Project: The Electric Booger (budget EV conversion - '92 Mazda MX-3)

[allen_dodge]

hello! first of all, this whole time I thought marine batteries WERE deep cycle batteries, but I guess that shows how much I know.

Secondly, I know this probably defeats the entire purpose, but have you considered the inclusion of a small diesel generator, like the homemade electric car they built on Top Gear? Their solution was... flawed, at best, but I think it has real potential if executed properly. That would mean a need for less batteries, reducing weight. It should theoretically extend the life of the batteries as well by keeping the voltage from dropping too much. However, diesel generators are not exactly cheap even for a used one but it may or may not prove to be a cost effective alternative to buying a whole slew of brand new, high quality cells. Anyhoo, just a thought, hope it helps

[bennelson]

Project is looking good!

Great Job!

-Ben

[allen_dodge]

Sorry to double post, but that would give you a source of heat as well. Volkswagen is in the process of putting one of their concept cars into production as we speak, it's a 2 seater diesel-electric hybrid that gives about 200-300+ mpg! (no, that's not a typo) As long as you're wall charging, you are still running on fossil fuels anyways, so unless you go full solar or other alternative energy, it's simply out of sight, out of mind. The obvious downside is that typical diesel clatter inside an otherwise quiet car, but a sound insulated box would certainly help some. Also, it would surely be possible to run the generator on veggie oil... just trying to think outside the box

[dtbaker61]

having an on-board generator is dangerous, noisy, ineffective, and expensive.

If its tiny, it cannot possibly generate juice as fast as you are using it. running an ICE generator on board, solving the fuel safety, fumes, and exhaust issues while driving is a pretty big challenge for both safety and space.

way more cost effective to buy a decent set of lithium batteries.

[allen_dodge]

for your purposes it sounds like that would be the case. I just had an image in my head of a very small streamlined trailer with a generator for road trips as a range extender, but they are probably not worth it for what you are doing. The vw concept I saw used a 2 cylinder turbo diesel and 7 speed gearbox, with lithium batteries of course, but ultra low drag coefficient (.17 i think? have to double check) and carbon fiber skeletal chassis with plastic body panels meant that the energy consumption even with spirited driving was much, much less than what you are dealing with, meaning that less power was required to be generated in the first place. It's actually a very sexy looking machine, especially for something that has rear wheel fairings (sorry aeromodders, i cant help it ) and despite expectations, is surprisingly peppy, AND rear wheel drive. If I could have any car in the world right now, it would probably be that one.

I think you are on the right track with different batteries, i hear li-po has much less sag and the reduced weight means you will need less amp hours, as well as better top speed and acceleration. Keep up the good work

[allen_dodge]

Here's a link for anyone who hasn't already seen this car in the news, not trying to derail this thread but I strongly believe that what we are looking at here is the future. I'll stop talking about it now

VW XL1 Concept - 300+ MPG!!!

I guess the big question is... will anyone be able to afford it?

[bennelson]

In my real-world experiments with expanding a low-budget DIY EV into a "range-extended" Plug-in Hybrid....

It's not worth it to convert a DIY EV to a plug-in hybrid. There's a lot of little things that might work out well if planned from the start, but work very POORLY if shoe-horned in later. Some of those things were already pointed out in a few of the above posts.

I think a DIY Plug-in Hybrid would be a GREAT project, but it needs to be planned as such from the start to really work well.

[jray3]

[/QUOTE] I ran the heater for about 10 minutes. No funny smells, burning, melting or fire. I pulled it apart to make sure and all is well. It looks like the solution for heat was quick, cheap and painless after all![/QUOTE]

I wouldn't expect that duct tape to last even ten minutes. HVAC-duty aluminum-backed mastic tape should be the minimum, IMHO...

[allen_dodge]

Originally Posted by bennelson

I think a DIY Plug-in Hybrid would be a GREAT project, but it needs to be planned as such from the start to really work well.

I agree 100%, what did you use as a test bed when you were experimenting with this idea? I have a deep fascination with DIY EV conversions and the plug-in hybrid seems like a logical step, but I've never actually seen it done outside of the aforementioned Top Gear episode and I'm starting to see why...

[mechman600]

Originally Posted by dtbaker61

having an on-board generator is dangerous, noisy, ineffective, and expensive.

If its tiny, it cannot possibly generate juice as fast as you are using it. running an ICE generator on board, solving the fuel safety, fumes, and exhaust issues while driving is a pretty big challenge for both safety and space.

way more cost effective to buy a decent set of lithium batteries.

You nailed it on all three points. I would need at least a 10KW generator to propel the car indefinitely. Go price one of those out - probably in the $3K-5K range for a diesel.

Originally Posted by bennelson

Project is looking good!Great Job!
-Ben

Thanks, Ben. You are definitely in the credits as inspiration provider!

Originally Posted by allen_dodge

I think you are on the right track with different batteries, i hear li-po has much less sag and the reduced weight means you will need less amp hours, as well as better top speed and acceleration.

I agree 100%. I long for a LiFeP04 pack in the worst way. It's just that, well, my pack was free and continues to be free as batteries die and I replace them with more free ones. The point of this build is super low budget, so free wins. I agree that lithium is the cheapest battery you can buy (cost/cycles), but not as cheap as free!

Originally Posted by jray3

I wouldn't expect that duct tape to last even ten minutes. HVAC-duty aluminum-backed mastic tape should be the minimum, IMHO...

The duct tape is only on the inlet to the blow dryer guts to act as a dam and force all blower fan air through the coils. I disassembled it today to inspect it and it looks like the day I stuck it in there.

I have been pre-heating with a 120V space heater that turns on with a timer this last week for about 45 minutes before I leave for work. My EV heater nicely maintains the coziness all the way to work.

Today I installed my poor man's BMS - a remote set of six volt meters that I can plug into the car to monitor each 12V pair while I drive. On my commute home I quickly found out that I had a dud pair. So I split them, load tested them and found the culprit. Back to the battery shed tomorrow, I guess.

I will post pictures of the "BMS" when I get a chance. It's pretty epic!