Inline fuse questions

[EMagnaE]

I have a 1000 watt 48 volt ebike kit. Its a cheap ebay kit. It has a 36/48 volt controller. I am currently running a 36 volt 20 ah battery because I have that battery from a different bike and have yet to get a 48 volt battery. I have put about 600 miles on it. I have noticed it has no inline fuses. I want to put 1 between the battery and the controller. I was thinking of getting an automotive blade type fuse 30 amp and put it between the battery and the controller. Does this sound right? Any ideas or advice?
Thx

 

[indianajo]

I have done that. I used AG3 fuses which are a bit more expensive. More distance between the terminals in the rain.
I have never blown one. You surely do not want to blow the fuse inside a battery.
Those main capacitors in generic controllers, I have never owned one that didn't leak down in < 20 seconds new. The controllers spark when you leave them disconnected then re-plug the connector. I've replaced those caps with industrial long life caps (<3000 hours service life) from nichicon, panasonic, or rubicon, and the time between sparks when re-plugging the battery connector increases to several minutes.

 

[EMagnaE]

What size fuse do you think I should use? Continuous discharge is 20 amp Peak discharge is 60 amp.
Thx

 

[indianajo]

If you can get a 50 amp AG3 go for that. https://www.digikey.com/en/products/detail/schurter-inc/SUT-H-6332-50A00-CTG-TT-NI/9760594 60 amp CCR fuses fit in open clips, which are not sealed against rain. There is a 3 bin swing out holder for Zrail, but that is too big to mount on a bike IMHO. The 3 bin holders are for 480 v 3 phase motor supply.

 

[Gionnirocket]

I've been using these FKS ATO for between the battery and controller (20a) and a 4a for a tap to lights/horn on a 48v 750w mid drive. You might want to go with the Maxi Blade as it offers a higher range of fuses. I would do as you initially thought and go with the 30a for the best protection and move to 35 - 40a if you get nuisance trips. The FKS have been handling spikes well and I haven't blown one in 10k mi. The Maxi add the time delay feature just for spikes.