Diy solderless 18650 battery kit.

Nealh

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Plenty of BMS's on aliexpress all with differing amp ratings for £15- 25 or the more expensive smart bms from online China vendors.
The sense wires need to be connected in the correct order/sequence other wise you will smoke the bms, the bms is expecting to see a certain voltage reading from each cell string /group.
 

anotherkiwi

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I have finally made up my mind...

I really want to have the battery and the controller all neat and tidy in the triangle. I often do about 30 km there and back rides and mucking around in town. I HATE sag... So I am going for a 3P10S 9.4ish Ah battery which should cover the distance. And the sag with 3S you may ask? Well I'm going to break the piggy bank and go for the 30 Amp Sony Konion which is on offer at 5€ a pop. Current Samsung's sag badly but are 4 X 5.2 Amp = in theory 20.8 Amps. I figure even if the Sony are capable of half the advertised Amps (30) I will still have 45 Amps under the pedal so the sag issue will be toast.

When I need to go far I will parallel in 10 or 20 Ah of LiPo.

Comments on my logic are welcome.
 

Nealh

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Eglwyseg

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If you want to practice, I have a load of cells you can have. they're from faulty e-bike batteries, but most of the cells are OK.
Wow, sounds an offer I shouldn't refuse.

Assuming 'most' of the cells are OK, then there is the possibility of a working battery at the end of the project?

When I took my old battery apart and pulled out 40 cells, 3 were completely duff while about a dozen showed a slightly lower voltage while the rest were up to power.

What did take me though, there wasn't a single indication, whose batteries they were though I was lead to believe from the original vendor, the battery cells were Panasonic.

The big stumbler though, being OEM I assume, no signage of what capacity they are. It would be lovely to have a bucketful of used cells and grab some, all reading the same full voltage but without knowing their capacity it would be dangerous I would have thought to try make a working battery? Have you some way of knowing their capacity.

If to indulge and make a battery I would like to try make one similar in capacity to the one I bought to replace the old one as already I have discovered, due to the terrain in these parts, the extra capacity is really a must or I will make the mistake again, of draining the battery on a run which you all say, is a no,no, if we want to make our batteries last longer. Ideally I would be looking at say, a 10s 5p project with 3000ma cells, looking at a 36V 15 AH rig at the end of the job. 50 cells.

Joseph
 
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What I have is a whole load of the same type of faulty batteries with 10S7P configuration. They're mainly faulty because of leaking cells, so you can disassemble them to harvest the mostly non-leaking ones. I tnink they're 14Ah, so 2Ah per cell.

You have to collect from Telford, but that's not far from you.
 

anotherkiwi

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Eglwyseg

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What I have is a whole load of the same type of faulty batteries with 10S7P configuration. They're mainly faulty because of leaking cells, so you can disassemble them to harvest the mostly non-leaking ones. I tnink they're 14Ah, so 2Ah per cell.

You have to collect from Telford, but that's not far from you.

Yes, we live fairly closely, just checked on AA Autoroute, about 37 miles away but under an hour on the road. It would be a pleasant drive out.

May I leave this offer on hold for a few days and then I can see clear to get down.

Being newish to the site, is there some way I can PM you?

Thanks,

Joseph
 

anotherkiwi

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Top right corner ->
 

soundwave

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you cant use this lego system if using 30a cells as getting to 150f skip to the end of the vid.
 

anotherkiwi

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I would agree with you but:

- I am not drawing more than 6 Amps per cell, they only get to about 50° C at 15 Amps per cell
- I am going to use nickel strips not the stainless provided so much less resistance in my interconnects

Why use 30 Amp and not 15 then? Because I hate sag! And they are on sale. Kind of you thinking about my safety though :)
 

craiggor

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Jan 9, 2015
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New V2 kit on kickstarter $28 for 60 caps enough for 30 cells. Nickel coated copper and copper alloy contacts,nuts and bus bars. 20amp continuous per cell. New polymer fits together easier and longer terminal posts to allow for more bus bars.

Sent from my T1005 using Tapatalk
 
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