monster server psu charger ~4kw

knighty

10 kW
Joined
Sep 13, 2012
Messages
535
I bought these ages ago to make a charger with but I've had too much to do.... one broken bmsbattery.com charger later and I've pushed these up to the front of the queue




7 x 12v 41amp dell server PSUs
1 x 5v 60amp meanwell
(for 24s)

plan is to isolate them all, then hook them all up in series and use the meanwell for voltage adjustment and current limiting

will need to mount voltage and current displays so I know what's going on, by the look of it I should be able to mount them into the top or end of the meanwell case, need to take it apart to check for clearance first

only running a 10ah pack right now, but I've got two new box frames being laser cut and cnc folded next week, once they're built up I'll be putting 50ah on each bike
(might be split into 2 packs, will have to see how will it fits/what access is like)

once I get this up and running.... I'll get another 5v meanwell and connect it in series to the server PSUs too, so I can charge 2 bikes independently but at the same time (with 1 meanwell each) I'd have got the 2nd meanwell straight away, but I wasn't planning on 2 bikes when I bought all this months ago

running a BMS on each bike, end of charge might be a bit slow, but I normally charge overnight anyway - I might stick fast/slow charge switches on the meanwells to switch between say 5amps and 18amps charge - I charge overnight most of the time but sometimes need to charge faster

wish me luck :)
 
Good luck, but you might be interested in my current limiter for these supplies.

I'm waiting on some bits, but it uses the internal shunt of the power supply (which of course had to be on the high side didn't it, so I need a differential shunt amplifier - sigh). Its designed for limiting the current of each power supply to 50A (or less, depending on your resistor selection).

One board does two supplies, but they can be daisy-chained to suit many supplies in series.
 
I've been watching your thread ;)

I'll just use the meanwell for now, but I'm switching from 24s lifepo4 to 24s lithium ion so I'll need to re-jig my chargers a bit then and will check your thread out again ;)
 
I've just recieved the TSC101B highside shunt amplifiers from far(ke)nell and am waiting on the PCB positive photoresist boards to turn up, then will actually be able to build something...

Waiting waiting...
 
just a quite notice in case anyone else reads this.... before you go buying server power supplies, make sure you can pull enough power out of the wall for them

bit easier in the UK with 240v mains voltage compared to some other places

I've got a 32amp 240v socket in the garage ready for them ;)
 
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