Bench power supply / charger - 30V vs 60V

[mondurr]

I'm putting together a 16s bank with CALB 180Ah cells and I need a charger to top balance the cells. These cheap bench supplies are all either 30V 10A or 60V 5A. The 30V 10A obviously will work fine for top balancing, but if I need to charge the assembled bank, I'll need the 60V unit, but those only do up to 5A for any voltage. I haven't purchased my inverter yet either.

Do you guys think I should just get a 30V 10A unit and worry about charging the bank later with my inverter?

 

[sunshine_eggo]

Whelp, given that cells typically arrive in the 30-50% SoC range, step #1 of balancing is to charge the 16S assembled battery using the BMS to protect it. That way, you charge very rapidly until the first cell is full. This can cut balancing time by 90%-ish.

Can you do this step with your inverter before balancing? If yes, then 30V/10A is the better choice.

 

[LakeHouse]

Do you guys think I should just get a 30V 10A unit and worry about charging the bank later with my inverter?

Yes, this makes much more sense.
The battery isn't much use to you until you get the inverter anyway. Bite the bullet and get the inverter, it'll save you soooo much time top balancing.
For that matter, depending on the quality of your cells and what BMS you have (i.e., does it have active balance capability), you be able to skip the power supply all together. Just assemble the battery with the BMS, charge it up, and let the balancer do its thing.

 

[BigGun]

Did you receive your cells yet. What was the turn around time.

 

[mondurr]

depending on the quality of your cells and what BMS you have

I bought a JBD BMS that just does passive balancing, so I assume I should definitely do a full top balance?

Did you receive your cells yet. What was the turn around time.

Yeah they came pretty quickly, 5 days after I ordered them (shipped from CA to Indiana).

 

[sunshine_eggo]

I bought a JBD BMS that just does passive balancing, so I assume I should definitely do a full top balance?

That depends on the initial charge response. You might get lucky with balanced cells. The guide lays it all out for you in explicit detail.

 

[frankrudis65]

Hi,I got a 60V,25A power supply and haven't one second complained about it...having said this my charger from the inverter isn't the most powerful and in the winter months ther's the odd occasion when I add the power supply to get a quicker charge of my 34kw banks....Frank

 

[sunshine_eggo]

Hi,I got a 60V,25A power supply and haven't one second complained about it...having said this my charger from the inverter isn't the most powerful and in the winter months ther's the odd occasion when I add the power supply to get a quicker charge of my 34kw banks....Frank

5A or 25A? If 25A, what did that run you?

The question was about the lower priced 30/10A vs. 60/5A units.

 

[frankrudis65]

5A or 25A? If 25A, what did that run you?

The question was about the lower priced 30/10A vs. 60/5A units.

I think any 5A units are a bit on the low side? I decided for an initial top charging on single cells,but I also wanted to be able to help charging the complete bank,when needed.I paid about €380.-. for a Joy-It programmable power supply... 24 OR 25A....

 

[frankrudis65]

Honestly I wouldn't know what to do with a 30Vdc power supply having to charge a 16s bank....

 

[sunshine_eggo]

I think any 5A units are a bit on the low side? I decided for an initial top charging on single cells,but I also wanted to be able to help charging the complete bank,when needed.I paid about €380.-. for a Joy-It programmable power supply... 24 OR 25A....

We're talking about $50 power supplies. Few are willing to invest your kind of scratch for just the battery build.

Honestly I wouldn't know what to do with a 30Vdc power supply having to charge a 16s bank....

If you don't already have an inverter/charger that works with 48V, you build the 16S battery and charge 8S through the BMS to cut off. Then you swap the two 8S groups and then repeat. You can then either top each cell off individually to 3.65V@10A or parallel them all and top off at 3.65V.

Once commissioned and in operation, their only use is to boost the voltage of individual cells.

 

[frankrudis65]

We're talking about $50 power supplies. Few are willing to invest your kind of scratch for just the battery build.



If you don't already have an inverter/charger that works with 48V, you build the 16S battery and charge 8S through the BMS to cut off. Then you swap the two 8S groups and then repeat. You can then either top each cell off individually to 3.65V@10A or parallel them all and top off at 3.65V.

Once commissioned and in operation, their only use is to boost the voltage of individual cells.

Yes that's true....considering though the some 20 years's lifetime of those cells,I think my humble investment of under 400 quit for a power supply is rather modest.I'ts including a laser thermometer and a resistance meter a barely 10% the total banks(2) .As I've got a straight 17s 2p under pressure,I wouldn't want to fiddle around with a 30Vdc power supply- of cause that's my case and opinion....

 

[sunshine_eggo]

Yes that's true....considering though the some 20 years's lifetime of those cells,I think my humble investment of under 400 quit for a power supply is rather modest.I'ts including a laser thermometer and a resistance meter a barely 10% the total banks(2) .As I've got a straight 17s 2p under pressure,I wouldn't want to fiddle around with a 30Vdc power supply- of cause that's my case and opinion....

For about the same price, you could get a 48V/100A charger. Most folks have an inverter/charger that is a better value UNLESS you're using the power supply for other unrelated things that make you happy. I use the crap out of my 30V/10A supply.

 

[SeaGal]

For about the same price, you could get a 48V/100A charger. Most folks have an inverter/charger that is a better value UNLESS you're using the power supply for other unrelated things that make you happy. I use the crap out of my 30V/10A supply.

... I figured that buying one of the cheap 30V/10A power supplies was better value and more current to top balance cells. Then, should I ever need to charge my finished pack with it I could just buy a $15 500W buck/boost and get virtually 60V/5A out of it... haven't needed to do that in 2.5 years though!