My Wheelchair has 58v Fuses on a 24v set up, Why?

First, I'm not even sure that's a fuse!
It could be a relay or a semiconductor device or a trip.
Anyhow the voltage is probably a maximum rating not the limit/trip level.
Most fuses don't giveadamn about the voltage upto the point where there are size limitations (e.g a tiny printed fuse for low voltage use on a circuit board wouldn't be any good at 240v AC as it could arc over, due to lack of clearance distance)
So a fuse will have it's current capacity and a max working voltage.

Be aware that fuses are VERY imprecise. A 2 amp fuse may not blow until 3 amps (always test 'em first.. sorry that's just a very old electrical joke)
Hope that clears it up.

Also if you are new to this game, be very wary of the high currents and nasty torques you can get from equipment like that, just doing my electric golf trolley, I had the darned thing run away a few times and that's much less power than you are playing with.

Also beware of limiting air flow/ventilation round batteries or electronics for reasons of heat generation and gassing.

Del

How are the power leads connected to it?
To be honest it doesn't look like a fuse to me either.

Del makes a very valid point about alterations to the battery bow because of the problem of battery gasses.

Sorry Del but I've got silly images in my mind of you sprinting after the golf cart.

Sorry Del but I've got silly images in my mind of you sprinting after the golf cart.
They are probably pretty accurate.
One day on the course it was raining, the water got into the electronics and the trolley ended up wandering off on it's own and ended in up in a brook.
Del

HaHa………………. Splutter, cough………
Tony's lay in a heap laughing.

Have you seen the TV series "The Detectives"?

My apologies to the OP I know this isn't helping!

Hey again,

Thanks every one for your thoughts thus far.

here is a link that, I think, confirms it is in fact a fuse...

http://www.littelfuse.com/data/en/Data_Sheets/Littelfuse-Automotive-Bolt-down-Fuse-CF-58V.pdf

I gather by posts so far that overkill with fuses is important due to unreliability.

Also that good ventilation is important, which I guessed it might be, but is there likely to be much gas emission from fully sealed gel battery's?

As to the way of connection, as can be seen in the image provided, the bolt running through this thing bolts directly to the battery terminal & then a cable connects to the opposite side of the thing by a common ring terminal by what is called an "isolation nut", that's the red plastic nut looking doodad. The cable then runs off to the business go stuff (forgiveness for armature lingo jargon).

Thanks again for all help as I can do without drifting off into nearby creeks, oncoming traffic or in fact having my arse catch fire as I suggested.

I see, nice link.
but is there likely to be much gas emission from fully sealed gel battery's?
I'm sorry, but your time is up, for further answers please insert a £1 coin.
Nah, you're prob' right, gel battery shouldn't outgas, but a manufacture's website will provide better info than a virtual cat.
The nomex underwear may be a good investment just in case.
Del

Hey guys that is a fuse. The fuse is the little square block. He has it taken as an assembly with the terminal installed.

The 58V is the max voltage the fuse is design for not what voltage the can be only used for. If there are fuses on each battery they are to limit short circuit of the battery. Which if shorted the battery will off gas excessively. This excessive gas can be an explosive hazard. Its not like someone that would be using this type of equipment going to get off it very quickly.

<...the manufactures just gone complete overkill so as to not set my arse on fire ...>

Well, if it's safe to break on 58V then it will be safe to break on 24V as well. Don't bu&&er about with it, then, for risk of rectal conflagration, invalidating what might be left of the manufacturer's warranty, and becoming very unpopular with the local fire and ambulance authorities and the home insurance provider.

It should be noted, because you mentioned wanting to redesign the circuit to use a physically smaller fuse, that there is a lot more to fuse selection than just the physical size, maximum voltage rating or even the amp rating. There is a curve involved, usually an i²t curve to be precise, that takes into consideration the expected peak currents that the circuit will see, the duration of those peaks and the let-through current that any down stream components can withstand. Someone most likely spent a good amount of time engineering and testing the components in that wheelchair system before selecting that fuse to properly protect them and not constantly blow. Redesigning it without that thought process is asking for all kinds of trouble, including the risk of fire or of making someone so frustrated at constantly blowing the new fuse that they bypass it inappropriately and start cooking buns.

Hey every one & thanks again... Again!

All points have been taken into consideration. So I will endeavour to use fuses of the same or at least equal capacity, It will be a bit of a tight fit but its still doable without any major redesigning of the circuit. I will be doing testing too once adjustments have been made to be safe.

With a bit of help I'll pimp my ride out yet & Keep by buns in the spectacular condition they are at present!

Nice work Del on the pimped golf caddy.

Many thanks!

read below its from google ,i hope voltage rating of fuse more is better ,at least voltage rating of fuse should be 1.5 times of supply voltage,otherwise it can be melt like metal and exist permanent continuity between sourse to load.

see below ,sorry for copy paste

Rated voltage

Voltage rating of the fuse must be greater than or equal to what would become the open circuit voltage. For example, a glass tube fuse rated at 32 volts would not reliably interrupt current from a voltage source of 120 or 230 V. If a 32 V fuse attempts to interrupt the 120 or 230 V source, an arc may result. Plasma inside that glass tube fuse may continue to conduct current until current eventually so diminishes that plasma reverts to an insulating gas. Rated voltage should be larger than the maximum voltage source it would have to disconnect. This requirement applies to every type of fuse.

Rated voltage remains same for any one fuse, even when similar fuses are connected in series. Connecting fuses in series does not increase the rated voltage.

Medium-voltage fuses rated for a few thousand volts are never used on low voltage circuits, because of their cost and because they cannot properly clear the circuit when operating at very low voltages