# Best power supply for 200ah gbs3



## evmetro (Apr 9, 2012)

I am getting ready to do initial charge on 34 gbs gen 3 200ah cells. I have the orion bms, but it is not installed yet. I have been reading about parallel or individual initial charge via an adjustable dc power supply on these forums, but can't seem to find what exactly I will need for these specific cells. Can I get some input on best power supply and/or procedure to apply to these cells prior to hooking them up? Thanks. If it helps any, they will be running an hpevs ac 35 kit, and managed with an orion bms.


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## evmetro (Apr 9, 2012)

I picked up a 30 volt 3 amp max power supply last night. I also have an automatic lead charger that I am considering using to speed up the process. Groups of four in series and my lead charger should shut down just before each cell reaches 3.46 volts. Then finish one at a time with the power supply.


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## Ziggythewiz (May 16, 2010)

I spent the weekend charging come cells with a 12V charger. On the 10A setting it cuts off at 14.2V, where I was shooting for 14.6. I think the 2A setting will go higher, so I'll try that once I finish my busbars for a 4S10P final charge before paralleling.

I have a JLD404 that monitors the charge, but it's relay never tripped because the lead cutoff was lower.


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## evmetro (Apr 9, 2012)

Having trouble getting anything out of my power supply. I picked up a ps3003u power supply, and have 3.6 dialed onto the volts screen, and cv indicater is lit. My multimeter does not show anything. When I mess with the current knobs nothing happens unless I turn them all the way down, at which time the indicater moves from cv to cc. Can anybody give some pointers to get this thing operational?


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## Ziggythewiz (May 16, 2010)

Is it hooked to a battery?


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## evmetro (Apr 9, 2012)

Nevermind. I had picked up brand new fluke leads with my power supply, and I have it narrowed down to a bad black lead. I borrowed a lead from another tech and it is working now. 3.6 still dialed in on the volts side, but cv led is out and the cc light is lit. 3.25 on the amps screen. Does this sound right?


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## Ziggythewiz (May 16, 2010)

Yeah, it should do CC until it reaches the set voltage, then switch to CV.


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## evmetro (Apr 9, 2012)

Thanks ziggy. I guess I can walk away from it for a while.. "a watched pot never boils.." Can this be left unattended over night?


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## Ziggythewiz (May 16, 2010)

I would never leave something you haven't used lots unattended overnight. 3.4VPC is the safe float voltage, so I wouldn't be far from it when it's over that.


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## evmetro (Apr 9, 2012)

Ok, I think I have it. I will keep a pretty good watch over it until I go home and turn it off. If it was not up to 3.6, I will pick up where I left off in the morning. Hypotheticaly, could I tune my volts to 3.4 and leave it overnight if I was ready to start the next four pack? Then in morning turn it up to 3.6 and babysit it the rest of the way?


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## frodus (Apr 12, 2008)

Just to clarify....
Set the voltage when the power supply is disconnected. i.e. take the leads off, set to the voltage you want, connect then dial in the current you want. DO NOT TOUCH the voltage.

You don't want to set the voltage while it's connected, because you're actually setting it to a higher voltage than you think. You're setting the "I want to pull the batteries to this voltage". The voltage on the displace of the power supply is the voltage at the terminals..... and the batteries are pulling the PS voltage lower, while supplying the current you set.


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## evmetro (Apr 9, 2012)

I think this is going to take awhile. My battery terminals started at 3.32 and have only moved up to 3.34 after all these hours...


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## frodus (Apr 12, 2008)

Of course it will!

You've paralleled all 34 of those 200Ah cells. You have a 3A power supply charging a 3.2V 6800Ah battery.

Lets say they're all at ~75% SOC, that would mean you need to put 1700Ah into them. With a max charge current of 3A per hour, you're looking at about ~566 hours if you're at 75% SOC to get them all top balanced. That's about 2 full weeks.

It could be longer if they were shipped with 50% SOC and will take twice that amount of time. If they have 90% SOC, you might balance them in ~9 days.

Your power supply, is a bit small to balance them as quickly. It's going to take a long time with only 3A. Either have patience, or get a bigger supply that can charge at a higher current. A 20A charger would balance a 75% SOC pack in about 3.5 days, a 50% SOC pack in about 7 days and a 90% SOC pack in about 1.5 days.


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## evmetro (Apr 9, 2012)

Wow! Can you put more than 1the power supply into the mix? The local frys electronics store only has these in 3 amp units in stock. I suppose I could get a bigger unit from the internet and after waiting for shipping, I could still top balance these guys quicker than this little guy can.


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## frodus (Apr 12, 2008)

Depends, some can, some cannot parallel. 

Where do you live?


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## Ziggythewiz (May 16, 2010)

Even if the power supplies can't parallel, you can just break the cells into groups and charge them faster that way, then stick them all together again near the end.


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## frodus (Apr 12, 2008)

That's a good idea. If you can only get 3A power supplies, then just use 2 or 3 of them and break the pack up. It'll half or 1/3rd your time.


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## evmetro (Apr 9, 2012)

I found a volteq 15 volt 50 amp unit online for 289 bucks. Does this sound like an appropriate power supply?


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## Ziggythewiz (May 16, 2010)

If it's fully adjustable and properly monitored it should be fine.


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## frodus (Apr 12, 2008)

Is it a linear power supply? Is it adjustable for current and voltage?

50A would do a 50% charge in under 3 days, 25% in a day and a half and a 10% in a half a day.


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## evmetro (Apr 9, 2012)

I don't believe it is linear. I think it is switching, and fully adjustable. Should be here tomorrow. Model volteq hy1550ex.


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## frodus (Apr 12, 2008)

That's a great supply. I own a Mastech myself (dual 10A 30V model). Perfect for what you need it for.


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