Got a fuse question on my electric bicycle

[ElectricBikeXP]

Hi everyone and thanks for having me .one of my 2 ebikes is a 2011 mongoose electric bicycle.it has a currie motor.in my battery pack I have a 40 amp glass fuse and sometimes when turn the twist throttle it blows the fuse.this bicycle does not have a pedal assist .if I want to pedal using the motor I have to hold the throttle and yes I can use it without the throttle as well.i have replaced the motor and the throttle .question is could it be I may need a new controller? I have blown 3 fuses already and the batteries are a year old.thanks for everyone's help in advance.. the bike and battery pics are on the bottom

Mark

 

[PedalUma]

I am jumping in. Does this bike have gears? Would you please send a photo from the other side?
The EBR team will help. Likely you need a new chain and we will discus riding technique. The fuse is there as a failsafe to save your controller and the motor.

 

[ElectricBikeXP]

It does have gears in the back it's a 7 speed. I forgot to mention this is a factory built bike it was given to me and I like the bike and like to ride it along with my lectric xp .I got other pics

 

[PedalUma]

Okay!
Thank you for the photos. That helps a lot.
This is my recommendation. And if you want to know who is saying this with reviews go to Google Maps, zero in Petaluma CA, and look for eBike repair.
1) Replace the main chain with a KMC X-8. Clean the shipping lube off of the new chain with MuckOff Dry with the bike upside-down.
2) Replace the motor chain. It has been stressed.
3) Launch from a start by pedaling in the lowest gear, then feather in the throttle for assistance so you do not overload the fuse.
4) Watch YouTube on chain replacement.
5) Check the bottom bracket by moving it left and right with the chain off the chainring. This one is not sealed. If there is any play or it does not spin freely, replace it with a 68x118 sealed cartridge bottom bracket. Confirm the 118mm with a caliper first. Your current bottom bracket lasts only six-months. The sealed one will last for years.

 

[ElectricBikeXP]

Thanks for all your help I will try that. I have noticed both chains getting worn . But I will watch a video and change them both.you have been a great help and thankyou very much.i love my lectric xp electric bike don't get me wrong but I also love this old mongoose electric bike also lol

 

[Gionnirocket]

What type of glass fuse are you using as a replacement?
What is the voltage rating?
Is it rated for DC current?

 

[ElectricBikeXP]

What type of glass fuse are you using as a replacement?
What is the voltage rating?
Is it rated for DC current?

40 amp.thats what it calls for. I got it through electric scooter parts.com I looked my.model up and it showed what I needed.

 

[Gionnirocket]

I may be incorrect... But I do not know of any DC rated glass fuses at 40 amp.
If you look closely at the fuse you should see it's rating scribed on the metal ends. Post a pic maybe?

Correction.... I did a quick search and did find one... Though it doesn't state DC, it does state for use with 32v battery systems. 40a
So next I would check to see if it is " fast acting" or "slow blow".
Slow blow is typically best with motor loads

 

[ElectricBikeXP]

That's what I bought off electric scooter parts

 

[Gionnirocket]

Thanks... From a quick search all that I could find using AGC 40 is a 32v/40a/fast acting fuse. If your original fuse was the slow blow type which do wear out over time... That could be part or all of the problem.
What is the voltage of your battery?

 

[ElectricBikeXP]

12 volt....the bike is a CB 12 volt 450 that's what it says on the frame anyway lol.

 

[ElectricBikeXP]

It takes 2 12 volt batteries in the case

 

[Gionnirocket]

Is this 40 amp what you purchased?

They don't specify DC, but do specify 125v / 250v... These are AC ratings which are not necessarily transferable to DC which requires a larger gap when blown.
That said at 24v you're probably ok.
Is the fuse holder easily replaced?
If so I would replace it with a more common Automotive style fuse holder in which finding the proper fuse will be easier.
40a ATO Fuse

edit: If 450 in your description is motor wattage... You may be able to use a smaller 30a fuse.

 

[ElectricBikeXP]

The fuse holder in in the wiring harness and they are out of stock.i figured this being a 10 year old bike parts might be hard to come by

 

[ElectricBikeXP]

Yes that's the fuse I purchased

 

[Gionnirocket]

How handy are you electrically?
If you can snip the old fuse holder out of the harness... You may be able to butt splice a new one in.
Take a pic of the holder and harness

 

[ElectricBikeXP]

I am not that good with electricity lol I will have to go tear the box apart and send it to u when I get home and again thanks everyone who has helped so far.i couldn't have got this far with out you people

 

[Gionnirocket]

I am not that good with electricity lol I will have to go tear the box apart and send it to u when I get home and again thanks everyone who has helped so far.i couldn't have got this far with out you people

No worries...
Understand that to a certain extent I'm taking an educated guess here.
If it was my situation I would put a watt meter on the set up and see what the no load current is and under what conditions the fuse blows.
Though the fuse that you are using " may be ok" it's really not the right fuse or rated for a 24V DC motor load.

 

[ElectricBikeXP]

Ok I got the battery box apart.in the one pic do I have the wires hooked up correctly?

 

[Gionnirocket]

Ok I got the battery box apart.in the one pic do I have the wires hooked up correctly?

Looks good to me.
If you'd like to put a properly rated fuse... I can walk you through it. Not hard at all... It'll look pretty much as you have it now