger for my present and future setups. I am aware that bulk charging other types of lipo is a no no! Charging speed is not an issue. I could bulk charge and every so often use the same supply to charge individual cells for balancing. Am I on the right track.

 

[liveforphysics]

Yes. That's exactly how it works. You can only continue to charge while a voltage difference exists, so as the pack nears the voltage of the power supply, current approaches zero, and it's can't overcharge even if it's left on the charger with the power supply on indefinitely.

Virtually every electric race team using large packs charges with power supplies rather than "chargers". The only thing I personally use a "charger" for these days is when I want to fly/drive my RC vehicles. Everything else is charged on a bench power supply.

 

[buzzfirst]

Thanks for the quick reply, now to find that bench supply.

 

[IRON DOG]

Yes. That's exactly how it works. You can only continue to charge while a voltage difference exists, so as the pack nears the voltage of the power supply, current approaches zero, and it's can't overcharge even if it's left on the charger with the power supply on indefinitely.

Can somebody tel me what apening technicaly ???

I got a headway pack maid of 24 series 2 parallel (a38120se) lifepo4 cells .

Yesterday , i got my new adjustable charger , its a Mastech dc powersupply HY10010EX .

I put the charger on the pack whitout the BMS at 87.6 volts ( 3.65 v for 24 series ) .

The charge was looking good , start at 6.5 amp and slowly going down .

6 amps , 5 , 4 ..... 1.5 and then noise " tock , tock " comming from the pack

Unplugged the charger right away and check all my cells .... OH NOOOO .

4 of them are f..k , i check the voltage on those ( 0.597 v )( 0.274 v )( 0.004 v )( 0.001 v )

I try to charge them individually , nothing work still the same , I gess i overcharge them

I try to charge the pack whit the BMS , the charger wont start .

 

[parabellum]

I put the charger on the pack whitout the BMS at 87.6 volts ( 3.65 v for 24 series ) .

The charge was looking good , start at 6.5 amp and slowly going down .

6 amps , 5 , 4 ..... 1.5 and then noise " tock , tock " comming from the pack

Unplugged the charger right away and check all my cells .... OH NOOOO .

4 of them are f..k , i check the voltage on those ( 0.597 v )( 0.274 v )( 0.004 v )( 0.001 v )

I try to charge them individually , nothing work still the same , I gess i overcharge them

I try to charge the pack whit the BMS , the charger wont start .

You should have top balanced the pack first, before bulk charging. You lost 4 cells now, sorry to read that.