V8 died, suspecting blown fuse

[Heymelon]

Hi there! So the wheel just died during what I now know was too heavy uphill offroad riding at my near 220 pounds. I didn't think or feel I was pushing it that hard, but then I hit some deep mud and I think the sudden acceleration attempt was just asking too much. I guess. 

It won't power on, not responding to power button. It seems to take charge and the charger indicator turns red, but the wheel dosen't power on like usual with charger connected. 

The wheel/tire is as easy to free spin and move as always. So. Do you think this is a blown fuse? Can I just buy any 30A pin fuse that fits and install it, or should I do something else? 

Also I saw that there exists smart fuses which can be re-enabled if overloaded. Can/Should I get one of those? 

 

https://www.ddesign.nu/product/sakring-aterstallningsbar-30a-gron-qsp-products?referer=google-shopping&country=SE&gclid=Cj0KCQjw1N2TBhCOARIsAGVHQc76N96iBzftMcsJnqAbBmP8nVqHo8jfMmIr8RbOHwVBmyt17RDKE-EaAqjuEALw_wcB

[Heymelon]

Oh. It was soldered... 

[goatman]

id snip it in half and try to unsolder each blade separately

[Chriull]

2 hours ago, Heymelon said:

Oh. It was soldered... 

And is (was) it still ok or blown?

Anything else looking suspicious? Capacitor legs intact? Wires, pcb tracks, solder joints?

5 hours ago, Heymelon said:

Also I saw that there exists smart fuses which can be re-enabled if overloaded. Can/Should I get one of those? 

As these are car fuses most probably not. Do they work with 84V?

Do they withstand higher short time current spikes so you won't faceplant? With about similar characteristics as the used fuses?

[LightWave]

5 hours ago, Heymelon said:

Also I saw that there exists smart fuses which can be re-enabled if overloaded. Can/Should I get one of those? 

 

https://www.ddesign.nu/product/sakring-aterstallningsbar-30a-gron-qsp-products?referer=google-shopping&country=SE&gclid=Cj0KCQjw1N2TBhCOARIsAGVHQc76N96iBzftMcsJnqAbBmP8nVqHo8jfMmIr8RbOHwVBmyt17RDKE-EaAqjuEALw_wcB

I don't see why not and I would be interested to hear how that works out if you try it!

5 hours ago, Heymelon said:

Do you think this is a blown fuse?

Yes it's a common issue

[Heymelon]

3 hours ago, goatman said:

id snip it in half and try to unsolder each blade separately

Ty that's basically what I ended up doing. It had a lot of tin and glue on the backside. Maybe for some short circuit protection reasons. 

1 hour ago, Chriull said:

And is (was) it still ok or blown?

Anything else looking suspicious? Capacitor legs intact? Wires, pcb tracks, solder joints?

As these are car fuses most probably not. Do they work with 84V?

Do they withstand higher short time current spikes so you won't faceplant? With about similar characteristics as the used fuses?

It was blown! Nothing else looked suspicious, but it's not that easy to see everything but there were no signs. I mean to my understanding all you need is a fuse that fits with the correct amperage. 

1 hour ago, ElectronxCycles said:

I don't see why not and I would be interested to hear how that works out if you try it!

Yes it's a common issue

I'll update once the wheel get's a new fuse but I can now confirm that this was the issue, and it was blown. I've gotten it to work with a cable acting as temp fuse. So I'll have to be careful until I get a new proper one. My neighbor surprisingly and amazingly had all the tools and knowhow, and helped me out with it. 

[Chriull]

5 hours ago, Heymelon said:

I mean to my understanding all you need is a fuse that fits with the correct amperage. 

No. Fuses with the same amperage can have many different characteristics like mainly from (very) slow to fast. Or suited to protect motors, etc..

Electric fuses should be also (more) sensitive to overvoltage.

Edited May 8, 2022 by Chriull

[Heymelon]

On 5/9/2022 at 1:37 AM, Chriull said:

No. Fuses with the same amperage can have many different characteristics like mainly from (very) slow to fast. Or suited to protect motors, etc..

Electric fuses should be also (more) sensitive to overvoltage.

Right, that was a bad statement by me. But in terms of available and common fuses used in cars and what not, they seem to all be 32v and "fast acting". Not much wiggle room there in terms of getting one of those at 30A that fits in the wheels board it seems. Some people are suggesting that will be a problem (because of the lover V rating), others are saying that it shouldn't matter. 

[Chriull]

49 minutes ago, Heymelon said:

Some people are suggesting that will be a problem (because of the lover V rating), others are saying that it shouldn't matter. 

"Normal" fuses with some 32V rating will still work (somehow) to disconnect ~100V. Takes just a bit longer until the electric arc eroded enough material.

My coment above was in regard of the electronic, resettable fuse you mentioned- if they are specified for 32V chance could be high that they will in no way work for higher voltages.

[OneLeg]

I think primarily you must have blown the Mosfets which then may have blown the fuse.

[Heymelon]

On 5/16/2022 at 7:40 PM, OneLeg said:

I think primarily you must have blown the Mosfets which then may have blown the fuse.

It was just the fuse. The wheel worked again after I fixed it. 

[OneLeg]

On 5/19/2022 at 3:29 AM, Heymelon said:

It was just the fuse. The wheel worked again after I fixed it. 

oh much easier to fix. congrats.

I was given a V8 that had been abused, had a broken motor. With 1000km of abuse the battery pack left much worse than one with 4000km... With 2800km i am having to rebuild it.

If you have blown a fuse I suspect that you have hammered those 10A batteries... don't be surprirse if in 1000km your pedals start dipping, and you hear the alarm for low voltage when you accelerate.