Nisse977

I can not be really sure without taking the battery apart and measure the balance-leads. When I build a new battery I plan to install a small smart BMS in parallell with the stock BMS so I can check balance status now and then. I really like riding this old Gotway Tesla. Unfortunately I got my first punkture a few days ago, so Im now waiting for a ned tire and hose to arrive. My old tire is pretty worn down anyway. If I would buy a newer same type of wheel, I think I would go for the Kingsong 16X or maybe InMotion V12 HS. We are four people in my familjy, and all of them like to ride EUC, even my wife, so I will probably buy more wheels in the future The damped wheels seems nice, but a bit big and heavy. My wheel size is so easy to carry up some stairs or walk into a store without anyone complaining. At the same time I would not want a slower wheel that does not ride at 30mph+ (48km/h) like my old Tesla does.

Yes I did not charge it to 100% at that particular ride. But still big fluctuations between 93% and 17% during the ride. I normaly don´t charge to 100% because I live on a hight, so almost everywhere I want to go, its starts with downhill. I charge to 90% most of the time. But I have tried 100% to

Yes it accually charges just fine to 84v so I do not believe I have unbalanced cells, but who knows.

With current battery that "works" I do not get very good range if I dont ride really slow. The voltage sag and spikes are big. Like yesterday I was out on a 17km ride and the battery fluctuated between 93% and 17% during that short ride. Look here: https://euc.world/tour/637491240964064 So with a new battery I hope to get less voltage fluctuations and better range

Ah thanks, really good tip there! I am 85kg and usually ride at 45km/h with my Tesla. The previus owner was a 100-110kg guy. I think he usually rode it at low speed, but he did ride it att 55km/h once. It was with fully charged battery so everything went good, no accidents. Then after that he read on forums that 55km/h is not a safe speed with the Tesla V1, so after that he kept it to max 45km/h.

No the Samsung 50S is not expensive for me as I listed in my last post. But I do not know if I rather want the Molicel P42a instead, or P45B. But there is no need to decide on that now, because I have a couple of batterybuilds to finish before taking on this one

Hi! No I am not planning to buy a newer wheel in the near future. But I might do that after a few years. I got my Tesla V1 for 400$, thats a ok price I think I guess Kingsong 16X would be a good similar wheel to buy. Do you have other tips or suggestions? Thanks for responding! That was accual battery amps (the 45A), the motoramps are up to about 90-100A. Yes the 18650GA was listed as 3,5mAh when they came out, and later on they where relisted as 3,35mAh. In the test from 2016 when the 18650GA where new, the tester got about 3200mAh out of the cells at low current (2-5A) and the nominal voltage was stated 3,6v in the test, as on most li-ion cells, so 3,6v x 3,2 x 80 = 921Wh. But if we go by the spec 3,5Ah, we get 1008Wh witch is closer to Gotways spec of 1020Wh I have tested some 18650GA cells myself, and at 1A load (that is really low) I got about 3200-3300mAh out of them. I have tested 36 of them, and that was the avarage capacity From my experience with diffrent cells, the 18650GA is not a good cell for this application, it sags to much for my taste during load in this 20S4P configuration. But you are right, they are not new, so new ones would probably be better. In another batterybuild I did, I used even worse cells, but I got the cells totally for free, and the battery is a 660cell 20S33P (yes 33P!) so it works nicely because of all cells in parallel. It´s a battery for a electric moped. Pulling only max about 1A per cell at full load I think about using Molicel P42A, P45B or Samsung 50S in this batterybuild for the Tesla V1. I prefer to get as low of a voltage-sag as possible in front of getting the maximum range. But the cell-price is of course a factor to think about. I do not want to pay double the price for a cell that is just a little better then another one like the P50B cells... The price I pay for 80-cells / The real total capacity and real total continuous ampdraw of 20S4P (Mooch test): 316€ Molicel P42a / 1152Wh, 120A 328€ Samsung 50S / 1440Wh, 80A 382€ Ampace JP40 / 1152Wh, 180A 428€ Molicel P45B / 1296Wh, 140A 1116€ Molicel P50B / 1440Wh, 140A (way to expensive cell for me) To get a 382€ 80-cell pack with Ampace JP40, I need to buy 130pc of them for about 620€.... Nice to hear about your wheels and that they still use the original battery, good stuff

Hi! I have bought a 2nd hand 6 year old Gotway Tesla V1. It still works fine, feels powerful enough for my riding (in town to work) But it needs a modern battery... I have made a few batteries for diffrent EVs like electric longboards, electric moped and some handicap vehicles. My first electric longboard had a battery that I made out of Panasonic 18650GA cells, the same model that Tesla V1 (1020Wh) use. In my longboard I made a 12S3P battery and I was pulling a maximum of 40A from the battery. Thats like 12-13A per cell. These 18650GA cells does not work great with that current level, they are pretty weak (but I did not know that when I built that battery) I could see the voltage drop badly during hard acceleration, and spiking during hard braking. Anyway.. This Tesla V1 are also using the 18650GA cells, but in a 20S4P configuration. When riding I can see in the EUC World App that I´m pulling around 40-45A from the battery at max. And this put a similar load on the cells like in my first longboard, witch results in bad voltage sag and spikes during accelerationg/braking. Spec says its a 84v wheel and 1020Wh, but its really a 72v battery (nominal voltage) with a 84v fully charged voltage. The specified capacity states 1020Wh, but is it really 1020Wh? From test back in 2016, the 18650GA cells put out about 3200mAh at low current test 2-5A. https://lygte-info.dk/review/batteries2012/Sanyo NCR18650GA 3500mAh (Red) UK.html This means that there is accually only about 921Wh in the pack, not 1020Wh. (3,2Ah x 4) x 72v = 921,6Wh. But the problem is that the capacity of these cells is not very useful in this application because of heavy voltage sag.. If I ride the wheel down to 50% SoC and hit a uphill road and continue to ride at normal speeds, the voltage will sag down to 15% and the wheel will start beeping and tiltback so I have to lower my speed, therefore I need to always keep the wheel at minimum 60% SoC, but not over 90% SoC, then I get problems with braking caused by voltage spiking over 4,2v per cell... This problem would not happen if the battery was made out of high current cells. Or if i ride really slow, but who does that? So now I am planning to building a new battery with modern high current cells. And from the looks of this thread, there is even a posibility to go for 21700 cells if I rearange some stuff inside the wheel, and cut away one side of the batterycompartments, like in the Mantraguy photos. I am then thinking about 21700 cells like, Molicel, P42a, or P45B or P50B (expensive) other options are the new Ampace JP40 (or EVE 40PL) but Samsung 50S is a cheaper cell to buy, but not as high current as the others I mentioned, but maybe that would be okey, I dont know. If I would go for 18650 cells, I guess Molicel P28B or P30B would be ok choices, but they are expensive. The least expensive cells that I can buy is P42a or 50S. Have you guys had any luck building better batteries for Tesla V1, or have just left that wheel and go on to newer models? /Nisse977