One of the cells in a string of nine had lost its ability to hold a charge and the two month sit had caused it to drag a whole string down to dead!
Dammit that is nine more 5S1P Cell packs that I am going to have to attempt to de-solder! Luckily I have just enough spare cells to swap them out.
Swapped out the nine dead cells and balance charged the whole pack, There may be signs of other cells in this box nearing failure but I want to get the pack back together and in the car so I can test a new rotory wafer switch I bought recently that should allow me to wire all 12 balance cables to the Hobbyking battery monitor widget in the car whilst driving and check the status of each bank whilst the car is under load i.e. driving.
All I will need to do is switch between each bank in turn whilst the car is under load and I should be able to spot the voltage drop on any bad cells being much bigger than the others, basically just look for the bank that has the lowest voltage whilst under load, pull that bank and test each cell. It just gives me a way to check the cells under load.
Hi. I've been meaning to make contact ever since I saw your ev at the Brighton mini makers faire (2014?). Are you still happy to offer advice to someone (me!) who is interested in building their own ev? I have various vehicles including a 1939 Austin 7 special, and I would love to build my own ev version of this onto an existing chassis. I am a novice in all respects with regard to electrics and would feel more comfortable with lead acid options, but any pointers would be greatly appreciated. My email is jon@metaljon.com if that is easier. Cheers Jon.
ReplyDeleteHello! I've just bought a Beat with the intention to convert it, but wanted to ask about the gearbox strength. From your experience, would you still suggest using the stock transaxle? Is an upgraded clutch enough to handle all that torque? I'd love to hear your thoughts. Thanks in advance! - Sam - mistasam@gmail.com
ReplyDeleteHello Sam, I ran mine for 2 years solid every working day as a daily driver and yes the standard clutch plate I used for the coupling splines was not up to the job and got stripped after around 18 months use, so I would definitly upgrade the clutch plate if you can, never had any gearbox issues though. I would also reccomend going AC motor and controller and keeping the total power output inline with or close to the original spec if you can, if you really want it to go like stink, you would need to loose the gearbox completely and go for a LSD and uprated backend components completly, I wanted to do this but could not afford the expense at the time, I still have it, off road :-( but may upgrade it one day when I get more time. Good luck with the conversion, do you have a blog page of the work you are doing? I would advise doing this as you will meet many folks online that can help, diyelectriccar is the best place to go for all your needs. https://www.diyelectriccar.com/
DeleteBear in mind that I had no clutch as such in my final conversion the clutch plate was just used as a coupling plate between motor and gearbox, I only ever used 3rd and 4th gears and relied on the syncromesh to change gears, just ease off the throttle when you change, you get used to it, would love to have AC motor and controller though to provide regen, and in hindsight I massively uprated the torque (x3) over the original spec, not entirely neccessary (or sensible) but I also didn't look after it as it was just too much fun to drive at high accel/speeds hence the stripped clutch plate, I guess if you up the clutch plate strength you may just push the damaging torque force onto the gearbox and transaxles, so I if I were doing it again I would either opt for an AC motor/controller with power/torque not to much ahead of what the gearbox is designed for or you will be asking for problems, also had major issues with the stock speedo/odometer as it was corrupted by huge magnetic forces magnitising the drive shaft and messing with the signals, would also reccommend a full BMS such as Orion BMS. LVC/HVC is a must but full BMS is much better if you can afford it. I also built the charger (not reccomended) it worked but it was a nightmare to build and get working, I would got for off the shelf charger if again you can aford it.
DeleteI am of course assuming you are using lithium (hence LVC/HVC, or pref full BMS)
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