Ben Nelson's Electro-Metro Build thread

[bennelson]

I still have a few more things I need to do on the Metro to make it a reliable daily driver. So, it's still not done yet.

I don't have any heated indoor space for working on vehicles, so not a lot is going to happen this winter.

I think the Citicar is going to be a spring project.

[bennelson]

I took the car to my office today, then to the bank and credit union.

Showed it to my business partner. He was pretty impressed with it overall.

I mentioned what I was driving while talking to the bank teller. She couldn't see the car parked from where she was in the bank, so I rolled past the drive-thru on my way out!

It's raining here and the car is charging in my driveway. Can you recharge an electric car in the rain? We'll find out.

The charger is protected by the 20-amp GFI outlet I installed in my garage special for the car. I have the KillaWatt plugged into that and then the power splits to go to both the 72V and 12V chargers. (That way ALL electric use in the car is tracked, and GFI protected)

I will check later if the GFI popped or anything else weird happened.

I suspect that driving an electric car in the rain uses more energy, because the 12V system has to handle lights and windshield wipers.

[bennelson]

Here's another video update.

http://www.youtube.com/watch?v=hNNDgBDw_OI

PS: I am very wet right now.
It was raining pretty hard, and my wife and I drove over to a restaurant for dinner. I do need to clean the windshield! It's fine for day, but bad glare at night!

My Metro also does NOT have the electric defroster in the rear hatch window. I sure could have used it tonight! In front, I just ran the defroster blower (cold air, no engine heat in this car anymore, remember?) and that worked fine for clearing up the windshield.

I don't think my 18AH SLA 12V accessory battery liked having me running the lights, windshield wipers, and defroster all at once off of it!
I will need to instal a bigger battery or DC/DC converter for the winter.

It also wouldn't hurt to have a dedicated 12V meter strictly for the accessory battery.

I'm just testing all this stuff out so you guys don't have to!!!


PS: So far the GFI hasn't tripped

[bennelson]

The GFI never tripped.

I both charged and drove the car in the rain (at night) with no problems, other than the fact that I don't have a rear electric defroster in this car!

I have the latest numbers from recharging! 4.38 KWh used to drive 14.4 miles. (includes recharging 12V battery) comes out to just over 121 MGPe.

I figure the big hit here is that I was running the wipers, defroster, and headlights, and possibly some additional rolling resistance from the rain.

No problems driving the car. I think my wife is much more comfortable in it now that I have a "real" go pedal and the brakes are automated.

I drove us to dinner last night, and dropped her off for the carpool this morning. (Carpooling has been KILLING her fuel economy - cold engine short trips to the park and ride!)

[TomEV]

At just over 3oo wh/mile, you're doing well! When I first got the Citicar, it used about 370 wh/mile, mostly due to expired batteries but also due to driving style and charging methodology.

While I can pat myself on the back for being 'on top of the list', IMHO there should be some sort of separation between EVs and gassers on the MPG list (some sort of e-mpg or wh/mile list) to better compare apples with apples.

A neighbor gave me an old electric scooter -like thing (a 'Razor Electric Punk') that looks like it should be fun to play around with. Needs a new battery (doesn't everything???) and a relay.

If you want, how about an additional DC/DC converter that you can turn on when using accessories as needed, such as the defroster fan? Not sure if it is doable, but might save some expense compared to getting a new, larger model.

[bennelson]

Originally Posted by TomEV

O there should be some sort of separation between EVs and gassers on the MPG list

I agree. Just put us on the top, and everyone else below!

Actually, my EV motorcycle has NEVER shown up on that list, even though it's about 100 watt-hrs per mile.

I am planning on some sort of DC/DC converter in the future. I have a match to the one on my motorcycle, which is tiny. It's only a 100 watt converter, but maybe I could rig in in parallel to the battery? Or in some other way split power between the DC/DC and the battery?

[MetroMPG]

EV/ICE segregation is coming... really. Kind of overwhelmed with tasks!

[toyobug]

Ben, do you have plans to add some sort of heat for the winter?

[TomEV]

With the 100 watt DC/DC, you could assist an individual system (via the fuse panel) but would probably want to put a large diode (perhaps a 1N1206A) so the aux battery could power the items if the DC/DC were off/inop, and the DC/DC would not 'backfeed' the entire 12v bus through the fuse panel.

The diode will have some amount of loss, however.

With the 100 watt DC/DC, you can probably power about 7.5 amps. I use a 300 watt DC/DC to run my entire 12v bus, (also charges/maintains the 12v aux battery) but I don't have any 12v fans. With everything turned on, the 300watt DC/DC is just about maxed out.

I built a defroster out of a cheap *mart heater. I replaced the 115 vac fan with a 48v computer rack fan, and changed the resistive elements somewhat to make it work. I originally wanted a heater, but it works better as a defroster that is used from time to time. Depending on how your heater box is arranged, you could probably put the heater element inside and run it off the main pack - I hear that many conversions have that kind of setup to keep the defroster functionality.

[bennelson]

I am planning heat similar to what TomEV just mentioned.

I will start with a *mart heater and play with it.

I also have a huge resistor element in the forklift charger that looks like it could work well as a heater element, but I haven't pulled it out to play with it yet.