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Need help with Razor MX-500

9406 Views 6 Replies 4 Participants Last post by  bassiclyloudog
I have a Razor MX-500...had it a few years. Ended up moving and leaving it sit in storage for about a year. It had a full charge when first put in storage...and it ran great. Pulled it out of storage...and its dead. The low battery light was on...and it would click when you turned the throttle, but it wouldnt move. Ok...dead battery...no big deal...but I couldnt find the charger for it. So I took the charge plug off my Razor Pocket Rocket, wired it to the MX-500...and tried using the charger from the Pocket Rocket. It wouldnt charge. So I ordered a new...and correct...charger for it, wired the original charge plug back to it and let it charge for 2 days. Unplugged it...and nothing. The power light is on, the low battery and full battery lights are not on...it no longer even clicks when I twist the throttle. ***?!?!? I did check and change the 30 amp fuse. So Im left sitting here, scratching my head, wondering whats wrong with it and if it can be fixed...without costing me an arm and a leg. One friend said its probably the batteries re shot from sitting. Another said its probably the control module. Does anyne have a more educated guess? Any advice would be very helpful...cuz my nephew is driving me nuts and I cant afford to go out and buy him a new one.
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Do you have a VOM? Checking battery voltage and continuity could give a few hints.

FWIW: Sounds like a few dead cells in your battery<s>. Your controller may have under voltage protection to shut off power before the batteries get drained too far. i.e. a 24V system will shut down at 20V or a 36V system will shut down at 30V.

With no drain the system may have been just over the minimum voltage and as soon as you turned on the throttle, the motor clicked, drew a bunch of amps, voltage dropped below minimum, system shut down.

Dead cells are a chemistry thing. For example, lead acid battery use lead oxide and lead metal with a sulfuric acid electrolyte. When the battery gets fully discharged, insoluble lead sulfate forms which more or less kills the battery. Just about every battery type has its own mode of failure. Anytime you leave a battery alone for over 2 weeks you run the risk of premature death.

The more bad news is: You should never charge a system with a dead cell. What happens is the bad cell can act like a dead short so instead of a 24V battery pack it is now a ~21.9V battery pack. Your charger still tries to charge your battery pack to 24V so it over charges everything and cooks the batteries that are left.
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The batteries are toast. Can't let them sit, have to keep at close to full charge at all times or re charged right away after use. Plus you cannot run the batteries till the bike barely moves, those are all battery killers.
****...that sucks. Im not gonna drop another $130 plus into it for new batteries. To be honest, I can afford that. I do have a volt meter...Ill check them. If the batteries are truly toast...as its sounding...Ill try to sell it for parts. If nobody wants it...to the dump it goes.
Thread hijack warning!

Has anyone here tried banks of these? http://www.ebay.com/itm/Brand-new-12V-6800mAh-Li-ion-Rechargeable-Battery-Pack-AC-Charger-Bike-Lamp-/400299659501?_trksid=p5197.m1997&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D16%26meid%3D2182881147377412141%26pid%3D100016%26prg%3D1006%26rk%3D1%26sd%3D230806115118%26

I'm thinking maybe 4 of these wired parallel/series for 24V would put out just enough juice to be viable for a bike I am building for my youngest grandson. Specifically I would rather have a system that could cycle a couple of hundred times and wouldn't involve lead, cadmium, or sulfuric acid.
It's says 12v 6800amper hr, that alot my batteries are like 5 to 7 amper hour. I would ask Cam2, he is much better at electric stuff than me,lol.
I find the 6800 amp hr in that small of a battery had to believe, might be more like 6 amper hr.
well 12ah batteries are around $30 ea so you're looking at $90, $110 with shipping max. which is close to $130, but it is what it is. If you kin want to ride it, and the batteries are maintained you can get 300cycles o more out of them. that's a years worth of riding. Some claim to get 3yrs out of thiers.
you could try a less ah battery. home depot sells smal 5ah batteries cheap. but a new MX is like $300+
at either rate i can't see the controller being the problem.
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