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Ok a quick update on my battery purchase... I received the Lithium-Ion battery pack from BMS Battery in China this morning, it arrived nice and early by FedEx in super quick time (less than 4 days). The battery is 36V 10Ah, measuring 7.5cm X 14cm X 16cm and weighing in at 2.5kg. It's supposed...

Hi Scotty, Thanks for reply, maybe the 6-7 months I got then was not unreasonable given the small size of the battery pack and the daily load put on it. These were LiFePo4 cells (the packet-shaped type)..I used the BMS which came with the battery pack. What you're suggesting sounds like...

Following up this thread for those with an interest in my eBay LiFePo4 battery failure... I did manage to the contact the seller and after requesting photos of the battery he told me that he can no longer supply suitable individual replacement cells as he's changed supply. So it looks like I...

Thanks for the info and advice guys! I hadn't given any thought to a bottle battery but maybe I should. I'm experimenting with the heavier weight on front of bike today to see how much difference it makes to handling, my existing 1.89kg bat doesn't much a lot of difference. Scottyf I'm envious...

Hi all, As I'm running off one 5Ah battery now which I've had for a while, I'm a bit worried about it dying and so have decided to order a new battery this week. I have a couple of questions I'm hoping some of you self-builders can help me with.. I'm just about to place an order with BMS...

I use my bike on the roads, but only on quiet roads like bus route lanes and small roads mainly. I don't feel too confident on roundabouts, dual carriage ways and motorways because at the end of the day it's a bicycle I'm riding amongst fast moving traffic and I have no indicators etc. I see...

Thanks for the info flecc and for all the help guys, feel much placed to make a decision now and I need to make one soon! I'm a bit nervous running only with my old battery which could give out at any time...can't imagine a single day without my bike ;-)

Interesting, that size might be ideal replacement then for my LiFePo4.. I'm not familiar with that type of battery, does it have any benefits or draw backs over LiFePo4?

Thanks Frank, might give them ago I think and go for 10Ah this time. Is that size for the 10Ah battery right?? 75mm X 140mm X 160mm seems rather small.

This bike just caught my interest as I'm considering lighter alternatives to my 23kg folder. Spotted them selling on eBay from Germany on auction. The motor is only 120W and the battery is only 15v so I'm guessing it's not got much umpf behind it. 9KG for the entire bike has to be a world record...

Flecc do you think I've just been unlucky with one of the cells going, or do you think 6-7 months life-span on a small 5Ah battery is about what you would expect under daily usage? I must admit i have been fairly punishing with it, riding on full power all the time and over the last few months...

I have just stripped the battery down and can see the 12 individual cells and how to separate them. It certainly looks feasible to isolate and replace the bad cell. Won't know if it's worthwhile though proceeding with the next stage until I hear back from the vendor. I've just e-mailed...

Thanks flecc that's a useful starting point. As this battery is destined for scrap there's nothing to lose by testing each cell under load until I can isolate it, depending on whether the vendor can supply a replacement cell. Glad I didn't snip out the BMS now! Always best to check on the forum...

It's giving 39.5v off the good battery. I wonder should I try and isolate the bad cell and replace it, or just replace the entire battery. I'm not even sure the supplier would supply individual cells but no harm in asking.

I forgot to mention.. I took a battery voltage reading with a meter yesterday immediately after charging and testing the battery on the bike..it was reading 38.4v. Today I took a second reading, it's now 37.7v.

I ride my bike effectively with a single gear all the time! I leave it in the highest (7th) gear with the chain on the lowest rear sprocket and largest crank sprocket for maximum torque. I find this setup is the only way that I'm able to keep up with the motor using the highest assist power...

One of my little 5Ah LiFePo4 batteries has failed after 7 months of usage and I'm carrying out some diagnostics on it to see whether the problem is the battery cells or the BMS and have a question I'm hoping someone might be able to help with.. First I'll describe the status and behaviour of...

Hi Alan, Hope you're keeping well and busy? I tried to do your spreadsheet online a while back but didn't have any luck as it wouldn't let me edit it. So I've put the info you wanted below.. Sorry about the delay replying. I'm so busy these days with work and other stuff...started doing forex...

It seems I was a bit premature in my post, as luck would have it I suffered two break downs not long after the post just a week apart. Sods Law! The first one happened last week and luckily turned out to be nothing serious. I was riding along on my daily commute to the sorting office and the...