OK, straight to the point..... I have an XB600 that I have upgraded to 60V with the controller "shunt" mod performed.
All seemed to be going fine, then one day after about 10 miles it died on me. I opened up under the seat to check things out.... Well I first noticed the 20A fuse holder had not only blown the fuse, but had also melted the one whole side of the fuse holder. So I bought and replaced it with a new one, upping it to a 30A fuse and holder. Once again all seemed fine but I dont think i ever rode it much over 10 miles.
Well yesterday after riding about 7 miles it "ran" out of juice again, so I opened everything up again to check..... The 3 phase wires to the motor had melted and were almost fused together, mostly the yellow one. I checked the pack voltage... 63V yet the "fuel" gauge was down to 3/4 (ps. I never modified it to register for 60V). My question is this..... What would make the bike show a low pack voltage and cut out like that when the pack is perfectly charged? I have checked each of the 2 month old batteries in the pack and charged individually, all checked out fine. Is this most likely something wrong in the controller or the motor? I would like to have a plan of attack before I take everything completely apart. The weird thing is, from a full charge, about 68V, it runs fine and acts perfectly normal until it hits about 63V (around 7-10 miles), then it acts like it is starving for voltage.
Any ideas anyone??
If it ends up being the controller I might just end up getting a new 72V one and adding a 6th battery in the mean time. I guess if I do that I might end up replacing all the wires from the controller to the motor with higher gauge ones, hell I might as well replace ALL the wiring at that point too!
Merry Xmas. It sounds as if you are hitting the low voltage cutoff of the controller. The controller starts to shut down to save the batteries from discharging to low, but that controller is a 48v so the LVC should be like 40v or so. I can't see how it would be the motor if it runs fine at 68v. Have you tried hooking it back up to just 48v?
My guess would be the controller. It could be that you are pulling alot more amps from the controller now than before. You might open it and take a look inside. If you shorted the phase wires and the fuse I would think it it delivering more current than before which could be draining the batteries faster. Is the bike quicker from the starting position than before? Not really sure what else it could be besides the controller.
How did you wire your 5th battery in? It should register across the voltage gauge if it is in series with the rest.
Yes I have tried just the stock 48V and it barely moves. And before all this happened the voltage gauge never moved off the peak spot on the H. Considering it is the controller that adjusts the voltage gauge on the dash I would guess I fried a mosfet and capacitor or 2 in the controller. I just wanted any info from someone who might actually know before I end up removing the controller and going through all that work etc. and if its the motor, that would suck to take out the controller and all that checking for nothing..... I would have to assume though, that since it works perfectly fine with voltages 63 and up that the motor is just fine and it is the controller. Also, when I tried it on the center stand with no load on the motor it worked a lot better.
Looks like I will be taking the controller apart in the very near future :( If I fried the caps and or mosfets I guess I might as well upgrade them to the higher voltage ones when I replace them, at least then I have the option to go 72V if I want.
PS. the 5th battery is hooked up to the + lead off the main pack, then to the controller input through the 20A blade fuse.
Dave ; Tennessee
XB-600.
Well, I hope it works out for you. I looked at the schematic on the xb600 and it appears to me that the voltage gauge is wired to the blue wire from the controller. The orange wire from the controller outputs the same voltage to the keyswitch as the battery pack voltage. Then the keyswitch connects it to the blue wire. So wouldn't the voltage gauge be reading the true battery pack voltage? I am not quite sure how your 5th battery is wired. It sounds as if you wired it in between the controller and the main battery pack I wired mine by cutting the last negative lead wire of the original 48v pack and wired it to positive on the 5th battery then attached the 5th battery negative wire back to the original negative ground wire.
As you probably know I have since wired in a 6th battery and have been running at 72v for well over 300 miles now. If you do change the controller You might think of getting the e-crazeyman controller that is good up to 84v. It has worked well for me. If the controller is working properly at 68v how can it have a bad cap or mosfets? Don't the mosfets basically turn power on and off. If one is bad would it work properly at any voltage? If you want to measure the controller to see if it working properly couldn't you measure the no load current on center kickstand. It should be below 2amps. Just some thoughts. Good Luck.
Its very weird... once again I fully charged it to 68.xV and once it got down to 63V (I know this because I checked the pack voltage as soon as it started to die again) the voltage gauge dropped rapidly and it started dying. I am thinking there is something messed up inside the motor itself. That is the only viable reason I can think of that would make it only run with 64+ volts. Perhaps there are some windings ruined and only the higher voltage with make it work? On the center kickstand with no load it seems to do fine when under 63V so perhaps that confirms my belief? I doubt it is a problem with batteries since they are only about 2 months old, when fully charged each reads about 13.5V and when the pack is down to 63V they each read at almost 12.5V exactly. Is it me or should the pack not drop from 68-63V so quickly after only 5 miles or so or is that normal?
Looks like I will probably have to take the damn motor apart, so any advice as to what to look for or how to fix it would be greatly appreciated as I have never actually taken apart a motor. I have always just replaced them...
Dave ; Tennessee
XB-600.