1920 Detroit Electric Car Battery fuse question

[dithomas]

I am working on restoring a 1920 Detroit Electric Car. There were no fuses in the battery circuits and I want to install fuses.

The car has two battery packs, one in the front and one on the back, each battery pack is 42 volts DC with 240 amp/hour capacity.

From what I have been able to find out, the max amp draw may be 60 amps at starting when the front and back batteries are connected in parallel. I assume that once the car starts rolling the amps will drop.

I do not think I need to be concerned with time over current as much as having an instantaneous clearing of a short circuit.

Any thoughts and ideas would be appropriated since I am not familiar with the level of fault currents that can be produced by batteries.

 

[MikeHalloran]

So, install a couple of fuses.
Carry a couple of bigger fuses.


Mike Halloran
Pembroke Pines, FL, USA

 

[ScottyUK]

Any DC-qualified HRC fuse will be ok for an automotive battery. Even the really big flooded cells struggle to get above 10kA of fault level, which is within the range of almost all DC fuselinks. Don't fuse the connection to the chassis.

 

[itsmoked]

People regularly fuse between batteries somewhere as it helps when a wrench gets dropped across cells. If you only had an
'output' fuse you'd still be screwed.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[dithomas]

ScottyUK,

Thanks for the reply. The DC system is not grounded. I think I need to fuse the + and -.

I will investigate the HRC fuse.