How to make a lightweight battery

[Deleted member 4366]

Take one Aldi aluminium water bottle and cut the bottom off with a Dremmel:



10 cells will fit in with the BMS alongside, or you can get 12 cells with the BMS on top. The BMS I used is just too big to fit clat, but I think it might fit if you rounded off the corners.



It needs a charge socket.


The socket was epoxied in, then I had to cut down the top a bit:

before


after

 

[Deleted member 4366]

cell pack welded and ready to wire up:


Cell-pack wired and wrapped:



Finished 36v 6Ah battery with LG HG2 cells - a smidgeon over 1 kg. Cost about £100 in total. It's the first totally waterproof battery I've ever had:



How it looks on the bike:

 

[anotherkiwi]

You have a typo d8veh, 36 V 6 Ah.

Show us a photo of the bottom please. I guess that is where the wire comes out. Two of those in parallel is still only 2.17 kg ! Would work great with a BBS01 or GSM with internal controller!

 

[tommie]

Great to throw in the saddle bag as a reserve?

 

[Deleted member 4366]

You have a typo d8veh, 36 V 6 Ah.

Show us a photo of the bottom please. I guess that is where the wire comes out. Two of those in parallel is still only 2.17 kg ! Would work great with a BBS01 or GSM with internal controller!

The bottom is just a round piece of 5mm plywood with a hole for the wires to come out at the moment. This is what will be printed off out of plastic in the next couple of days:

 

[asc99c]

Great battery, you make it look easy to build this stuff!

Can I ask about the choice of cells? You've gone with high drain IMRs, but I wouldn't think you need high drain, presumably 35w or so per cell which you could get from higher capacity (3500mAh MJ1) cells also.

Sent from my ONEPLUS A3003 using Tapatalk

 

[Deleted member 4366]

Only 2 cells in parallel means that I need a battery capable of 10 real amps from each one. The Xiongda controller is only 11 amps, but I'll probably increase it to 15 or 16A later, just to see how the motor performs. I also want to try 12S and 15 amps, but I'll have to make another battery for that.

 

[KirstinS]

Great work ! When I convert my Ti roadie one day.....this is the battery to go with it

 

[STEVEMANFA]

Nice work and it looks fab on the bike

 

[Deleted member 4366]

The new base is coming shortly;

 

[drummerian]

Love the battery build.

Are you sourcing your cells and BMS in the UK, if so would you particularly recommend any supplier? I have just repaired my Sunkko 788 welder so keen to put together a similar pack to this one, though perhaps 10s3p.

 

[Deleted member 4366]

I got my last cells from here:

http://www.ebay.co.uk/itm/4x-LG-Genuine-Lion-Batteries-HG2-18650-3000MAh-20-30A-IMR-Rechargeable-Batteries/201805669216?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

 

[Woosh]

they charge £3.95 for p&p.

did they send them by post? if they did, naughty, naughty...

 

[Deleted member 4366]

they charge £3.95 for p&p.

It's the total cost that counts. 20 cells for £86.75. can you find them cheaper?

 

[anotherkiwi]

4.78 € from nkon compared to your 4.83 € so 0.05 E cheaper shipping included of course. I am interested in your battery performance report next! Come on get out there and use the damned thing, the weather is great!

 

[Woosh]

It's the total cost that counts. 20 cells for £86.75. can you find them cheaper?

no, but I already have Samsung cells in the workshop. I was looking for ways to make a kit for the Brompton but not interested enough to start anything.
I am only beginning to get really interested since reading your thread on the YTW06 motor.
I

 

[KirstinS]

I got my last cells from here:

http://www.ebay.co.uk/itm/4x-LG-Genuine-Lion-Batteries-HG2-18650-3000MAh-20-30A-IMR-Rechargeable-Batteries/201805669216?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

Hi d8veh

My lipo packs are dying and 18650 have moved on so much I won't be replaceing them

Instead id like to make two of the bottle batteries. Use one for commutes and use two for longer trips. I still have a huge and heavy 16ah dolphin pack from Jimmy which shows no sign of degradation after 18 months hard use

I'd probably go for 3400mah cells which I can get ffrom nkon.nl

But would you be able to recommend me a BMS (and where to buy?)

Many thanks

 

[Deleted member 4366]

This is the BMS I used, which fits in the Aldi bottle next to the cells:
https://www.aliexpress.com/item/10S-36V-Li-ion-Lithium-Cell-40A-18650-Battery-Protection-BMS-PCB-Board-Balance/32697273276.html?spm=2114.search0104.3.58.DLQ3gY&ws_ab_test=searchweb0_0,searchweb201602_4_10152_10065_10151_10130_10068_10209_10192_10190_5430020_5410020_10307_10301_10137_10303_10060_10155_10154_5370011_10056_10055_10054_10059_100031_10099_5400020_10103_10102_10052_10053_10107_10050_10142_10051_5380020_10084_10083_10080_10082_10081_10110_10111_5420020_10112_5390011_10113_10114_10179_10312_10313_10314_10184_10315_10078_10079_10210_10073,searchweb201603_2,ppcSwitch_4&btsid=bb543e8c-2aed-42d3-8251-2920ddf33101&algo_expid=df1593c6-cae5-4035-8815-274c94e5401b-7&algo_pvid=df1593c6-cae5-4035-8815-274c94e5401b&transAbTest=ae803_3

The Aldi bottle is 80mm O/D. I have since bought some similar bottles from Ebay, but it turns out that they're only 73mm O/D, which means that there's no room for that BMS, though you can still easily get 10 cells in. I found this BMS, which might just fit, so i will order a couple to see. They're only 16 amps, so only good for up to 15A controllers:
https://www.aliexpress.com/item/New-10S-36V-37V-16A-Li-ion-Lithium-Battery-BMS-PCB-PCM-Suitable-For-Ebike-Electric/32823734788.html?spm=2114.search0104.3.95.DLQ3gY&ws_ab_test=searchweb0_0,searchweb201602_4_10152_10065_10151_10130_10068_10209_10192_10190_5430020_5410020_10307_10301_10137_10303_10060_10155_10154_5370011_10056_10055_10054_10059_100031_10099_5400020_10103_10102_10052_10053_10107_10050_10142_10051_5380020_10084_10083_10080_10082_10081_10110_10111_5420020_10112_5390011_10113_10114_10179_10312_10313_10314_10184_10315_10078_10079_10210_10073,searchweb201603_2,ppcSwitch_4&btsid=bb543e8c-2aed-42d3-8251-2920ddf33101&algo_expid=df1593c6-cae5-4035-8815-274c94e5401b-

Here you can see the problem:

 

[KirstinS]

This is the BMS I used, which fits in the Aldi bottle next to the cells:
https://www.aliexpress.com/item/10S-36V-Li-ion-Lithium-Cell-40A-18650-Battery-Protection-BMS-PCB-Board-Balance/32697273276.html?spm=2114.search0104.3.58.DLQ3gY&ws_ab_test=searchweb0_0,searchweb201602_4_10152_10065_10151_10130_10068_10209_10192_10190_5430020_5410020_10307_10301_10137_10303_10060_10155_10154_5370011_10056_10055_10054_10059_100031_10099_5400020_10103_10102_10052_10053_10107_10050_10142_10051_5380020_10084_10083_10080_10082_10081_10110_10111_5420020_10112_5390011_10113_10114_10179_10312_10313_10314_10184_10315_10078_10079_10210_10073,searchweb201603_2,ppcSwitch_4&btsid=bb543e8c-2aed-42d3-8251-2920ddf33101&algo_expid=df1593c6-cae5-4035-8815-274c94e5401b-7&algo_pvid=df1593c6-cae5-4035-8815-274c94e5401b&transAbTest=ae803_3

The Aldi bottle is 80mm O/D. I have since bought some similar bottles from Ebay, but it turns out that they're only 73mm O/D, which means that there's no room for that BMS, though you can still easily get 10 cells in. I found this BMS, which might just fit, so i will order a couple to see. They're only 16 amps, so only good for up to 15A controllers:
https://www.aliexpress.com/item/New-10S-36V-37V-16A-Li-ion-Lithium-Battery-BMS-PCB-PCM-Suitable-For-Ebike-Electric/32823734788.html?spm=2114.search0104.3.95.DLQ3gY&ws_ab_test=searchweb0_0,searchweb201602_4_10152_10065_10151_10130_10068_10209_10192_10190_5430020_5410020_10307_10301_10137_10303_10060_10155_10154_5370011_10056_10055_10054_10059_100031_10099_5400020_10103_10102_10052_10053_10107_10050_10142_10051_5380020_10084_10083_10080_10082_10081_10110_10111_5420020_10112_5390011_10113_10114_10179_10312_10313_10314_10184_10315_10078_10079_10210_10073,searchweb201603_2,ppcSwitch_4&btsid=bb543e8c-2aed-42d3-8251-2920ddf33101&algo_expid=df1593c6-cae5-4035-8815-274c94e5401b-

Here you can see the problem:

View attachment 20728

View attachment 20729

Thank you , really useful stuff. And that bms is also on eBay. Had you said you just had in stock it's the one I would order. Your better fitting 16a doesn't work for me sadly. My GSM pulls more and I'm after interchangeable packs across my bikes (like lipo but without the hassle and risk)

10s2p of cells works for me but I'll be sure to measure the donor bottles very carefully first

 

[Charliefox]

cell pack welded and ready to wire up:
View attachment 20273

Cell-pack wired and wrapped:

View attachment 20274

Finished 36v 6Ah battery with LG HG2 cells - a smidgeon over 1 kg. Cost about £100 in total. It's the first totally waterproof battery I've ever had:

View attachment 20275

How it looks on the bike:

View attachment 20276

Is that your soup in the other bottle or the controller? So 2 for not much more than 2 kilo and my 10amp battery weighs 4.6kg! I wonder why commercial batteries are so much heavier? Better start looking if Aldi still have any bottles left!