WE BD36 is shutting off when load is applied-Help!

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gallodp
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I have a 48volt lithium batt into a crystalite 48volt 30amp controller into a WE bd 36 26" wheel and when i put any load on it the controller cuts out and needs to wait 15minutes before it will work again but it does the same thing. I had a 36volt controller on there and it was working fine for almost a year and is only recently that it started acting up. When I replaced with the 48volt crystalite I thought I had solved the problem but the exact same thing happened which makes me think it is something in the wheel or Amps or I dont know but it is soul crushing to not be on my bike. The other thing that happened is that i replaced the brushes and brush holder and maybe the timing is off? Would the effect of off timing be a shut down when load is applied?How do I know where the right timing is?
Please Obi Wan your my only hope....

WE BD 36 is shutting down with Load applied

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reikiman
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Re: WE BD36 is shutting off when load is applied-Help!

Are you sure it's the "controller" that's shutting down?

I've seen a behavior with lithium batteries where the BMS board shuts down the battery when the current draw goes too high. The BMS is there to protect the battery pack, and one thing the BMS protects for is too high a current draw.

What is the specified amp capacity of your battery pack?

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gallodp
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Re: WE BD36 is shutting off when load is applied-Help!

how would I know? It came from japan and is duct taped together all crazy looking. what could I use to make that measurement?The other thing is that the bike has been running top notch for the past 8 months or so. This problem is recent.
thnx

reikiman
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Re: WE BD36 is shutting off when load is applied-Help!

The previous controller was how many amps? e.g. a 36v 30A controller will have a max of 1080 watts while a 48v 30A controller will have a max of 1440 watts. Hence at 48 volts the controller will draw more watts than the previous 36 volt controller.

One way to make measurements - what I do - is to use the 'WattsUp' meter you can get via BatterySpace.com and connect the battery pack through the WattsUp to a big variable resistor. I vary the resistor to get different discharge rates and see how the battery pack behaves separately from the rest of the system. By 'big' I mean one that can handle 300 watts or more, the one I have is maybe 8 inches in diameter, a very 30's look to it, and is made by Ohmite.

I suggest getting the WattsUp regardless but maybe getting a big variable resistor isn't within your means.

It occurs to me if you connect up a light to the battery along with its connection to the controller .. if the light remains lit it means the battery is not cutting out and instead it's something to do with the controller.

A question is:- is the controller getting hot? It's plausible there's a high temperature cutoff in the controller.

__________________

- David Herron, Green Transportation Examiner, Green Transportation Info, The Long Tail Pipe, Electric Race News, davidherron.com, 7gen.com, What is Reiki
- Charger bike (rebuilt), Electrified Electra Townie, 1971 Karmann Ghia

gallodp
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Re: WE BD36 is shutting off when load is applied-Help!

there is not time for it to get hot. I can only go a couple of blocks. Plus i did touch both the wheel and the controller and its not hot.here is the battery i bought one year ago- 48V 20AH LiFePO4.
I noticed today that while I had the wheel off the ground(on the kickstand) and gave it full throttle that there was a rhythm happening. it was not constant. the sound was 3/4 constant then a lull and it repeated itself with consistency. so every couple of seconds there was this dip in power.
Both controllers were 30amps.
frustrating! The 36volt and the 48volt controllers are both responding the exact same way, although remember the the bike was working fine and smoking fast for the last 9 months.
Do you know what the effect of having the timing off would be?
thnx

dogman
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Re: WE BD36 is shutting off when load is applied-Help!

my guess would be something wrong with the battery. If it's an 18650 round cell type pack from ebay you most likely have some dead cells in there that are causing low voltage and low capacity. Those less expensive packs have a reputation for broken connections inside, or just weak cells in there that drag down the others till they die too.

Checking the voltage of each cell group can often show where the bad cells are. Checking the voltage of the whole pack while the wheel is spinning can show if voltage drop under load is severe.

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