Can I get someone to do this? Suggestions?

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sangesf
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 Does anyone know anybody or place that will help me take 2 lifepo4 batteries with some dead cells and reconfigure them into one 36v for me?

I have one 21v one with a few bad cells (21v 20 ah) and a 24v 30ah one with a few bad cells and need them reconfigured into a 36v xxah and add a 36v BMS.

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Reid250
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Re: Can I get someone to do this? Suggestions?

An indication of which planet you live on may encourage someone nearby to help?

sangesf
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Re: Can I get someone to do this? Suggestions?

Don't know about you, but I live on planet earth. :)

I don't want a nearby "person" to do it, I'm curious if anyone knows of a "company" that does that...
I'll ship it anywhere I have to.

P.S. I've looked around the Internet, but all I've seen so far are places that will do Nicads and nimh and every other type except for lifepo4 which is what I have

reikiman
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Re: Can I get someone to do this? Suggestions?

One issue will be about the brand of cell in those packs and whether the various cells are the same capacity or in similar condition. For example if the two packs saw different amount of use one pack will have seen more use and those cells will be weaker than the other pack. It's typically not a good idea to mix cells of different characteristics. Also the kind of cell might make one shop more suitable than another or whether one shop or another carries the kind of BMS you're interested in having.

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sangesf
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Re: Can I get someone to do this? Suggestions?

sangesf wrote:

Don't know about you, but I live on planet earth. :)

I don't want a nearby "person" to do it, I'm curious if anyone knows of a "company" that does that...
I'll ship it anywhere I have to.

P.S. I've looked around the Internet, but all I've seen so far are places that will do Nicads and nimh and every other type except for lifepo4 which is what I have

They are the same cells.

They are both from the same company
I have pulled out the bad cells, and tested each one that was good after charging them and then putting a load on each one for 30 mins, and they ALL have the same voltage +/- .02 so they are all good, i just have no clue how to put them together, I'm not going to solder them, of course, because that would be bad.

Does anyone know how to connect these cells together without solder?

If i can do that, then I'll do it myself and then just buy a BMS and add it to the new pack.

Reid250
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Re: Can I get someone to do this? Suggestions?

Please describe how the current battery pack is assembled? Why do you say soldering them is bad? I only know of 3 ways to connect cells into a battery. Solder, bolt straps from cell to cell or use wires with bayonet connections. It should not matter what the cell is made of, any battery shop should be willing to build you a pack from your cells. Do you have a bike/scooter shop near by? Do you have an automotive electrical shop near by? Can you figure out which is positive and which is negative on each cell? Are you trying to build a simple series battery or a series parallel pack? What voltage do you need? What are you trying to power?

sangesf
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Re: Can I get someone to do this? Suggestions?

Reid250 wrote:

Please describe how the current battery pack is assembled? Why do you say soldering them is bad? I only know of 3 ways to connect cells into a battery. Solder, bolt straps from cell to cell or use wires with bayonet connections. It should not matter what the cell is made of, any battery shop should be willing to build you a pack from your cells. Do you have a bike/scooter shop near by? Do you have an automotive electrical shop near by? Can you figure out which is positive and which is negative on each cell? Are you trying to build a simple series battery or a series parallel pack? What voltage do you need? What are you trying to power?

They are lifepo4 cells. They are all 1.1 ah 3.2v cells Soldering onto any battery is bad because the heat needed to melt the solder would damage the cell.
I'm wanting to put them in a 12s19p configuration. Yes thas right 36v by ~21ah with the 238 cells. Think of the cells as double A batteries.. These are obviously the cylindrical cells. I took 125 from one pack and 213 from the other and they are all within .02 of each other after a 30min .5a draw. I'm wanting to change my series 24v 30ah lifepo4 and 12v sla into just a pure 36v lifepo4 and then add a small 12v sla 12ah battery just to run my accessories on my electrc bicyle.

Reid250
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Re: Can I get someone to do this? Suggestions?

AH, HA! Now we have enough info to help you. Now I understand your problem. There is of coarse a 4th way to connect cells and that is what you need. Spot welding tabs on which can then be soldered. I think you will need to build yourself a spot welder. You can Google for one or go to http://www.ledhacks.com/power/battery_tab_welder.htm I did some trouble shooting in a battery shop many years ago and found to get consistent tab welds we had to keep the power constant and the tips exactly the same sharpness. Each station began the shift with sharp tips and as the day went on, welds began to fail and the operators began twiddling the dials. We had to lock the controls and change the tips 4 times per shift for consistent results. I don't think you will find someone willing to take the risk of building you a pack from used cells? You will spend $100 on a spot welder, but learn a new skill. Just remember the tip sharpener is as important as the welder.
Consider a DC-DC converter in place of an additional battery.

Edit;
Here is another welder a supposed improvement on the first URL;

http://endless-sphere.com/forums/viewtopic.php?f=2&t=2633&hilit=welder

proton
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Re: Can I get someone to do this? Suggestions?

I guess you didn't look in the ' tab welding services ' offered section down below.
FalconEV can do this
contact me

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