Replacement battery

Clive Belfield

Pedelecer
Oct 9, 2019
28
0
Hi folks
I am looking to replace the battery on my ebike conversion kit. It is a 36volt , 250 watt front wheel system with a bottle mount battery. I have read a lot about good cells and bad cells and and am confused.
Can I seek recommendations as to which "good" one to buy
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,950
Basildon
Is the controller integrated or separate? Which type of bottle battery is it? How much space do you have? A photo of your bike might help.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,950
Basildon
You can use any frame-mounted battery you want. Generally, if you buy from a proper retailer, like Eclipse Bikes, you get decent quality and support. I always buy from China (EBay, Aliexpress, BMSBattery, PSWPower, Topbike kit, Elifebike, etc) and I've never been disappointed. Make sure it has branded cells in it, like Samsung, Panasonic, LG. Buying from China is cheaper, but you generally don't get any support.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
16,586
6,463
58
West Sx RH
You could use any battery type and mount it in the triangle, what you need to let us know is the controller current. If it is 15a max then the Sam 29E celled ones are very good and have good cycle life, I have in the past berated the 29E a little but then again I abused the battery by derestricting and applying to many amps. Although abused a little my batteries are now over 5 years old and still return me 30+ miles from a charge albeit I have to only use PAS 2 max for the mileage which is ok for my commuting /errand usage with or without a trailer.
LG MH1 is another good cell which is being used a bit more now and also the Panasonic BD cell (both 3200mah cells), other wise link any you find and we can have a look at the specs. Ideally you are looking for a battery with 5 cells in parallel so a 14.5ah or 16ah battery and ones that actually state which type of battery cell is used in side.
Stay clear of any with LG MG1 cells as they did not perform to well.
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
16,586
6,463
58
West Sx RH
The battery with carrier is quite long approx. 430mm needed to fit it, the rail fitting is all aluminium except the bottom end part which is a plastic cover. For down tube fixing it sits very nicely as it is narrow and plenty options to position for rivnuts fixing or adding extra rivnuts.
 

jarob10

Esteemed Pedelecer
Jan 22, 2017
265
78
49
Uk
The battery with carrier is quite long approx. 430mm needed to fit it, the rail fitting is all aluminium except the bottom end part which is a plastic cover. For down tube fixing it sits very nicely as it is narrow and plenty options to position for rivnuts fixing or adding extra rivnuts.
Any reason why
You could use any battery type and mount it in the triangle, what you need to let us know is the controller current. If it is 15a max then the Sam 29E celled ones are very good and have good cycle life, I have in the past berated the 29E a little but then again I abused the battery by derestricting and applying to many amps. Although abused a little my batteries are now over 5 years old and still return me 30+ miles from a charge albeit I have to only use PAS 2 max for the mileage which is ok for my commuting /errand usage with or without a trailer.
LG MH1 is another good cell which is being used a bit more now and also the Panasonic BD cell (both 3200mah cells), other wise link any you find and we can have a look at the specs. Ideally you are looking for a battery with 5 cells in parallel so a 14.5ah or 16ah battery and ones that actually state which type of battery cell is used in side.
Stay clear of any with LG MG1 cells as they did not perform to well.
Any reason why the Samsung 35e isn’t on that list? My replacement 35e celled battery beats its 29e version in current delivery & range
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
16,586
6,463
58
West Sx RH
It's documented on ES that long term cycle testing at 1c by the forum testers shows that 3500mah cells perform worse then then lower mah cells in the long term. Another factor they use is is price per mah and consistently 29E and LG M29 are one of the best cells.
It all boils down to current required and range but cells can't deliver both you have to compromise.
 

jarob10

Esteemed Pedelecer
Jan 22, 2017
265
78
49
Uk
Thanks jarob10, where did you get your battery pack from?
It was hard to find - I ended up going with bmsbattery. 36v 21Ah hailong battery, along with a q128c motor was £400 inc uk delivery. No duty to pay.

I wasn’t aware of the inferior long life cycle issues though. Time will tell, but right now the 35e trounces it’s 29e equivalent for me. I’m getting at least 25% more range with a lot less voltage sag.