36v10ah Nimh Pack from Batteryspace.com Issue

[joystix2]

I have one of those 36v10ah Nimh from batteryspace.com and it has never ran with my bd36v system. It would always cut in and out. I figured the voltage was sagging really bad so I opened it up and changed the tiny 18g wires to 14g wires. Its still not working. My brother and I ran a Voltage meter on it while throttleing up and riding and sure enough it's dropping from 36v, 32v, 30v then straight to 9-10v then it shuts off. An so on... I took a picture of the the way they have it set up and found a heat sensor (I think its the white thing in the pic which is hooked up between the charging wires to the negative. I do not know what the orangeish/tan thing is on the left. I think it may be a cap but not sure. I was thinking since the warranty is shot just by opening it up that maybe I should just bypass and remove the orange square thing. Could this be the cause of my problem with the huge voltage sag? Any thoughts would be greatly appreciated...

Thanks
Ric

 

[Link]

Hmm, interesting. A cap would potentially smooth voltage spikes, but that one is no where near big enough to do that. Weird...I'd cut it off if it doesn't seem to serve any particularly useful service, which it doesn't.

 

[Anonymous]

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[Toorbough ULL-Zeveigh]

Retriggerable fuse, if it was a normal fuse it would be blown right now.
You have a short somewhere or the motor is simply too much draw for the pack & the polyswitch is protecting the pack.
http://en.wikipedia.org/wiki/Polyswitch

 

[Link]

Retriggerable fuse, if it was a normal fuse it would be blown right now.
You have a short somewhere.

I dunno. If it was a fuse, why would the voltage be ramping down like that? Though I guess if it took a while to open that would sort of make sense.

If it is a fuse, perhaps the motor is just drawing enough current to make it trip.

 

[Ypedal]

That yellow thing on the left i think might be a thermistor ( tells the charger it's ok to charge unless the pack is too hot )

The white thing, i beleive is inline with the " discharge " wires.. so if the pack overheats it opens.. ? Then you get a fuse between the pack and the controller for over-current or a short.

damn. who says ebiking is not a safe sport..

 

[Anonymous]

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[docnjoj]

Im still using my BS 10 ah pack but I had to add 5 cells in series to make up for sag! It still doesnt come close to a 36 volt ping for power! I use an Astro 112D and it charges up to 44volts at 30 cells and 50 volts at 35 cells. I removed my thermal switch as it is used for charging cut off with their silly little 12 volt chargers. Cant wait till Lifepo4 shows up for my bike.
otherdoc

 

[joystix2]

Well after all the replies and IM'ing Fechter I decided to just bypass them and take them off. Now the battery works fine without shutting down. Thanks for everyones help and fast response What a great site......

Ric

 

[monster]

it could be that yours had a bad fuse or thermal fuse or a lose connection that was causing resistance. this is unusual.

I removed my thermal switch as it is used for charging cut off with their silly little 12 volt chargers. Cant wait till Lifepo4 shows up for my bike.
otherdoc

docnjoj dont charge nimh without a temperature cut-off switch to terminate the charge or you will cook your batteries. don't think that Lifepo4 will solve reliability problems because it has a BMS which is 10x more electronics and therefore 10x more things to go wrong! nimh is usually very reliable, ive only had one cell go bad on me out of the 130cells and 2 years that i've used them.

 

[docnjoj]

Thanks Monster! The Astro charger doesnt use Delta T at all! It seems to work well, as I have not had a problem in 6+ years of its use, on both Nicads and Nimh! They really have the Delta V situation well in hand. It can and will charge 40 cells in series ( or fewer, of course)
otherDoc