New EM3EV battery not charging?

Well I'm having another problem.

I let the kid run the bike pretty hard over at the park today...which means bumpy terrain and definitely involves a lot of stopping and then full throttle...ie a lot of high wattage running. More continuous high wattage than I ever do riding on the road. All of a sudden the power died. He only road maybe 2 miles worth (10 minutes) He thought the battery died, but I had around 52 volts of charge when he took it. The controller definitely was a little warmer than usual. I checked the connections and let it cool, slightly concerned he may have fried the controller....but when I plugged the battery in it wouldn't charge.

When I try to turn on my cycle analyst, it attempts to power up but dies again after only 1 or 2 seconds. My battery is only 2 months old and uses the 25r samsung cells...which have an 8c discharge rate if I remember correctly. I have a 40 amp infineon controller which I purchased at the same time as the battery. I run a 1000w yescomusa motor which usually doesnt take a beating the way it did those 10 minutes....but that shouldn't effect the battery itself anyway.

I know this information is vague, but does this sound symptomatic of anything particular??

BMS has probably cut off the battery from the outside world.

Does it have separate charge and discharge connectors?

What's connected to each one, if so?

do you have a voltmeter? measure the voltage at the charge port on the battery.

post up a picture of the charger you use. do you plug the charger into the wall before plugging it into the battery?

can you measure a voltage on the output of the charger? when it is turned on that is.

So how bad was the crash you weren't told about?

Might be something happened that damaged the connections to the charge plug on the battery. Or maybe he killed some spot welds on the pack itself.

do you have a fuse that blew?
did you recheck all your connections?

too bad he disappeared. thought we could help him.

Ok. I'm going to take some pictures in the morning of my battery and the charger to post.

Here are some answers to the questions asked. Thank you for helping.

As an fyi....I did send an email to Paul (Cellman) at em3ev.com...just waiting to hear back from him.

Amberwolf, I'm embarrassed to say I don't know what your asking. The battery does not have a discharge connector. Is that what you're asking? I don't know anything about the BMS itself until I hear from Paul.

dnmun, I do have a voltmeter. I'll take the voltages at the battery's charge port as well as of the charger's output and post the results along with a picture of the battery and charger. To answer your question, I always connect the charger to the battery, and THEN plug in the charger. Is that wrong??

dogman dan...I was waiting for someone to suggest a crash. HAHA. Thankfully I don't have to doubt his word...I was with him the whole time. I'm confident there wasn't any damage to the charge connectors because of how tight they fit between the battery and my triangle bag. This battery pack is really tightly wrapped, so without an actual crash I don't THINK a spot weld problem is the case here. I rode my bike really hard with my last battery, which wasn't nearly as nice as this one....and never broke a spot weld....until I dropped the damn pack. Lol. Even with a few broken spot welds it would still charge.

r3volved....maybe a fuse is possible???? Do all lithium battery packs have them? My pack is still under warranty so I'm not going to open it up until I hear back from em3ev on this...but if that's the only problem that would be awesome. I did recheck the connections...briefly. But the connection between the battery and the charger is definitely fine....and it's not charging.

I shouldn't even give an opinion, but to me either the bms or the fuse seem the most probable.

I wish I could check back in more often, but I leave the house between 10 and 11:30 every morning and don't get home from work till after 10pm each night (EST.)

I really appreciate all of your followup questions. Please check back and help in any way possible.

My bike is my commuter vehicle...THANKFULLY I convinced my roommate to get an ebike as well....which he just got and set up last week. Perfect timing. He's letting me borrow it for awhile. HAHAHA.

getzbuzy said:

Amberwolf, I'm embarrassed to say I don't know what your asking. The battery does not have a discharge connector. Is that what you're asking?

Click to expand...

My EM3EV pack has a charge connector to plug the charger into, and a separate discharge connector to plug the controller into (this also has a precharge (white) pin but I don't use that).


At least some batteries with separate ones like this will internally disconnect the discharge connector once any cell drops below the LVC (low voltage cutoff). At that point only teh charge connector will show the battery voltage anymore, and will only charge thru that connector at that point (normaly you could charge thru either, but if ti has separate ones it may be better to always use the one for charge to do that).


As for fuses: my EM3EV pack has one, shrinkwrapped to protect it but it's on a separate (deans?) plug.

you just need to look for voltage of the battery at the charging plug on the battery. if you don't see voltage at the charge port then it is disconnected from the battery which prevents the battery from charging, which was your original problem.

there can be several reasons so you then have to systematically isolate the cause.

yes, always plug the charger into the AC first and then plug the battery in after the charger is turned on.

Good there was not crash, so it's not likely a problem inside. Just the riding hard over rough terrain could still have popped a flaky wire loose on a plug, so look at the plugs real good as the starting point.

See if there is volts on the battery side, then see if still volts on the charger side. If yes to both, theoretically when you plug in, a connection is made. Assuming no damage to connector contacts.

I'm more confused than ever.

After my post here last night I went outside to disconnect the battery so I could take voltages and post pictures. I decided to give it one more shot at a charge....and it worked. I didn't knowingly move any connectors or anything. Just plugged 'er in. I tried at least 5xs the night before to get the battery charging without success. Each time leaving it plugged in with hope that it would "kick on" after being plugged in for awhile (30 minute minimums.)

Anyway, my ca v3 showed 52 volts..full charge is almost 59. I took it up the road at a 28ish amp setting, but after 50 yards or so I toggled my 3 speed thrrottle to 100% (40amp) and, unlikely by coincidence, my ca immediately shutdown stating low voltage.

I let it charge to 100% overnight, and this morning I rode it for 3.5 miles without problem. To the best of my memory, the voltage drop and ah used seemed relatively normal. I rode it full throttle at 20amps, 28amps, and 40amps..hitting a top speed of 32 between stop signs. When I have a little more time, and have someone available to pick me up if it shuts down, I'm going to attempt a normal 17 mile ride to see if it once agains shuts down when the battery approaches 52 volts.

Another concern is just how hot the controller was after a 3.5 mile ride. I've never felt it after such a short ride so I don't have a basis of comparison, but its pretty hot. As long as I have my ca delivering no more than the 40amps that the controller is rated for do I ever need to be concerned?????

amberwolf.....im going to disconnect the battery tonight and post a pic so you can see the battery.
dnmun....good to know. Can you tell me why the charger should be plugged in first? In my head I figured by connecting the charger/battery FIRST it would be better for the battery. Never really gave it much thought though.

Well I found the problem. It was extremely obvious after I took apart the bike. In my excitement of setting up my new system, my dumbass forgot to remove the water bottle cage mounting bolts. There is not much padding on my triangle bag down the seat post area and everytime I hit a bump those bolts were banging into the BMS of my battery pack. Fortunately the damage was not too severe. I took the bolts out and wrapped the battery pack in foam. It's been working great ever since. I decided to post some pictures hoping and they help someone else in the future. Thanks for all your help.

I use mono kote the stuff you get at a hobby shop to cover RC airplanes with it comes in any color you just iron it on you battery pack water tight .

getzbuzy said:

Another concern is just how hot the controller was after a 3.5 mile ride. I've never felt it after such a short ride so I don't have a basis of comparison, but its pretty hot. As long as I have my ca delivering no more than the 40amps that the controller is rated for do I ever need to be concerned?????

Click to expand...

Are you sure it's rated at 40A? Normally, if it's marked 40A, that's the maximum current. The rating is half of that, so if you run continuously above 20A, your controller will get hot, and continuously at 40A, something will burn.

Hmmmm.

Never knew that. I got this controller from em3ev when I bought the battery. Here are the specs...

Specification:
• 12pcs of Genuine IRFB4110 Mosfets. Just about the best 100V TO-220 Mosfet available
• 100V Caps, Max input voltage is limited to 90V
• 36-72V operation, 90V max
• 40A Current Limit
• 4mm2 (>11AWG) High Temperature Silicone wires used on Phase and Supply cables
• Dimension: 180 * 85 * 45mm
• Weight: 0.54kg


Although I do draw a lot of amps to get up to speed, I want to say I run continuous in the high teens (13 to 19?)
I have a CA3 in my setup. I'll have to pay closer attention to that.

It definitely gets warm....but not nearly as hot as it was the day I had that incident.

So ALL controller "current limits" are really only rated for 1/2 of that max on a continuous basis?

There is no hard and fast "standard" of how parts are marketed.

Some of them may have ratings marked on them or advertised on the seller's site that are higher than they could stand to be run at more than just a moment, and some of them may be marked for ratings less than their maximums, some of them for ratings that are an average they could run at all day long, and probably everywhere in between. Some are probably even marked as a low wattage controller to make it "legally sellable" in some area, when in fact it isn't limited anywhere near that far down.


So if you wanna know what is actually happening, you'd have to watch a wattmeter or ammeter (and preferably one that logs the highest current draw as well as the lowest voltage, so you can get an idea in tests what the actual wattage drawn might be by multiplying those two).


FWIW, I expect EM3EV's stuff, like Grin's would be marked with actual ratings, so a peak or max current rating would be just that, the max it would actually ever pull.



Most of the controlers I've had that specify a current limit, and havent been modified, actually are very close to that for peaks.

What they could take constant, I don't know, as I've not loaded mine down that much for that long.

Some of them don't even pull the current they *should*, when loaded to max (like the ones on the trike, one of them I got to pull about 40A once, but almsot always only 33A or so max no matter how badly I load it down).



I note you mention you think your sustained current is in the high teens--that is a lot of current. Even my setups (trike or bike) at 20MPH with dual motors don't pull that much after I am done accelerating (can easily pull 80A on CB2, and 60-65A on SBC, during accel). IIRC it's more like 7-10A at most for cruising, at least on the flats.