What kind of fuse would I use with a 48v 20ah LiFePO4 batt

[mythprod]

Hi guys, I blew my battery fuse this morning. The old fuse had F4UAL250V on it and I can see it's a 250V, I'm wondering what kind of fuse I should get to replace this on my battery's positive / red cable.

My battery is a 48v 20ah LiFePO4 battery. My motor is 1000W front wheel hub motor.

The fuse specs aren't documented on the webpage of the battery that I can see and no response from vendor yet, is there any way to tell what kind of fuse I should get for my battery?

TIA!

 

[mythprod]

Altered original message to be more clear.

 

[skeetab5780]

it sorta depends on how much your controller draws. you can probably only pull 30-40 amps from that pack before you starts to overdue it anyway. So if your controller is stock you can use an inline 30A fuseholder..(similar to old car fuses) but if you have a larger amp controller you may want something bigger like a 40 or 50amp Car stereo inline fuse.

http://www.google.com/products/catalog?q=30amp+inline+fuse+holder&hl=en&prmd=imvns&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.&biw=1600&bih=809&um=1&ie=UTF-8&cid=10550804676831676171&sa=X&ei=7aBrUKHUDMyB0QGVloCgDQ&ved=0CGwQ8wIwBA

http://www.ebay.com/itm/230856894413?hlp=false

 

[mythprod]

Thank you, that was starting to drive me nuts, I hate when stuff isn't marked!

I pinned these down on Amazon, they're 250v & 30a so I think that's what I need. However, all I could find in a brick-and-mortar (home depot) were 30a 32v fuses. Do you think I could use the 32v fuses for a few days until the Amazon fuses come in or should I even try? It's nice all week and I will be missing out on some great weather! The discrepency between 250v and 32v is obviously big and am not familiar enough with this stuff to know if it's no big deal or something I shouldn't even try?

 

[skeetab5780]

usually if your under the voltage range with your operating voltage you should be fine.. but with fuses im not sure if it matters as much. its more about the Ampacity. a 12awg wire is usually rated up to 600volts but rarely do you see it happen. i doubt youll have a problem with the 32v 30amp fuses but using the 250v ones will be fine too

 

[DAND214]

You've got to be kidding! No auto part shops in your neck of the world? I guess some where in the states, but not listed.

It's just a fuse, 30 or 40 amp auto fuse. Nothind special for an E-bike.

Dan

 

[mythprod]

You've got to be kidding! No auto part shops in your neck of the world? I guess some where in the states, but not listed.

It's just a fuse, 30 or 40 amp auto fuse. Nothind special for an E-bike.

Dan

I'm just using a glass cartridge fuse that snaps into the inline connector that came with the battery. I'm very new to all of this so maybe they are in the shops right under my nose. I know I can put a new inline connector in that takes the car fuse kind but I was attempting to simply replace with the same type / kind (glass cartridge) that came with the battery.

 

[DAND214]

They still sell the glas fuses almost everywhere.
I know we went to the blade type years go, there are plenty of cars with the old glas fuses around.
Take it in and ask if they have some a 30 or 40 should be fine.
goog luck with your search
.

Dan

 

[mythprod]

The volts was what I was most worried about (which having read this thread doesn't sound like much of an issue, especially for a fuse?). I couldn't find any 250v 30a+ glass cartridge fuses locally but haven't checked that many places yet. I can buy online, I was more wanting to use the fuses I purchased last night that were 32v vs. 250v. I'll give them a try today and see how it goes

 

[arkmundi]

Using a Watts Up meter, you could determine the maximum draw in amps. Add in about 10% because you don't want to unnecessarily blow it. Then get an off the shelf fuse rated for that.

 

[mythprod]

That's a good idea, I'll look into it. In the meantime I made it to work alright with the 32v 30a fuse. I'm really glad because it's supposed to turn much colder from here on out.

 

[dnmun]

you don't wanna use glass cartridge fuses because the contact area is so small. even with the spade type auto fuses they overheat because the contact is so small. you should just solder a maxi 40A fuse into the power lead at the battery.

 

[Punx0r]

The contact area on a glass cartridge fuse is very large. Not high pressure, but large.

A fuse for automotive use will work fine for you at 48V. If your BMS uses one of these fuses then a direct replacement would be the easiest solution, although find out why the last one blew.

 

[dnmun]

the inline fuse holders just contact a little bit on each end. i don't think he is using the board mount clips.

 

[Punx0r]

Ah, I see. I was thinking it was actually on the BMS board...

Slightly OT, but regarding mini-blade fuses, I've experienced some holders (or cheap fuses) melting at only 10A. Yet car wiring use them up to 30A without issue for decades. The key to success with them may be in using quality quality components.