'Pop' goes the HV fuse!

I knew I was asking for it.

I have a rather 'close shave' HV fuse - a 200A semiconductor Bussman - in the lithium battery pack. It's rated for 200A continuous, but can tolerate more for finite periods of time, depending on the time duration. This is what is referred to as the I-T curve. For example, the fuse will open at 400A for 10 sec, 600A for 6 sec... you get the picture.

I have been driving Electro with my battery pack for a month. 'Why did the fuse blow today?' you might ask. Well, follow along on the path with me! Each step added more instantaneous torque, which added instantaneous current draw.

1) Install the battery pack, with a nomimal HV fuse, and drive rather conservatively in city driving.
2) Install the new transmission - all of a sudden, starting in 1st gear is really fun!
3) I drive less conservatively on hills after installing my e-meter and seeing that hills don't take that much energy to drive up.
4) Sound-proof for freeway driving. Freeway driving is a lot of fun now! Especially at higher speeds.
5) Install cool-looking (but less efficient and heavier) wheels on Electro. Suddenly first gear starting from a stop requires more torque/current than before.

All these factors combined to hit my fuse today. Starting my drive home from work, I entered the *freeway* on-ramp from a metering light, *rapidly accelerating to freeway speed*, *on an on-ramp that is up a hill*, and *with heavier wheels*. POP! I got a tow truck ride home.

I will be searching for a more lenient fuse (300A perhaps) that can tolerate my driving style. In the meantime, I have reinstalled a safety fuse (500A semiconductor) in the slot, so that in the event of a calamity/short circuit it will still protect me but may not protect the pack.

Live and learn!