Ampster
Renewable Energy Hobbyist
With a used pack your actual settings will probably be detetermined by the cells that are going to be runners at the top and bottom. They will determine your usable capacity. It may be one cell or two.
Big Battery 24v A123
- Thread starter MrNatural22
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solarbat73
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gonna use your pin out to connect my bms.
thanks!
MrNatural22
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These A123 24v batteries are supposed to be new never used. That's what Bigbattery is listing these as.........
Looks like they are now out of stock
Ampster
Renewable Energy Hobbyist
I stand corrected. I jumped into the middle of the thread where the OP was trying to determine the capacity without having any context. . However they did not come through the retail channel so they must have been somewhere for some time for some reason and stored at some unknown SOC. Those are "some" of the unknowns that may result in some variation of capacity.
I will read the entire thread to get a better perspective.
MrNatural22
?SW sunshine =⚡️⚡️lit up thru the darkness✌️
Your likely right on that I assume these are old/new stock that were never put into use and have sat for a while. They seem to be shipped at 50-60% and all the cells were close when received. I also had one cell that dropped quickly at the lower knee and my capacity was less that stated in the beginning by 20% BB refunded the 20% after communications and several capacity test cycles. But, over use it has improved some after running a few more cycles and capacity is now only <5%> less. so I'm pleased with its ability. I bought a second one that has performed above rated capacity from the beginning and has no issues.
I am the OP on this long and winding thread and there's been a lot of learning and advise form many on the A123 ✌
I am the OP on this long and winding thread and there's been a lot of learning and advise form many on the A123 ✌
MrNatural22
?SW sunshine =⚡️⚡️lit up thru the darkness✌️
Sounds like it could be a bad idea for these cells?
May substantially shorten battery life.
May substantially shorten battery life.
MrNatural22
?SW sunshine =⚡️⚡️lit up thru the darkness✌️
@rcfortune There are many options for under $200. I personally use a 30v10a switched PSU for my back up shore charger @ around $60 it has served me well plus it has many other uses. or Victron makes an adjustable smart charger for a little more than you paid for the BB one. Under $200 and has BT.
Ampster
Renewable Energy Hobbyist
I have so many power supplies of various voltages and Amperages I just want to get some utility out of them. I did buy the buck converter that @GXMnow recommended and it works for a lot of various charging applications. I have given up on the ones with knobs and displays since I have burned through at least 3 of those in 8 years. I have done the same with power supplies from Meanwell and chinese no name clones. It has become a hobby with a fixed expense.
John Frum
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link please.
Ampster
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GXMnow
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Yup, that is the one I got.
I have only run it up to about 5 amps so far. It has not gotten warm enough to even turn the fan on. I have used it to charge an old digital camera battery and test some LED light strips. The CC CV changeover is very sharp, it does not start dropping current until the voltage at the output terminals was within about 0.02 volts of the set voltage. I do need to get a case for it though. The open board will certainly be creepy when I use it off my 57 volt battery bank.
I have only run it up to about 5 amps so far. It has not gotten warm enough to even turn the fan on. I have used it to charge an old digital camera battery and test some LED light strips. The CC CV changeover is very sharp, it does not start dropping current until the voltage at the output terminals was within about 0.02 volts of the set voltage. I do need to get a case for it though. The open board will certainly be creepy when I use it off my 57 volt battery bank.
Ampster
Renewable Energy Hobbyist
It has a good input range of 10 to 60 volts and I will have to add a small Anderson connector to my pack so I can use that as a source. Since it is a buck converter using it off the pack means the Amps drawn from the pack will be smaller at that voltage but I would prefer a case also. There is always the big shrink wrap that the ebike guys use for their packs.
It says it has a capacity of 10 Amps but I never took it past 5 either. I did use it to charge some Nissan Leaf modules which I am getting ready to sell. The cut over from CC to CV is easy to see because of the LEDs. I was looking at the Riden but it would not get me much more capacity. I would like to find a model that does 20 to 30 Amps but I am sure it is much more pricey. That need is only for the next month until I get the Nissan Leaf modules tested and sorted. It would take that long to get one from China.
It says it has a capacity of 10 Amps but I never took it past 5 either. I did use it to charge some Nissan Leaf modules which I am getting ready to sell. The cut over from CC to CV is easy to see because of the LEDs. I was looking at the Riden but it would not get me much more capacity. I would like to find a model that does 20 to 30 Amps but I am sure it is much more pricey. That need is only for the next month until I get the Nissan Leaf modules tested and sorted. It would take that long to get one from China.
GXMnow
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I think these would work fine to parallel 2 or even 3 of them to share the current. The negative side is common from input to output. It is nice to be common ground on DC testing. I have not tried to set it for output higher than input, it will probably go stupid. It can only drop lower than input as a buck converter. They have an even higher power Boost converter, but it can only step up to a higher voltage than input. The Buck/Boost that can go either way is lower power and only a few could take the 60 volts in.
Ampster
Renewable Energy Hobbyist
I know when I was initially using inexpensive Mean Well power supplies to charge my EV conversion I needed to make sure they were isolated on the AC side. They were in series on the DC side. What are the issues paralleling them? I have a 48 volt 30 Amp Mean Well left over and it would be perfect if I could use that Meanwell and some of these to put 20 Amps into some things. I would still run them at 60 to 70 percent of capacity to not stress them.
John Frum
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Why on the AC side?
GXMnow
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That should work just fine. When they are in Constant Current mode, they will each supply their set current and they should add up nicely. When they hit the Constant Voltage point, any imbalance might cause one to take more of the load, but it will still never take more than the CC setting, so I don't think it will be a problem. If the voltage is off too much, you can balance each one into a small load and check them with a meter. If one has to be set 0.02 volts higher to get the same output, it is no big deal. For $30 it seems like a great little test power supply.
John Frum
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I've not had much luck from drok buck and/or boost converters.
Better the 50% have failed.
Just had one go dead short on the input side.
Ampster
Renewable Energy Hobbyist
It was 8 years ago and I may not remember correctly. They were in parallel on the input side at 240V and in series on the DC side.
Your question caused me greater reflection and I would guess it was the DC isolation that was important if I was putting them in series. Is this a teachable moment?
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