From 36V 20Ah to bottle 36V 5Ah

[trietje]

Hello fellow cyclers,

I have a battery 36V 20Ah from China Ping batteries for about 3 years now.
Due to my shorter working distance now, the pack is too heavy to carry on a folding bicycle and I want to strip it down to a e.g. 36V 5Ah.
Build inside a bottle or whatever protection that is easy to mount and unmount on a folding biclyle.

How I start stripping this battery and strip it a less as necesairry to rebuild it?
The battery has one 'electronic controller plate' inside.
Do i need to buy a new controller plate (BMS)? Or can I do with out or use the old one e.g.?

Thanks,

trietje

 

[999zip999]

If you find a picture of a 36v 20ah Ping pouch batterry you can see that you wouldn't be able to do it. It's made 4p 12s and you want 1p 12s and the Ping cells can't support a 5ah battery for ebike use, maybe a 10ah but ALL would have to be cut it all apart and not be advised.

 

[wesnewell]

Not to mention a 20ah ping will handle 30A burst, while a 5ah made from the same cells would only be good for 5A and 7.5A burst. Buy a couple of 5ah 6s lipo acks and put in series for 5ah 44V good for 100A and about 3lbs.

 

[dogman dan]

Yeah, you'll need to make your new battery from some much more powerful cells than pings. If your motor is wimpy enough, you can get away with a 10 ah ping. Dissecting your current battery down to 10 ah is still a poor choice. First it will be difficult to cut it up into 10 ah sections. Second, the cells are now old, and won't support what a new 10 ah ping would. At 3 years, your ping may not last much more than another year. Maybe you can just suffer through the winter with it, and then get a new, smaller, but very powerful battery next summer?

 

[trietje]

Thank you al so much for the advice!
So I better use the last years of my Ping batteries. I have 2 of them: 36V 10Ah and 36V 15Ah (I thought it was 20Ah).

Now I commute with a folding bicycle at about 15 km a day. Before that was 30 km a day with the ping batteries and the 15Ah I used for long distance driving on my recumbent (+80 km).

Any idea where I buy my parts or a full bottle battery at best uality and price for the 15-20 km commute ride?

I can solder and have basic electrical skills.

My motor is a Bafang 36V 250W from China (folding bicycle). Another bicycle (mountainbike) has an Crystalite 36V

 

[dogman dan]

I see no reason not to just use the 10 ah pack on the folder. That setup is small enough for a pack that size. It's not bottle shaped, but at 10 pounds, it should be easy to find a small metal box to mount in on the folder. Or put it in a handlebar bag, with hard protection for it on the inside.

 

[999zip999]

There are some bottle batteries that will work and are made out of a LiMn cells. Meaning there are a lot of cheap bottle batteries that are just shit. The new NMC batteries are small and can be used with ebikes without going dead or burning down the house.

 

[dogman dan]

Yep, that would be a good choice for the next purchase, an 8-10 ah bottle battery, with a decent limn cell inside. Or a similar pack in another shape.

Your other bike, it still will need a larger battery, or one able to handle larger c rates.

 

[wesnewell]

I wouldn't trust a small NMC bottle battery. Here's what I'd use.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=37576
2 if one isn't enough range. Should get close to 15km per 4ah @ 25kph

 

[999zip999]

There is a learning curb with Lipo and must follow rules. Then you need a power supply and a balance charger a low voltage alarm. A safe place to charge and best to charge off the bike. Plus you must cycle the cells first to find duds. That just the start of the rules there's more. I havn't seen a NMC bottle battery yet. But havn't looked ? I was thinking you wanted a plug and play opion.