72 volt cut out???

[mikebikerad]

My 72v has been up and running for two weeks. It is comprised of the following
- two 36v 10 amp/ hr ping packs V1
- 72 volt 30 amp old school e-crazyman controller.
- 30 amp fuse protection on each pack
- amped bikes rear wheel kit.

It was running great for the first week and then for the last week it has been cutting out more frequently. It started cutting out after 7 or 8 miles and then a few days later at 3 or 4 miles. now it won't turn on?? I've checked all of the connections. What would you check next? this thing flies! when its running

Thanks for the help

mike

 

[Russell]

this thing flies! when its running

Out of curiosity how fast was it when it worked?

Oh and this is what ebikes.ca says about running the Nine Continent motor at 72V.

Can the motor run at 72V?

The answer is of course yes, with a different controller the motor will run at 72V if a high RPM is required, but unless due care is put into ensuring that the actual motor current is regulated to a safe level there is a likelihood of causing the motor to overheat. We have selected the motor windings so that 72V will not in general be required. 36V will give enough speed for most people and 48V would be an option for those that really want to go fast. Check our motor simulator for details.

-R

 

[Drunkskunk]

did you mod the BMS to run in series? the V1s took a bypass diode to keep from blowing out, IRRC.
30 amps on the early ping packs was more than they could handle for long periods, so you might have fried some cells.

 

[dogman dan]

Isn't 30 amps 3c on a 10 ah ping? He could be having motor problems and battery problems. I suspect battery cell damage. v1 ping is a 1c cell or if pushed, maybe 1.5c . He may be pulling only and actual 20 amps, but even that is high for a v1 ping.

 

[mikebikerad]

I never modded the Bms's . I didn't know that it was necessary. The pack voltage is right around 74 volts now charged when before these issues it was settling closer to 78 volts. Its top speed was 45 mph flat ground no peddling when it was running. please help. I need speed

 

[John in CR]

45mph out of 10ah v1 Pings is asking a lot. Are you bypassing the BMS's for running? It sounds like your issue has changed gradually, have you been letting them properly balance during charging? ie Letting them charge overnight until the charger stops turning off and on intermittently.

Also, is Ping still using 12 series for what he calls the 36V packs? I have a pair of 36V15ah v1 Pings that I run in series with an original E-crazy 72V30A controller, but my Pings are more like 84-85V at full charge from my Ping chargers, which occasionally is too high for the E-crazy controller to turn on correctly.

Yes, you need to add the diodes to run them in series. That prevents one BMS from getting fried when the other BMS trips and turns the pack off.

John

 

[mikebikerad]

I have been letting them fully charge and yes the pack has been getting to around 85 volts overnight. It sounds like we have the same old ecrazyman controller because my controller wasn't turning on fresh of the charger. I had to turn it on and off for a few minutes. I don't know how to find diodes correct for this application. Will the diodes fix my problem or was their absence in the first place probably what fried something in the packs. what should I do next?

 

[mikebikerad]

li just sent me an email. the packs are 2c continuous.

 

[Russell]

See this post;

http://www.endless-sphere.com/forum...70490&hilit=lithium+packs+series+diode#p70490


-R

 

[John in CR]

The fresh off the charger issue, is a voltage limitation of the controller. That solution is to just run a bit of juice off of the pack. There's not much capacity in the first couple of volts, and I used to just connect an ordinary light bulb for a minute or so.

The diode protection is simple and done on the battery mains as discussed in the thread link above.

Regarding the cutouts, did it require disconnecting the battery to reset? If so, that was most likely the BMS's tripping due to over current. If it won't come back at all now then that may have blown one of the BMS's with the unprotected series connection of packs. I bypass my bms's for running, but there is some risk with that through too high a discharge rate reducing the life of your cells, AND you have to be sure not to run your pack too low, which can shorten their live to zero. I'm pretty conservative with mine, so I accept the cycle life risk to avoid the tripping BMS aggravation. The bigger issue if a BMS is blown is charging, but worst case you could use the good bms to balance each pack, while you buy a new BMS from Ping. Just alternate which one gets balanced daily, so each one gets balanced every other day, should be fine. Just be careful not to damage that ribbon cable or it's connector. You'd also need to add a few connectors to make the switching simple.

Talk to Ping.

John

 

[Drunkskunk]

I never modded the Bms's . I didn't know that it was necessary. The pack voltage is right around 74 volts now charged when before these issues it was settling closer to 78 volts. Its top speed was 45 mph flat ground no peddling when it was running. please help. I need speed

45mph on 10Ah Pings, there's your problem. Very likely, you have damaged or blown one or both BMS without using diodes, but that is only a minor problem. BMS can be replaced. 45mph and a 30Amp controller means you were likely pushing these batteries to 150% capacity often. they just can't handle that, Very likely if you are only able to charge up to 78 volts, you have already fried some cells, and the rest will likely have short lives from now on, even if treated well.


If you want to go fast, you're going to have to get batteries that can handle it. A123 cells should work, Or RC Lipo, or Ping's 24Ah battery packs.

 

[fechter]

If the BMS blew due to lack of diodes, the most likely failure mode is for the FETs to be shorted, which will still allow the pack to discharge, but the LVC and overcurrent functions won't work anymore. There should be a way to test it.

I'd be more inclined to think the cells fried due to high discharge current. This typically causes the cells to 'puff up' a bit.

After charging, remove the charger and try to measure the individual cell voltages. Bad ones will be low.

 

[Knuckles]

A life spent making mistakes is not only more honorable, but more useful than a life spent doing nothing.
George Bernard Shaw (1856 - 1950)
More Mistaken Quotables here ... http://www.quotationspage.com/subjects/mistakes/

WELCOME TO THE CLUB MIKE!

Dang ... If you only checked in with me first (or any number of folks here in the forum).
It would have saved you some serious heartache.

45 MPH with the original 30A PIC crazy controller? WTF!
No bypass diode on the ping BMS's ... You Bad Bad Boy!

 

[mikebikerad]

It sounds like this may turn out to be a costly mistake. I guess that I got a little ahead of myself in the pursuit of speed.

 

[John in CR]

It sounds like this may turn out to be a costly mistake. I guess that I got a little ahead of myself in the pursuit of speed.

It's probably not so bad, and you just need a new BMS. I'm a risk taker and don't like those BMS trips anyway, so I'd bypass the BMS's and try to stay within the performance levels already experiences with a bit more care up hills and into headwinds, and try to stay away from prolonged WOT. Then just use the good BMS to balance each pack a couple of times a week during charging. You do want to make sure the LVC on the controller cuts out before the packs get too low.

John

 

[mikebikerad]

So... I took the batteries off and sure enough one of the packs is reading 24.9 volts and the other 42 volts. Ping told me that it is probably not as bad as it seems and that I just need a new BMS. I'm having one sent out in a few days and I will report back my findings. thanks to everyone. next time I might use some diodes or more appropriate batteries.

 

[Knuckles]

Mike ... TIME to buy a soldering IRON perhaps?

"A boat is just a hole in the water that you throw money in" (unless you are a MASTER of your vessel).

"An eBike is just a hobby" (unless you are a MASTER of your E-Vehicle).

Owning an EV demands that you MASTER ...
1) Battery Chemistry
2) Pulse Width Modulation
3) Basic/Advanced Wiring
4) Riding and Operational SKILLS
5) A Thurst for Technology

 

[Drunkskunk]

Mike ... TIME to buy a soldering IRON perhaps?

"A boat is just a hole in the water that you throw money in" (unless you are a MASTER of your vessel).

"An eBike is just a hobby" (unless you are a MASTER of your E-Vehicle).

"Baiting a hook is just a way to feed fish." (unless you are a MASTER of baiting).


Or you can ask 9000 questions here and learn from others misfortunes... errr, I mean experiances.

 

[Knuckles]

MASTER of baiting

You need a WOMAN! Hubba! Hubba!

[youtube]BNyrnNto-xU[/youtube]

 

[docnjoj]

Wouldn't they just call U a Master Baiter! I once played for an industrial league team called the Master Batters! Word!
OtherDoc

 

[mikebikerad]

Good News, kind off.

Checking the voltage of individual cells in the ping packs showed that one of the 36 volt packs had 4 bad cells reading between 0 and .5 volts. Luckily, the other pack was fine because the bms must have only tripped on one pack. Ping Express shipped me replacement cells and I replaced the 4 bad 5ah cells. Now I used each of the packs separately on two lower powered bikes (36 volt 20 amps). Now a few 20ah pings are in the mail for a new "diode protected" high voltage e-bike.

 

[nineball]

Sounds like you need to add a switch or relay to give you the boost your looking for 36/72, so you can conserve the motor,controller, and batteries, the rest of the time, also you need to get bigger batteries (AH) Your sucking the amps out twice as fast with your new set up, and fat (10g) wiring to handle the load. From what what I have been reading, I'll bet your running a 36v controller on 72 volts, which is set for low voltgage cutoff (lvc) for a 36v setup....which is now sucking the life out of your batteries because it's not cutting off at the right volts for 72v. You need to add a 36v lvc to each pack, (please somebody correct me if I'm wrong), The raw power/speed is great...but there is allways a price to pay for it.

As you try to go faster....the values trying to stop you add up twice as much..so it takes 3 times the power to go 1/2 again as much.

 

[mikebikerad]

My old 72 volt controller has an LVC OF 56 volts according to Knuckles. I just ordered two 15 amp hr packs with a BMS that doesn't have lvc cutout but instead an alarm function. Sweeeettttt!

 

[nineball]

That should do the job, what batteries and voltgage?

 

[Anonymous]

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