tomtag

I just thought it was quicker & easier to change the front. Also cheaper. I liked the idea of going to single speed at the front, as once I had the motor, I was always in top chainring. It let me get rid of front mech + shifter, giving a better space for display on handlebars as well. (& I think my front mech was bent so could never get it adjusted right.)

I have a 9 speed cassette at back and yes still using those gears, rear mech is a bit stretched forward on largest gear at back due to chain length, but doesn't seem to cause any issue and I don't really use it much in that gear. Bike has a 2009 SLX chainset & SRAM cassette & chain I think (not with me today) - Trek 6700 2009 I think it was one of these I bought. VXM Bicycle 104BCD Crank Oval Round 30T 32T 34T 36T 38T 40T 42T 44T 46T 48T 50T 52T XT Chainwheel Narrow Wide MTB Bike Chainring|Bicycle Crank & Chainwheel| - AliExpress

I converted an MTB with a 250w rear hub kit. I found the same & took all the original chainrings off, also the front mech, then added a 48t narrow/wide chainring off aliexpress with no guide or mech, and over last 600 miles or so has been ideal. Mostly flattish commute, but also rides round the peaks are still good, would maybe be a challenge up a big hill if the battery was completely flat, but hasn't caught me out yet. Also didn't have to change length of chain.

I had a similar one from Yosepower that was 11.6Ah. It failed after one year after wear between the case & the cell wrapping (which really shouldn't have been able to contact each other). I think it was due to a combination of cramming in too many cells and an imperfect design.

Many thanks for the response. I think I will get this one ordered before stock disappears again.

Hi All, I am looking for a new battery after my previous one failed and wanted to ask for a little advice before I order. I have a MXUS XF08C rear wheel motor & am considering a 36V 15Ah battery with Samsung INR21700-50E cells in 3P10S arrangement. The advert suggests a continuous discharge of 25A with max of 50A. The controller is KT 36V 250W 6Mosfets 15A Brushless DC Sine Wave Controller, from the little I know it seems a suitable choice, but wondered if anyone could either help me confirm that, or advise otherwise? I have been trying to find a suitable battery, that will fit within the frame & has branded cells, this seems the best option so far. Thanks.

I didn't end up getting anywhere with Yosepower, after offering a discount they ended up deciding to ignore me & have not advised whether the same design problem has been resolved in their newer batteries, so will not purchase from them. I am now wondering if I could get a replacement on a cycle to work scheme. I have just asked Whoosh & eBike Batteries if they can do it so will see what they say, but wondered if anybody here knew of any seller that sells replacement batteries only on a cycle to work scheme? Thanks.

Well it looks like Yosepower have changed their mind and will not offer any discount, I have asked again, but doesn't look promising. Does anyone have any reccomendations on where is a good battery supplier for a replacement? I bought the kit from PSW power so could try there, but not sure where else to look.

But then I think I would break the warranty sticker and lose any warranty on day 1. Even if I just opened to check the design was improved. Not sure which would be the best way to go. Blind faith and a warranty, or reassurance with no warranty? Opinions welcomed.

If I understand the question correctly, the answer is no. All of the thick wires from the BMS run down a different side of the battery where there is no damage to cells. This side has a fully enclosed 'groove' so no chance of the case grounding onto the cell surface. The other side had an open section in the groove that allowed the contact. Is this an answer that makes sense?

Hi WheeliePete, thanks for the feedback on battery choices above, very useful. I may well have to stay with the bottle version due to space, but will spend a bit of time measuring up to confirm. Yes I have sent photos & an explanation. TBH they didn't seem overly interested, just said cannot replace for free but may offer discount. I have asked if the design has now changed if I do look at going for the same again. I think they have now closed down for Chinese New Year, possibly until Feb 7th, so I may be waiting for a little while for the next response.

So I have had a response and they won't replace, as out of the 18month warranty, but have suggested a discount on a new one. Not sure how much yet, I need to choose one & I think they will let me know. So I have looked at the website, my current battery is 36v 11.6Ah. The one I had was already a tight fit, so I was considering the same size again to be sure it fits. But, would anyone be able to offer any advice on what is best to get? This would I think be a direct swap: 36V 10.4Ah Bottle Battery E-Bike Li-ion Accu (yosepower.com) Or would I be better with this: 36V 13Ah Hailong Li-ion Battery E-Bike with 5 Gold-plated Round Plug (yosepower.com) They both say 10A/20A. I guess without actual cell details it is hard to say what is best? It is a MXUS XF08C 250w motor I have. Also, is this a good opportunity to move to 48V, would there be any benefit in that?

Just less than 2 years, but only had an 18 month warranty. I will contact Yosepower & see if there is anything can be done, but not sure if I will get anywhere.

Thanks for the input. So is the general opinion that this beyond help, and not even worth replacing the cells. So it's a new battery? If so would anybody be able to recommend where to get a new one? This was £170 at yosepower.

It is where the slots run inside the case and stop the internals rotating.

I guess it is the source of the spark when I opened it. But looking inside the case, there are corresponding scorch marks which suggest it has happened when it was in place, not when I took apart. I can't see how this has happened, unless it is from vibration over time or impact. I am now going to try and check if these cells are in the groups that are showing low voltage, but then not sure if it really matters, I guess it is no good without replacing these cells? Even then I would have to work out what happened and resolve it when rebuilt.

I was trying to track the balance wires back to the cells and saw this......

Can you see the photo ok?

So I tested each group against black, but was seeing the cumulative voltage of the group's I think. Results as per the photo. Does it show 2 group's with issues?

You were right, that connector was a struggle, but it is out. 10 white and 1 black in it

I have now got hold of a meter & taken the battery internals out of the case. I initially took the top off the battery & there was a crack/spark after I had removed the lid. I do not think I had disturbed anything at this point, so maybe indicative of a damaged/poor/dislodged connection? I would think it should be quite difficult to have this happen with a battery in good condition? I was hoping for a bit of help now on the best method to test. I assume I need to test the voltage of all 10 sets of 4 cells? I have identified the 11 wires to test, but what I am not sure of is best setting for meter (Direct Current, at suitable voltage setting?) Nor how best to get onto those connections, or if I need to disconnect anything first?

Hi Bikes4Two, thanks for this. I will also look at the condition of the joints when I take the battery apart. I hope you did find the problem and you continue with no issues

This info is great, thanks very much. I am well up for trying to find out more about what has happened. It will take me a couple of days to get hold of a meter and find a bit of time but would really appreciate the support.

Should I leave it on longer?