Ben Nelson's Electro-Metro Build thread

[bennelson]

She didn't fit in the car either.

Had to be "modded".

[EVDRVR]

Originally Posted by bennelson

Right after that, I put it into second. I think 30 mpg is the fastest it has gone so far in second.

Ben,
Just how fast is 30 mpg in 2nd?

Have been reading the saga a little at a time. I sort of picked up at the end. I'll give you some charging info on the gels along with some battery opinion and a comment about vacuum pumps. (I missed any particulars as to your charger and history so forgive me if I wasting words here. Sure not trying to insult anyone or be redundant.)

Deka says charge to 2.30V to 2.35V volts per cell for the gel batteries and a float of 2.25V to 2.30V. The charger in my Force was profiled for the upper end 14.1 volts per battery during charge and the lower 13.5V during float. Charging voltage needs to be temperature compensated to avoid over and undercharging.

As you know if you have a 10 gal gas tank and you use ten gallons you only need to put back ten gallons to fill it up. Batteries don't work that efficiently and it gets really complicated as to how much, how fast, and how you put the charge back into the pack. It is a subject of great complexity and has many right answers. It is the wrong ones you want to avoid.

It gets even more complicated when you put a Pba battery in a EV. A EV is pretty much living hell on a battery. You'll almost always be operating at around the 1hr rate or less. Unless you have some monster batteries that 100ah rating you mentioned is likely at 20hr rate or at least 5.

Solectria runs a overcharge of 10% to get a full charge using the charger that is in my car on the 13 battery string. They have run as high as 15%- 20% in some other profiles. This is a balancing charge.

As your string is shorter you might want to use slightly less. Voltage balance becomes a serious issue as the string gets longer and or the amp load on the batteries gets higher. High amps and long strings increase the "evil" outcome. Solectria overcharged the grp 27 gels in the Force @ 3 amps to a max voltage of 15 volts per battery. You do not want to go to 15 volts unless you have a sophisticated charger. Observe the 14.1V limit.

Most people I know would advise against using a Deka Gel battery in a EV unless it was going to be limited to a fairly low amp load almost all of the time. Deka gels will last a long long time in the right conditions, low amp loads being one of them. The Force operates almost all of the time below 200 amps and predominately below 100. At 30 mph it is using about 30 amps. Higher voltage means less amps and the AC induction motor by design requires less than a DC motor.

Ecomodder's drive smart to save gas, EV owners drive smart to keep the load off the battery. Pba batteries are like little children, how they are treated every day determines the outcome.

You can go out a "hot rod" a tank of gas without any effect on the new fuel. What you do to a battery pack is there until replaced. So when you hear individual results about battery performance being good or bad a lot can be attributed to the throttle actuator.

Gel batteries need a rather special break-in or unrepairable damage can be done. Two gentle cycle's when new best done with a load other than the motor. Then really baby them for awhile. The return is a much longer life and better capacity. Solectria recommends a low amp discharge to a about a 30 ah discharge followed by an immediate recharge. We use the heater in the Force. It draws a 10 amp load and this takes about 3 hours. Ideally do this twice before operation under power in the car. Then the you should drive gentle (less than 150 amp load and consume no more than 20 AHs on a grp 27) everyday for another 10 charges to maximize longevity and performance.

Vacuum pumps.

You can buy a number of pumps made just for use in a EV. This might be a place in which to spend some money if your not going to be the only driver. When we really know a vehicle well we can forget other don't, and they might have false expectations.

With a electric pump you really may not need a vacuum cannister. Sort of depends upon pump size verses brake booster. My vehicle simply has about 2 feet of hose wrapped around the pump. Remember your never going to be in a zero vacuum WOT condition with the EV. When the pressure drops the pump comes on, pressure up pump off.

Unless the a/c is on, the vacuum pump cycling once when I turn the key is the only sound to be heard.

My pump cycles on after about two pumps of the brake pedal. Off again in just a few seconds.

A friend is turning a 90's Avanti into a EV and using a Harley tranny, a Corvette rear end and a 9" mid engine mounted motor. This is after a body off restoration to kill the rust. He bought a Metro to convert but decided the Avanti was what he really wanted to do. There is always deeper water.

Keep up the good work, it sounds like your having a good time.

Stay charged up and if you haven't met our Pba EV friend/nemeses "Peukert" give him a Google.

EVDRVR

[bennelson]

Originally Posted by EVDRVR

Ben,
Just how fast is 30 mpg in 2nd?
EVDRVR

Well, in my truck it's only about 15 miles per HOUR, but in the EV car it's about twice as fast.


Thanks for the gel tips, especially how to break them in, I haven't heard the specifics of how to do it before.

Or ordered a used charger from a fellow EVer.

It is a charger out of a Zap Xebra from when they were using these same batteries. The charger specs out at 84.6V peak voltage and 15 amps charge rate. 84.6 comes to exactly 14.1 volts per 12V gel battery.

I have also met Mr. Puekert. He lets me drive for 30 miles on my motorcycle at 25 MPH, but only 20 miles at 45 mph

[bennelson]

Here is the results of last night's work.

On the left is the original coupler, cut, trimmed, and rebuilt.

On the right is a NEW pair of lovejoys which I picked up in case we needed to use them. The machinist was able to re-use the original parts, so I can stay on budget by returning the new ones to the store!





Yes, I know the spider on the left isn't looking so good. THAT part is NOT getting re-used! But that's what I get for driving around the neighborhood with an improperly mounted motor!

[Clev]

Originally Posted by EVDRVR

With a electric pump you really may not need a vacuum cannister. Sort of depends upon pump size verses brake booster. My vehicle simply has about 2 feet of hose wrapped around the pump. Remember your never going to be in a zero vacuum WOT condition with the EV. When the pressure drops the pump comes on, pressure up pump off.

If you have the room, I'd always recommend a vacuum reservoir so the pump cycles less often. And, being at a minimum just a length of PVC with some caps on the end, it's probably the cheapest part of an EV.

[bennelson]

Hey everyone.

I was out of town for the weekend and when I got back home, I found this on my doorstep.







Its a 15 amp, 72V charger DESIGNED for use with true gel-cell batteries (14.1V max.) which I bought used from an EVer in Florida.

Looks like it should be pretty easy to hook up. The only odd thing is that spare little black and white wire. Supposedly, it is designed to run to a relay so that you can't drive off in your car while charging. I will have to hook it up and check it with a multimeter to see if it is designed for 12Vdc, 120AC, and if it is normally open or closed.


EDIT: I know there is no sense of scale in these photos. The charger is pretty big! It's about a foot long and weighs 13 lbs.

[bennelson]

UG.

Tried doing some more work on the car. (yep, raining today too.)



Very frustrating. I don't have a real engine hoist. The motor is too big for me to even move by myself.

Still waiting on getting the end of the motor machined.

Tried wiring up the charger - can't figure how to hook it up. The DC part is real straight forward, but the AC part is weird. It has three wires - red, black, and green! That's not right for 110v AC OR 220 AC!!!

I used the continuity tester to see which terminals connect when you turn on the power. I checked to see that those are the ones power goes to. Plugged it all in, and I just get an "Fault" error!

GRrr. Gr... grrrrr...



Actually, I did get SOMETHING done. I drilled holes through the rear battery rack into the body of the car and got it bolted down. I used threaded rod to connect a top-front angle iron to the rear bottom angle-iron, I tightened it down. That should at least keep the batteries from sliding around.

[bennelson]

Don't you hate it when you just keep banging your head on a problem, and then later you have a revelation?

I wired up the AC connection on the charger, but could only get a "Fault" light to come on.

It has taken me almost a day to realize that the error light isn't talking about the AC connection, but rather the DC one.

I was bench testing the charger to test it out before trying it in the car. Turns out the charger HAS to be hooked up to the battery, or it gives you an error!

Once I DID hook it up to the car battery pack, plugged it in, and turned it on, the fan powered up, and it appeared to be charging the batteries, pulling about 120 watts AC.

The batteries were mostly charged, so the charger must have been already into the HighVoltage/LowAmperage stage of charging.

I will need to check on it later to see how many volts/amps it charges with and see what the total KWh's through the Kill-a-watt is.

[bbjsw10]

Congrats on figuring out charger. And yeah I love those days when you run in circles chasing your own tail. Nerve wrecking at times.

How much does that motor weigh? Looks heavy.

P.S. you should look into gun-metal paint for your wheels when you get everything straightened out on the car. That would look great with the black. And keep up the great work.

[MPaulHolmes]

I guess that makes sense about having it first hooked to the batteries. My bike charger reads 'full' if I just plug it into the wall without first hooking it to the batteries. It must be a standard amongst chargers.