36-100V 30-45A fuse and fuse holder?

[cwah]

Hello there,

I don't know where to look to find a fuse and fuse holder able to support from 36V to 100V?

Most of them are limited to 12 or 24V, so can't use them on my ebike.

Any idea where I could find them?

 

[bionx 1954]

I have been using a 10 guage in line fuse holder with a 40A blade fuse, they are in most auto stores

 

[Kin]

36v is very doable. 100v you have more concern about arcing. You might want to check out the search engine, I know I saw LFP make a thread about high amp high voltage DC fuses a while ago. There was a lot of conversation there. Many people here run fuses above there spec range (higher voltage than rated). Usually, that won't be a problem, but in the worst case you could sustain current through arcing.

 

[dnmun]

if you use a BMS you can skip the fuse, since the BMS will shut off when the current surges. if you use SLA, you need a fuse for protection. bob would just solder the wire to each leg of the auto fuses. that is the best way to get a low resistance connection across the fuse.

 

[llile]

if you use a BMS you can skip the fuse, since the BMS will shut off when the current surges. if you use SLA, you need a fuse for protection. bob would just solder the wire to each leg of the auto fuses. that is the best way to get a low resistance connection across the fuse.

I consider it bad advice to skip the fuse. Here is a case in point where the BMS does not protect things: in messing around with some wires, Being VERY careful not to touch them, I ended up touching the two battery wires. KAPOW!. Very shortly afterward I had a bad failure of one of the BMS FETS, and after that shorted out it wiped out my charger as well.

Having learned that lesson, I was VERY careful with my next battery... and did the same accident again. I have never claimed to be very smart. The first thing you should do with any battery that doesn't already have Anderson terminals on the end is to install a fuseholder and fuse. The fuse is also a disconnect, rendering the rest of the power wiring electrically safe. The BMS DOES NOT protect against this kind of accident. It DOES NOT protect against a pinched plus and minus wire shorting out and making sparks. It doesn't protect things when your motor controller shorts out.

For 36V you can just buy automotive fuses. Mouser Electronics has 80V fuses that look like the big brother to automotive fuses; http://www.mouser.com/ProductDetail/Littelfuse/16668855501/?qs=W9dJx%252bPHassNuCclZozKT6PZ%2f2%252b3zfjceLI4D7IzZBQ%3d

Here is another fuse actually made for electric vehicles:
http://www.mouser.com/ProductDetail/Littelfuse/15757015501/?qs=6SB1pk40t9YJh1%252b0RzodZCATZ1k0XWFx9O%252bfnH5j0BM%3d

 

[cwah]

Thanks guys.

Found an ebay seller telling me this fuse can handle from 3V to 250V:
http://www.ebay.co.uk/itm/ws/eBayISAPI.dll?ViewItem&item=390339370780&ssPageName=ADME:X:eRTM:GB:1123#ht_3001wt_1163

Maybe I can try this one.

 

[corkscrew]

Go to your local auto parts store and look for a maxi fuse and holder. I'm using a 60amp fuse on my 48v trike with no issues.

 

[Kin]

Yeah, that ebay seller is selling you a regular ATO fuse. It's absolutely not rated for 250v, but MAYBE it's ok with it. I should say, though, that the maxi blade fuse looks better because the s shaped curve has a bigger gap than the ATO fuse you linked.

Regardless, these things might not matter much. It's certainly still better than no fuse.

 

[sn0wchyld]

im guesing the seller meant they can handle 250v isolation, because yea, they're just normal auto fuses.

i'm using the basic auto ones at 100v, though I haven't tested if theyll ark at all. With lipo its not such a big deal anyway the 4mm bullets make great fuses!! :wink:

but really, fuses are a good idea.

 

[alsmith]

I wouldn't trust that seller- 16AWG wire fitted to the fuse is only rated at 22 Amps so using a 40 Amp fuse with it could lead to some rather serious problems. For 40A you need at least 12AWG (2mm) cable.

 

[Joe Perez]

I consider it bad advice to skip the fuse. Here is a case in point where the BMS does not protect things: in messing around with some wires, Being VERY careful not to touch them, I ended up touching the two battery wires. KAPOW!. Very shortly afterward I had a bad failure of one of the BMS FETS, and after that shorted out it wiped out my charger as well.

While I wholeheartedly agree that a fuse should be installed in the system, you should not count on it to protect the FETs in your BMS. Neither fuses nor circuit breakers operate instantaneously- they inherently take some time to operate in an overload condition. For a very high-quality and tightly-specified magnetic breaker, this time can be as low as a few hundred milliseconds, and while this is sufficient to protect wires from melting and causing a fire, it's an eternity to a semiconductor.

So definitely fuse the system, but don't let the fuse lull you into a false sense of security. Shorting the output of a BMS is going to destroy some components, regardless of whether a fuse is installed or not.


cwah, if you can't find a suitable fuseholder locally, Maplin has a couple that would work for you:

http://www.maplin.co.uk/water-resistant-maxi-fuse-holder-30444
http://www.maplin.co.uk/water-resistant-fuse-holder-30428

 

[cwah]

Thanks for the advice.

Actually I have my Lyen controller that has his FETs that melted.. just by applying gently the throttle.

What's the best way to protect the FETs?