Ben Nelson's Electro-Metro Build thread

[bennelson]

Check the video again. I think it just wasn't finished processing yet.

I am not really too concerned about the quality of the potentiometer. I am mostly just playing with it - learning, testing things out.

I did specifically get a "linear" one rather than an "audio" potentiometer.

[bennelson]

It seems like there is a lack of information on the internet about charging Gel batteries.

I have not been able to find much info at all.
The battery manufacturer web page says to not charge the batteries at a voltage higher than 14.1 volts and to use a "temperature adjusted" charger - but it doesn't recommend a brand or where you can get such a device!

Trying to find a charger that can be set to a lower charging voltage, I did stumble across THIS ONE


It can be set with a dip switch to limit the voltage to 14V max for charging. It also has three output connections on it, so it could run 10 amps out to each of three batteries. I would only need two of these chargers to charge 6 batts for a 72V system.

Too bad the charger is $250. That's almost half a Forkenswift!

Another thing I would like to look into is if there is some simple way to voltage limit a cheaper charger. For example, if I could simply limit the max out voltage of a 10 amp $30 charger, I could buy a bunch of those and use one each on all the batteries.

[TomEV]

Here is a good paper from Panasonic on VRLA (aka gel) batteries...

http://www.panasonic.com/industrial/...ingMethods.pdf

[MPaulHolmes]

Originally Posted by bennelson

Another thing I would like to look into is if there is some simple way to voltage limit a cheaper charger. For example, if I could simply limit the max out voltage of a 10 amp $30 charger, I could buy a bunch of those and use one each on all the batteries.

You're thinking of the 10amp Harbor Freight ones, huh? Those would be good. I have 7 (8 actually) of the 6amp harbor freight chargers. They go up to 14.3 v, hold for awhile (until the battery is full?), and then drop down to 12.8 and hold it there for awhile, then jump up to 14.3 for a second, and then drop down to 12.8 and hold. All you need is to drop like 0.2 volts, but only on the high part.

Easy way: (would work until the battery is full, and when it drops to the trickle charge level of 12.8, this would still be OK! Because it wouldn't still be providing 10 amps to the batteries. It would be trickling at like 2 amps or less)

You could lengthen the cord, so that it would have a 0.2v drop built into it at 10 amps. Hmm...

0.2v = R*10amp

R = 0.02 Ohms. 14 gauge wire is 2.575 Ohms / 1000 feet. So, (haha! this feels really familiar!)

Length = 0.02 Ohms * (1000 feet / 2.575 Ohms) = 7.77 feet.

So, just add 7.77 feet of 14 gauge wire to each of the 10 amp chargers. When it moves into trickle charge mode, instead of 12.8v at 2 amps (or less), the extra wire would have a 0.2/5 voltage drop, which would provide a trickle charge voltage of 12.76v. That's fine! Maybe the trickle would be ever so slightly less trickly, but I think it would work.

[bennelson]

Well, Tim is over right now and he and I are chopping metal and welding.

Until Tim chopped his thumb. Therefore, we are on break eating pizza while he heals.

I will post some photos soon!

Yea Progress!

[MPaulHolmes]

If you are eating pepperoni, make sure you don't accidentally eat the finger that was severed.

[bennelson]

Nope, it was sausage.

It's now 1:30 am and Tim just left.

We spent HOURS grinding, cutting, and welding; but the lower control arm mount is now bullet-proof! Yeah, it's total overkill, but I got the metal for free, so I am still on budget. (About $900 current total. But with current exchange rates, that might still be less than the Forkenswift)

I snapped a bunch of photos of the welding, so I will be able to post some of those soon.

Thanks again Tim!
(I know you checked this forum the moment you got home!)


I was also at an electric car meeting in Elgin, Illinois last night and saw a cheap-o charger a guy had which might work for the gel-cells. He got it at Wal-mart. Go figure.


1:54 AM - Heres some photos.

Swiss Cheese


Tim is happy with the notch I cut in the metal plate.

Ouch! Tim's Thumb!


Custom lighting rig.


Sturdier than ever! Just needs cleaning up and paint!

Tim - Stop reading this! GO TO BED!

[Tango Charlie]

Awesome!
It's an armor-plated Metro!


Tim, you're hired!

[Daox]

Originally Posted by bennelson

Thanks again Tim!
(I know you checked this forum the moment you got home!)

Nuh-uuuh, I took a shower before checking it.

[bennelson]

OK, finally back home from my EV Marathon weekend.

It started about noon on Friday, getting ready o go meet another EV builder and drive about three hours or so to south of West Chicago.

Long drive to get down there, but it was lots of fun and I got to see three electric pickup trucks, a grease car, a homemade Ford Escort conversion, and a Solectria Force (Metro EV!)



The Solectria was great. It had two mis-matched pairs of hub caps, but they matched on each side. The passenger side had standard hubs and the driver side had full moon caps. Since you could only see one side at a time, it actually looked pretty nice. I think I was one of the few people who noticed the hub caps.

I got back to Milwaukee about 1:30 AM. (My house is 40 mins to and hour west of there!) and ended up sleeping on somebody's couch.

The next morning, it was off to the Milwaukee Hybrid Group meeting. The main part of that meeting was a guy showing off and talking about his plug-in conversion Prius. That was the Prius that was converted to a plug-in at the recent Hybridfest in Madison, Wisconsin.

Also at the MiHG meeting I saw the guy who is building an electric motorcycle who I loaned my "Secrets of EL-Ninja" book to. He said he marked that copy all up and has already bought a NEW copy of the book to return to me.

After the meeting, I headed home, and then hopped on the electric motorcycle to scoot over to my aunt and uncle's house for my cousin's graduation party.

Right after getting there, I got a phone message back from Daox (Tim) saying that he could still come out and help me weld the Metro.



We ended up working until one in the morning on the car. It is now armor-plated and WAY stronger than when it was new. Now I just have to clean it up and paint it.

Slept for a few hours and then headed back into Milwaukee to meet up with a couple other EV builders who sort of have secret meetings to get together and work on electric cars.

We took a look at my motor again and hooked it up to transmission. There still was the bad noise, which you can hear in my YouTube video when I spin up the tranny.

The bad news is that the noise is from the transmission. We took the end cap off it to have a look.



After poking around in there we could tell there was a problem with a bearing. We were able to take some of the end parts off to get a better look.



In this photo, you can see at the base of the main shaft on the right, that the bearing is all slapped out.

I don't know enough about transmission to know where to go next. I think I need to talk to a transmission guy to find out if he can just replace this bearing. Otherwise does the whole thing need to be rebuilt? Do I just need to hunt down a tranny in a junkyard? I don't know. I need to find out.

After I was done at the EV built meet, I headed over to see Swee and help him with his electric trike project. (Look up "Swee's Bio-Hybrid Trike" in the Fossil Fuel Free Forum)
His controller isn't working right. We hooked up mine in place, but it didn't work either. I think there is something a little off in his wiring.

I will have to go back some other time to help him out some more.

Then I had to meet my wife over at a friend's house for dinner, drop the Sawzall back off at my Dad's house and head home, where I am now.

Shwew! Long EV Marathon weekend!