Mgbv8

Finally finished the Eiger, rides great , solid assist and throttle. [ATTACH type=full" alt="48483]48483[/ATTACH]

Finally finished the Eiger, rides great , solid assist and throttle.

Great suggestion [mention=19370]peter.c[/mention] was able to find a good deal on a new one on eBay for under £20 and it fits perfectly

It was the BMS, both input and output, , fully charged to 42.4v , I now know the BMS was stopping me taking charge off of the battery, I e using the motor. The thumb control works as expected and I get movement woop, time for a test ride tomorrow hopefully

Good news, fitted a new Daly BMS and it's charging past its original 41.1 and the BMS no longer restricting the thru put , both +/- of battery and +BMS to - read the same value . Cells up to 4.16 and still charging

Cool, this is exactly what I was after, thanks

The charger is a modiary one from the old battery for this bike, I believe it puts out 42.1v supposedly at 2amps , which I've tested before. I've kept the battery charged up near to 100% , it was on 39.6v for a while , i.e a month while I was fitting the drive, but it showed that on the HUD when it worked. And since charged to the point at which the green light stays on the charger, I even left it on the green light for a further 6 hours to see if it altered the max charge but it didn't. The test I just did makes me think the BMS is bypassing the charger current when the BMS thinks the battery is full . Reason for this, is that with the charger plugged in, the battery pack +/- reads 41.1 but after the BMS it reads 42.1 , if that makes sense. My voltmeter is a mastech 8268 I've had for years, it's always been pretty accurate I think, but I will check with a second volt meter just to be sure. I appreciate all your suggestions, thanks for the continued help

I'm using a single rear cog onto a nuvinci 360 - so my chain is single cog to single cog, I've shortened the chain as much as I can, but it still has a bit of play So need some sort of chain guide / tensioner , and need some recommendations. Thanks

So I took the battery apart just now, all cell groups between 4.10 and 4.12 and a total + to - on the cells of 41.1 , there is a definite 0.5 to 0.7 loss coming through the BMS negative cable, I also wonder if the BMS is cutting out too soon given 4.1 seems low across each cell group £14 for a replacement BMS seems like a worthwhile test to see if they'll charge to 4.20 across each bank

It's my own fault, the mid motor and accessories is all brand new, the battery I bought as a factory second unit because it was scratched but supposedly brand new, and I've since discovered is a no return sold as seen, so maybe an expensive lesson in not going cheap when buying certain items

The weird thing is even at 40.6 it used to turn the display on at least and now it doesn't do that, like something else is faulty, even plugging in the charger whilst the battery is on the so there's 42.6, and the display doesnt work , I'll try and dig into the battery this week.

Yeah my next step is to open it up and take some cell by cell readings and see if it's an easyish fix, I've got a bench power supply, so I can try to bypass the BMS and charge an individual cell if it's down on charge and see if it recovers as a whole , or maybe I can swap out some 18650 cells if it's not beyond my expertise.

Ah right good to know thx for the quick reply , I'll stick it back on the charger, but sounds like that might be the culprit, might need to get a replacement or see if I can get it fixed

Hey, I've been rebuilding an old Kudos Eiger with a new bafang mid drive. Id put it all together and when I eased on the throttle the screen went off like it reset, so I tried again and as soon as I put load on the motor the screen died. And now the screen is dead, no response, I checked all the connections , my 36v battery at full charge seems to be 40.6v - I do have the diagnostic cable so was going to see if the motor is still alive. I'm guessing it's either the control board, the display computer or the battery , all of which is brand new. I've had the screen on for a while testing settings and spinning the motor with the throttle and no chain ie load But I feel like I've now killed something or the battery is a lemon. Thoughts appreciated

I'm guessing the bafang is still preferred quality over the tongsheng tsdz2? There's only about £60 price difference £265 Vs £330, I'm guessing forum members use both with equal satisfaction?