jateureka
10 kW
dogman said:
+1
Battery Fuses blowing frequently
- Thread starter medusa569
- Start date
+1
medusa569
100 W
dnmun said:
I can't find any more info on the batteries used for the eZee other than 10ah. The fuse was hot enough to be able not to hold it. I don't know what the voltage reading was as I didn't have the watt meter hooked up at this time. I will try and do more trests runs in the run where I can strain the bike and try to keep a cnstant eye on the meter to see when it blows.
medusa569
100 W
So what are you guys saying? That a controller rated for 36volts /25A is not the right controller for my battery with 30amp fuse and 500w motor??
I bought the specs on the new controllers that weer the same on the old one that came with the original package when I bought it. what kind of specs should i be looking for in buying a controller then? Can the ones I have be altered?? I noticed on the original infineon they really beefed up the bridges going to the mofsets. I don't know if the new ones were equally beefed. I'll see if I can't get some kind of info storage to save the watt meter info so I can analyze the readings.
medusa
I bought the specs on the new controllers that weer the same on the old one that came with the original package when I bought it. what kind of specs should i be looking for in buying a controller then? Can the ones I have be altered?? I noticed on the original infineon they really beefed up the bridges going to the mofsets. I don't know if the new ones were equally beefed. I'll see if I can't get some kind of info storage to save the watt meter info so I can analyze the readings.
medusa
dogman dan
1 PW
Well, 25 amps is not as bad as 30. I thought you just said you had a 30 amp controller.
In my opinion, it is pushing it a bit, to use that battery with more than a 20 amp controller. It would also depend on how you are riding it. You could be riding a route that never requires more than 12 amps, or you could be pulling 20 amps or more the whole way. Just depends on what your real world load is.
Knowing what your real world amps rate is, can be priceless. It's why we call a cycleanalyst a cheap investment. Knowing your watts or your amps helps a ton for knowing you have set up the bike correcty, for your controller, your motor, your battery, AND you riding it.
Since we still have more than one variable in play here, we can't definitely say much. But my guesstimate is that you have two problems, each from a different cause.
Fuse blowing, and hot fuse holder.
Chances are, you pull 25 amps just enough to get the fuse hot. The fuse holder also makes an imperfect connection, that causes resistance. So your fuse holder is actually causing heat to flow into the fuse itself. This resistance also means that if you draw 25 amps on the controller, plus you have 5 amps of resistance at the connection, including all the other connections on the bike, BINGO you now are drawing over 30 amps and the fuse blows as it is supposed to.
Battery shutdown without the fuse blowing.
This is different, you simply have emptied the battery and now the battery bms shuts off the battery. If you are drawing enough to blow that fuse, you are murdering the battery with high amps, and have been for awhile. The battery is not liking it, and will have lower capacity any time you draw amps out of it faster. Possibly, you have worn it out early.
One last question, was the battery and motor and controller sold to you as a complete kit? If so, by who? I could be wrong about your controller being too big. That is strictly my own opinion, and I am quite conservative about it because I happen to have a really big hill that I have to climb every day. I am not completely familiar with the specifications on your particular battery. But one thing we've learned here about battery size, it's good to double it.
Lowering the amps can be done a few different ways. One is to clip out one of the shunt resistors. But that's pretty drastic. Your motor and controller are a good match I think. It's just that you may have a battery that, in it's current condition, is not as able to stand it as when it was new.
In my opinion, it is pushing it a bit, to use that battery with more than a 20 amp controller. It would also depend on how you are riding it. You could be riding a route that never requires more than 12 amps, or you could be pulling 20 amps or more the whole way. Just depends on what your real world load is.
Knowing what your real world amps rate is, can be priceless. It's why we call a cycleanalyst a cheap investment. Knowing your watts or your amps helps a ton for knowing you have set up the bike correcty, for your controller, your motor, your battery, AND you riding it.
Since we still have more than one variable in play here, we can't definitely say much. But my guesstimate is that you have two problems, each from a different cause.
Fuse blowing, and hot fuse holder.
Chances are, you pull 25 amps just enough to get the fuse hot. The fuse holder also makes an imperfect connection, that causes resistance. So your fuse holder is actually causing heat to flow into the fuse itself. This resistance also means that if you draw 25 amps on the controller, plus you have 5 amps of resistance at the connection, including all the other connections on the bike, BINGO you now are drawing over 30 amps and the fuse blows as it is supposed to.
Battery shutdown without the fuse blowing.
This is different, you simply have emptied the battery and now the battery bms shuts off the battery. If you are drawing enough to blow that fuse, you are murdering the battery with high amps, and have been for awhile. The battery is not liking it, and will have lower capacity any time you draw amps out of it faster. Possibly, you have worn it out early.
One last question, was the battery and motor and controller sold to you as a complete kit? If so, by who? I could be wrong about your controller being too big. That is strictly my own opinion, and I am quite conservative about it because I happen to have a really big hill that I have to climb every day. I am not completely familiar with the specifications on your particular battery. But one thing we've learned here about battery size, it's good to double it.
Lowering the amps can be done a few different ways. One is to clip out one of the shunt resistors. But that's pretty drastic. Your motor and controller are a good match I think. It's just that you may have a battery that, in it's current condition, is not as able to stand it as when it was new.
dnmun
1 PW
the little turnigy wattmeters and the cycle analyst will record the peak amps. you have to check it before you disconnect the wattmeter from the battery. they are really useful for figuring out after the fact when something happens. looking for peak volts or low volts on the display after it fails for some reason.
dogman dan
1 PW
Reading back the whole thread,,,,
Did you ever get a real world amps reading, or a real world watts reading, for when you start the motor from a dead stop?
Cruising will be not much above 800w,, or about 20 amps of 40 actual volts. Or less. What's your actual max amps?
What I'm fishing for here, is finding out what amps your controller actually is, vs what it is thought to be. Maybe you got a mislabled 30 amp controller?
Did you ever get a real world amps reading, or a real world watts reading, for when you start the motor from a dead stop?
Cruising will be not much above 800w,, or about 20 amps of 40 actual volts. Or less. What's your actual max amps?
What I'm fishing for here, is finding out what amps your controller actually is, vs what it is thought to be. Maybe you got a mislabled 30 amp controller?
999zip999
100 TW
I got a 40amp controller that set to 25amps it should have been a 40amp., he replaced it. So it could happen the other way around just a sticker. I like the extra resistance in the fuse holder and controller spikes ect. We are still quessing ?
jateureka
10 kW
According to this post, their KU123 controller is allowing 38A current draw up hills http://endless-sphere.com/forums/viewtopic.php?f=2&t=37853
& there's info there on limiting the current draw.
& there's info there on limiting the current draw.
medusa569
100 W
Well I went riding the other day and tried the best I coukd to keep an eye on the meter..I think that is the problem...the motor or controller is cutting off at 30A.
since it was in the beginning of the trip I knew it shouldn't be overheated but I didn't pedal as much uphill so as to "stress" it and see if it'd cut off and it did. The last glance down it was showing over 29 amps..so I"d bet it reached 30 and shut down. I reset the bayyrtu and kepyt right on going. It's jusy a big annoyacne to have to reach around and keep doing that. It gives a less than sec ure feeling. But as the label on the controller said overcurrent 30a. Maybe that means it cuts off at 30 amP? Does the controller have to have the same cutoff value as the battery fuse??
since it was in the beginning of the trip I knew it shouldn't be overheated but I didn't pedal as much uphill so as to "stress" it and see if it'd cut off and it did. The last glance down it was showing over 29 amps..so I"d bet it reached 30 and shut down. I reset the bayyrtu and kepyt right on going. It's jusy a big annoyacne to have to reach around and keep doing that. It gives a less than sec ure feeling. But as the label on the controller said overcurrent 30a. Maybe that means it cuts off at 30 amP? Does the controller have to have the same cutoff value as the battery fuse??
jateureka
10 kW
Sounds more like the BMS in the battery is tripping.
Most of the 10Ahr eZee batteries I've seen are rated for 2C = 20A, which matches the eZee controller current limit.
At 30A draw you are using 30 x 36 = 1080W, instead of the 350 - 400W that battery is designed for. While the battery was young/fresh it may have been able to handle that but as it has aged and been over drawn it can't.
Most of the 10Ahr eZee batteries I've seen are rated for 2C = 20A, which matches the eZee controller current limit.
At 30A draw you are using 30 x 36 = 1080W, instead of the 350 - 400W that battery is designed for. While the battery was young/fresh it may have been able to handle that but as it has aged and been over drawn it can't.
999zip999
100 TW
I agree.
dogman dan
1 PW
There you go. It's a 30 amp controller I'd never recomend for use with that battery. The battery has been stressed and now the bms is tripping sooner and sooner under load.
You just have too much motor for the battery. It worked for a while, but now the battery is showing the effect. Time to get yourself some A123's or RC lipo.
You just have too much motor for the battery. It worked for a while, but now the battery is showing the effect. Time to get yourself some A123's or RC lipo.
dnmun said:
A Cycle Analyst is a worthwhile investment anyway - order one up straightaway. While you're waiting for your new batteries to arrive and get installed, install the CA and set the current limiting so you can get some use out of your present setup without the cutout problems. It should run about the same on the flats (except for flat out WOT) but will just wimp out on the hills instead of driving the battery into the ground. It will essentially turn your 30A controller into a 20A one.dogman said:
When you do get the new batteries installed, you'll be ready to limit/monitor from the start...
dogman dan
1 PW
That would have been exactly the thing to do, use a dp CA to limit current and avoid murdering the battery in the first place.
Unfortunately, the battery is now very likey done for.
Buying a DP CA will be a good step in the right direction if a similar amp rate battery is bought as a replacement. If, that is, the controller is a dp compatible model.
If the controller is not DP compatible, a stand alone CA is still a priceless tool for monitoring what you are actually doing to your next battery.
Unfortunately, the battery is now very likey done for.
Buying a DP CA will be a good step in the right direction if a similar amp rate battery is bought as a replacement. If, that is, the controller is a dp compatible model.
If the controller is not DP compatible, a stand alone CA is still a priceless tool for monitoring what you are actually doing to your next battery.
dnmun
1 PW
it may only be one cell that is dead. he might be able to buy a replacement cell and get more power again.
fuse holders melt because the contacts where the fuse clip is crimped onto the wire is usually just totally inadequate to handle the current so the fuse holder melts from the heat even before the fuse blows.
i liked the idea that bob had of just soldering the main wire onto the fuse legs. use a big fuse to start with so it takes something like a real short to blow it. say 70A, then after you solder the legs to the wire, use some of the insulating sheet stuff used in the batteries to separate them from the case, put that on each side of the fuse and wrap it in tape and keep it where it is accessible but right at the battery positive terminal, in front of the charger lead.
fuse holders melt because the contacts where the fuse clip is crimped onto the wire is usually just totally inadequate to handle the current so the fuse holder melts from the heat even before the fuse blows.
i liked the idea that bob had of just soldering the main wire onto the fuse legs. use a big fuse to start with so it takes something like a real short to blow it. say 70A, then after you solder the legs to the wire, use some of the insulating sheet stuff used in the batteries to separate them from the case, put that on each side of the fuse and wrap it in tape and keep it where it is accessible but right at the battery positive terminal, in front of the charger lead.
dogman dan
1 PW
True enough a fuse holder melting is not an overcurrent problem but a high resistance contact issue.
jateureka
10 kW
Did you manage to replace your fuse assembly, as discussed here? http://endless-sphere.com/forums/viewtopic.php?f=14&t=42747
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