Greeting! I am new here

sjpt

Esteemed Pedelecer
Jun 8, 2018
3,832
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Winchester
If you search around the forum you'll find lots of posts about battery building. Unless you are very sure of what you are doing, and have all the right equipment the summary is don't.

Battery fires are very dangerous, and the two commonest reasons behind them seem to be badly built batteries and the use of the wrong charger (or wrong use of the right charger).

If you do go ahead wait until you have had lots of advice/feedback from the experts here so you do become really sure first. Not an area where trail and error is a good way to learn. Good description of the process at https://www.instructables.com/How-to-Make-a-Lithium-Battery-for-an-Electric-Bicy/ but I can't vouch for any issues with it.
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
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Why ?
Unless you have a special need to use certain cell types/brand or need a batteyr to for design reasons then it is far cheaper to buy a battery.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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Your battery cost will likely be no cheaper then buying , one will need a good mini spot welder to carry out the welding of interconnectors . A good spot welder and powerful batteyr source to provide the high amps for the process will cost approx. £200 +, one can buy very cheap all in one spot welders but these are for occassional spots and repairs so I wouldn't recommend that option.

There are some battery threads on the forum with pics and also look at Endless Sphere forum before attemtping batteyr builds.
Safety is of importance so one must also use the various insulation materials also needed.
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,814
3,152
Telford
I like to bulid battery pack for ebike myself.I am glad to sharebetween each other
It's very important to use the ring insulators on the positive ends of the cells unless you have a suitable alternative arrangement. That's the biggest mistake I see on amateur and YouTube builds. The other main issue is the routing of any conductors. You must separate them by sufficient insulation if they cross any cells or conductors that are at a different voltage. Sufficient insulation is not the actual conductor's PVC/PTFae insulation, nor the heatshrink covering the cells, which can soon get rubbed through.

After that, it's just a case of making sure that nothing can move.

One other thing, it's surprisingly easy to drop a nickel strip in the wrong place when you're welding the pack. You'll get big sparks and/or it'll start glowing bright red, while your pack starts to go into thermal runaway, so make sure you're ready to deal with that in case it happens.

Making batteries yourself doesn't really make sense these days unless you have a special reason.
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
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I cover the the battery cells I'm not working on with thick card and old cereal packet is idela for cutting up to use for temporary insulation cover for the exposed areas. The power feed off takes need consideration and thinking about for best equal power flow, don't take it for granted to just take all the power from the very last cell as most batteries do.
Do your research first .
 

Harriton

Just Joined
Jun 13, 2024
3
0
It's very important to use the ring insulators on the positive ends of the cells unless you have a suitable alternative arrangement. That's the biggest mistake I see on amateur and YouTube builds. The other main issue is the routing of any conductors. You must separate them by sufficient insulation if they cross any cells or conductors that are at a different voltage. Sufficient insulation is not the actual conductor's PVC/PTFae insulation, nor the heatshrink covering the cells, which can soon get rubbed through.

After that, it's just a case of making sure that nothing can move.

One other thing, it's surprisingly easy to drop a nickel strip in the wrong place when you're welding the pack. You'll get big sparks and/or it'll start glowing bright red, while your pack starts to go into thermal runaway, so make sure you're ready to deal with that in case it happens.

Making batteries yourself doesn't really make sense these days unless you have a special reason.
Yes! I agree it. Lithium battery is pretty dangerous.I will take care
 

thelarkbox

Esteemed Pedelecer
Aug 23, 2023
1,209
371
oxon
Why build the battery yourself? is your bike/ev config special ?
Do you have a particular range or weight target to hit?
Or is it simply an area of personal interest and opportunity to learn and expand skills?

We like project details in here ;)
 

Harriton

Just Joined
Jun 13, 2024
3
0
Why build the battery yourself? is your bike/ev config special ?
Do you have a particular range or weight target to hit?
Or is it simply an area of personal interest and opportunity to learn and expand skills?

We like project details in here ;)
Just personal interest. Maybe I post in one day.