Ben Nelson's Electro-Metro Build thread

[sonic]

Imagine driving into a pot hole or up on a curb stone, that impact would rattle the transmission quite a bit. Your heavy motor and only the turnbuckle to hold it. It's more a question of when it will break, not if. Sure will be a shame when it does.

Yeah, you're right about the air heating to the battery's. One step further would be to rout warm water around the packs directly. Much easier to do and no loss since the water are recycled to the heater again. Only a extra cycle pump, with an switch inside. That's the way to go I think.

[Tango Charlie]

Had to chuckle at the pics in post #863. That pretty yellow paint job got kinda beat up after removing/reinstalling the motor and transmission so many times! How many times DID you do that, anyway? I think I would've given up after the third time! Well, maybe not, but it's gotta be discouraging.
Kudos again on the car.

[bennelson]

After charging from yesterdays ride, I calculated energy use as 322 watt-hours per mile, or roughly the equivelent of 115 mpg, my worst yet.

Also, figuring that it took just a hair under 3KWhr, that means that at 72Volts, the batteries actually hold 41.6 amp-hour capacity.

But that was running the batteries down too far. If I figure I only want to run the batteries down half way, that makes the number 20.8 amp-hours. That's on batteries that are rated for 95 amp-hours!

Of course those batteries are rated at something like a 20 amp drain rate, not the 100 amps I am typically using!

If I really only have about 20 amp hours to use, and the car averages 100 amps to cruise around, that means I get about 1/5 of an hour of run time. That's 12 minutes of driving! At 35 MPH at 1/5 of an hour is 7 miles!

I really shouldn't be driving more than 7 miles in the winter! Ug!

I will have to try this again on a day with similar weather, but with preheating the car, and see what difference I have in range and energy use!

PS - One of the reasons I got such a good deal on these batteries is that gel cells are known to drop range A LOT in the winter. These batteries were originally pulled from an NEV and were replaced with a different style with better cold weather characteristics. I knew I would have poor winter performance, but ACK! This isn't good!




PS: Thanks Terry. You are right, I did end up taking the motor in and out several times. That's what I get for learning as I go. One time I installed the motor, only to realize I would not be able to turn left because of the tailshaft!



If I ever have to pull the motor again, - OK - WHEN I have to pull the motor again, maybe I can take it apart and powder coat it. The motors rebuilt by Jim Husted and other EV modders look SO nice, and part of it is the paint job.

[RarestAce]

would a battery blanket like this one Phillips & Temro Blanket-style Battery Warmer : JC Whitney: Auto Parts & Accessories help with your range at all?

[bennelson]

I think battery blankets like those would help.

Too bad those cost more than I spent on the batteries! ($40 each x 6 = more than I want to spend!)

I have played around a little bit with "pipe wrap tape". That electric strip stuff you wrap around your pipes to keep them from freezing.

Maybe I need to try that stuff again with a timer and a thermometer....

[TheSGC]

I just got my EV legal too, and I have also noticed really poor winter performance. I am building an insulated box and doing range testing and it really helps if you get about an hour or two of charge before you drive. Charging heats up the batteries, so two hours before I go out I drive up and down the driveway to clear the battery surface voltage and charge it again. I give it 1.5 hours of charge, then I plug in my ceramic heater for the last 30 minutes to defrost and heat the car.

I just installed a PakTrakr installed and will start recording DOD, Voltages and mileage. I did the first EV-instead-of-ICE family trip tonight and my dad was pleased. I am going to adjust more settings on my Kelly controller to increase the acceleration.

Originally Posted by bennelson

I think battery blankets like those would help.

Too bad those cost more than I spent on the batteries! ($40 each x 6 = more than I want to spend!)

I have played around a little bit with "pipe wrap tape". That electric strip stuff you wrap around your pipes to keep them from freezing.

Maybe I need to try that stuff again with a timer and a thermometer....

[TomEV]

Winter (such as we have in the Bay Area) has affected the performance of the Citicar as well. With cold batteries and defroster use, my eMPG has moved from around 250 wh/mile to 275 wh/mile.

As a side note to my brush advance experiment, it didn't make it any faster, just caused the wh/mile to get worse - 301 wh/mile for the two weeks it was used that way...

[Daox]

I recall reading that some guy was using a water bed heater to heat his battery compartment.

[Christopher Jordan]

Originally Posted by TomEV

Winter (such as we have in the Bay Area) has affected the performance of the Citicar as well.

Maybe it is contagious- I have had terrible distance abilities with my 48V CityEL, and my 36V E-Pod just died yesterday. Been a terrible winter 75 miles south of the bay area too. Finally get a clear and sunny day and my garage is full of dead vehicles. So much for my new year resolutions!

I looked at a Zenn yesterday since they sell those here, but I don't know if Xebra is sold around here anymore. I hope they return- improved, I think. Those might make it through a winter better than mine have!

[MPaulHolmes]

Originally Posted by TomEV

As a side note to my brush advance experiment, it didn't make it any faster, just caused the wh/mile to get worse - 301 wh/mile for the two weeks it was used that way...

Did you advance the brushes and increase the voltage, or just advance the brushes? What I've heard is that you advance the brushes as you increase the voltage. The voltage increase should result in an increased top speed, and the brush advance makes it so the voltage increase doesn't ruin the brushes (I think. I don't really know. I've never advanced my brushes before)