MG Midget + Geo Metro 3cyl = MGeo

[guudasitgets]

Originally Posted by UFO

If you have a cell go bad, with no balancing scheme, the alternator will overcharge a stack, and then you will have a fire on your hands.

I'm in the battery biz, you are correct, they can pop a pretty big BANG!

[nimblemotors]

Originally Posted by Varn

Tiny battery
It looks like the leads are pretty small (12g) for the impact of the starter draw.
Where did you get the cells?
Thanks

I bought them from some chinese r/c parts seller I think, they are the cells used in dewalt 36v power tools. You can find them on ebay pretty easily.
The wires can be small because they are very short.

[nimblemotors]

Originally Posted by UFO

If you have a cell go bad, with no balancing scheme, the alternator will overcharge a stack, and then you will have a fire on your hands.

I don't think this is much of an issue, there are 4 serial, 3 cells in parallel, all three must go to zero volts so the rest must take up the 14.5 volts. That is really just 5 volts per cell each, don't think that will cause them to blow up.
It isn't like NiMH or NiCad that will explode if overcharged, LiFePo will not keep taking in a charge when full.

[Varn]

Hi thanks for the info on sourcing the batteries.

If it is 12 ga wire a foot long it is going to have to drop about a third of a volt and adsorb about 65 watts at 200 amps. It could very well turn into a soldering gun.

It has been years since I was a electronics tech but still remember ohms law

[nimblemotors]

I haven't done the calcs but it isn't 12inches of wire, the distance between cells and to the 1/4 ss bolt is maybe one inch, and the starter draws less than 100amps. no problem.

Originally Posted by Varn

Hi thanks for the info on sourcing the batteries.

If it is 12 ga wire a foot long it is going to have to drop about a third of a volt and adsorb about 65 watts at 200 amps. It could very well turn into a soldering gun.

It has been years since I was a electronics tech but still remember ohms law

[Daox]

65W for 2 seconds is nothing. If he cranks the engine over for 30 seconds straight it'll start getting warm though.

[nimblemotors]

Finished the dashboard, at least mostly. The firmware for doing the mpg seems to have a problem, when accelerating the injector pulses spike orders of magnitude larger. I had a problem with the brakes, they wouldn't bleed.
Turns out I needed to level the MC, and bubbles came out, fixed, then the rear caliper needed to be rotated to get the air up to the bleeder, so I took it off bled it and put it back on. Now all works great.

I took it for a ride around the block, and got it into second gear.
Two things were apparant, the tall rear tires indeed give it long gearing,
I could go quite fast in 1st gear, and second, the car has LOTS of power!

I need to get his car finished for the Sept 15-16 Green Car Expo in sfbay. Is anyone planning to attend this show??

Here is the dash on the car. I embedded tweeters into the dash.
I've sinced changed the LCD to one with a backlight, it was pitch black in the dark, so now it has a white background when turned on.

[some_other_dave]

I hadn't been planning on going to the Expo, but now I'm thinking it might be worthwhile to see the MGeo!

-soD

[Frankencar]

Originally Posted by nimblemotors

I need to get his car finished for the Sept 15-16 Green Car Expo in sfbay. Is anyone planning to attend this show??

Might need to go if you are bringing that. Been following your thread for a while & I love that build! I have always wanted to build a Midget - ever since the first time I rode in my Dad's 73' MG. Are you bringing it for sure?

[guudasitgets]

I like the no key power up, with how easy it is to rip off a car nowadays wonder if I could just hide a toggleswitch and a starter button and be done with it.