Recommendations for 30s lipo charger

Hi, building 30s 30Ah battery, need a charger. Preferably with option to set voltage 120-126V and do currents above 2.5A (so no high power needed)

What do you recommend? Been looking at meanwell led drivers 3x42V in series but total cost for the ones i looked at will be 200 usd or so. Isn’t there a better option? It will be for home charging / indoors so doesn’t have to have IP classification.

You think a couple hundred is expensive??

Not for a high voltage like that, and certainly not for good reliability plus user adjustable voltage.

I mean yes, you can cobble together quality secondhand gear, ex-telecom / server room PSUs plus DCDC converters in series / parallel if you have the skillz.

But that is a lethal voltage there!!!

My approach would be break the pack down into modules with serial connections, reliable robust and easy to make/break.

6-8S even 10S units give lots and lots of choices in excellent balancing chargers, not too pricey even at higher amps, some can do multiple sub-packs at once.

10S getting up there more rare thus expensive, 12S forget it.

Of course if you come across a good used high-voltage charger from the EV world ($200 for an Elcon would be a steal) then normal cycling could keep your pack assembled at full voltage

and use the hobby charger for maintenance, SoH% cap testing, resistance benchmarking balancing etc.

Note that to be safe

or even to be called a "charger"

the unit should be self-terminating.

Rectifier/PSUs and DCDC converters do not do this, so you'd want to rig an HVC cutoff.

BMS is there as a safety fallback failsafe backup in case for when your primary regulation circuits fail.

Some expensive ones can control an Elcon etc with CAN commands, but you aren't paying for that level of quality if you think $200 is expensive for a good charger.

Safety first, worth spending more to not burn the house down.

I don’t see the issue with cc+cv LED drivers without charge cutoff?

When battery is at the set voltage on the driver no more current will flow. Might be some losses in the driver but the meanwells seem to be able to take it.
Might need some diodes for reverse voltage protection.. need to check this.

Battery will be protected by bms off course, at a slightly higher voltage than the driver.

It is really not a good idea for longevity's sake to keep charging past amps trailing past say 0.05C, maybe 0.02C at most, even at a reduced CV setpoint.

But yes for fire safety, so long as

your BMS is trustworthy, and

you're not just relying on one level of protection, you're probably OK.

I have a big pile of HLG-240H-54As, 50-57v about 4A each

going for $40 each plus shipping if you're interested.

I hear they are isolated, so can be serial-connected with each other, and the other voltage units in that line just fine.

The lowest current unit would apparently limit the rest, so best if the others used were also around 4A.

If you're OK with a finish capacity slightly below "vendor rating 100%"

which is better for longevity anyway

the I **believe** there is no harm in putting a 30S pack onto a charger rig putting out say 150V

So long as your adjustable HVC terminates the AC input to the PSUs when the charge-circuit / battery voltage reaches your desired setpoint.

CC-only, no holding Absorb at all.

If the current rate is over 1C, you might finish at say 5-7% below "vendor rating 100%". At slower rates, probably over 98%.

But you definitely want redundant protection there, the HVC failing could render the bank scrap and the building a smouldering pile of rubble.

This might be a good deal https://www.ebay.com/itm/164137420950

Thanks for the tip, could be good if i was in US!

with shipping to elcon 50$, shipping to me 50$ and reprogramming 100$ (yikes!), then 25% taxes and imports into sweden - then it’s a 400$ charger again - bummer

Crossthreading: https://www.endless-sphere.com/forums/viewtopic.php?t=92316

As always i’m not first :wink:

I’m looking at having three ELG-150-42AB in series, would fulfill all requirements i had at 35$ each so basically a configurable charging system at 105$, that’s not bad.

Yes ELG series not quite as good as HLG , but so long as you get adjustable versions should be fine

Good for 30s in EU

I’m looking for a simple 30s charger/supply myself. Meanwell doesn’t make searching easy

Adjustability
Cheap
High voltage
No fan
Available
Durable

Hummina Shadeeba said:

https://www.mouser.com/ProductDetail/MEAN-WELL/XLG-320-M-A?qs=Li%252BoUPsLEnsdUrofheUIGQ%3D%3D

Adjustability
Cheap
High voltage
No fan
Available
Durable

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Nice find, I might get one of those as well for my future build. Presumably they can be paralleled for faster charging?

harrisonpatm said:

Nice find, I might get one of those as well for my future build. Presumably they can be paralleled for faster charging?

Click to expand...

Don’t know. Assume so.