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

[Daox]

As far as I know all lead acid batteries suffer from sulfation.

[jakobnev]

Re: Accesory battery.

You might find a switching 13.8v power supply that you can run straight off the DC from your HV-pack. (So no need to charge it separately anymore)

[mechman600]

Originally Posted by jakobnev

Re: Accesory battery.

You might find a switching 13.8v power supply that you can run straight off the DC from your HV-pack. (So no need to charge it separately anymore)

I have looked long and hard for such a DC-DC converter with enough power. $150 gets a decent one. $400 gets a really good one. But that's too much, in my opinion, considering my current solution is free so far. Plus, I would still need a 12V battery anyway. Maybe a smaller one, but still.

My car uses 32 amps with everything on - wipers, heater fan, lights, brake lights, etc etc. That's 384 watts - more than any cheap DC-DC converters out there. The brake vacuum pump uses an additional 10 amps when it cycles on. Using LED lights here and there would bring that number down by maybe 10 amps which probably isn't worth it for the $50 for those. But...LEDs would be cool so I might buy a whole bunch of eBay (Chinese) ones anyway...

I am also thinking of installing a 15-20W solar panel. I'm not sure if that would be enough though. I'm going to try out my laptop charger first. It's just sitting there doing nothing anyway. If it goes up in smoke, it will have been an interesting experiment anyway.
If that doesn't work, then maybe a solar panel. Solar panels at least create the illusion [and confirm] that my car is very green.

[NoD~]

Hey! nice job. I've been looking into electric conversion for some time (I travel under 4 miles each way to work, so short commute as well).

Anywho, saw your line-loop on your power steering. A word of advise: convert it! I drove with a line loop for YEARS. It's easier than having a power steering pump hooked up w/o a belt, but it's still quite the challenge w/o movement. I had to rebuild my engine, so while I had it out, I completely re-did all the suspension components (for peace of mind)... while I was at it, I dropped the rack, pulled it all apart, took out the piston, greased it well, sealed it up, and re-installed it. The results were definitely worth the effort! Two handed, I can turn at a dead stop w/o too much of an issue. Just barely any rolling movement and 1 handed is very easy. At anything over 5MPH, it's pretty on-par with power steering, IMO. Once in a while, I drive a car w/ power steering and the only time I notice it is at a dead stop or VERY low speeds.

There are several write-ups out there on how to do it. Can't say the same for ALL racks (I followed one that wasn't for my car specifically, but everything was very much the same), but the mechanics seem to be pretty standardized. It's more just messy and time consuming that it is difficult. Only cost for me was the grease (I went w/ synthetic grease).

On solar panels... you can buy just the cells themselves and wire them up in series to get whatever voltage you desire. Coupled with a charge controller, of course. Custom build for your entire roof, if you wanted. Hood, trunk... Though, that many square feet (with time and money involved) is likely only to get you 100-300watts of juice in the sun.

Anywho, keep up the good work!

[ctgottapee]

Originally Posted by NoD~

Anywho, saw your line-loop on your power steering. A word of advise: convert it! I drove with a line loop for YEARS. It's easier than having a power steering pump hooked up w/o a belt, but it's still quite the challenge w/o movement. I had to rebuild my engine, so while I had it out, I completely re-did all the suspension components (for peace of mind)... while I was at it, I dropped the rack, pulled it all apart, took out the piston, greased it well, sealed it up, and re-installed it. The results were definitely worth the effort! Two handed, I can turn at a dead stop w/o too much of an issue. Just barely any rolling movement and 1 handed is very easy. At anything over 5MPH, it's pretty on-par with power steering, IMO. Once in a while, I drive a car w/ power steering and the only time I notice it is at a dead stop or VERY low speeds.

There are several write-ups out there on how to do it. Can't say the same for ALL racks (I followed one that wasn't for my car specifically, but everything was very much the same), but the mechanics seem to be pretty standardized. It's more just messy and time consuming that it is difficult. Only cost for me was the grease (I went w/ synthetic grease).

What would the search terms for this be, or the slang name for this type of conversion?

[NoD~]

"convert power steering rack" google search gave me this one...
Flyin' Miata : Tech: 1.8 conversion

I can't find the exact one I got most of the ideas off of, but this one I linked isn't any different, really. Again, they all seem to be very close, just likely different sizes/tools/etc here and there.

[mechman600]

I spent much of the weekend messing around with my charging situation.

First off, my round 2 Kelly charger arrived, this time with a lower charge voltage of 84.0V (instead of the previous 88.2V). Giddy as could be, I swapped it into the place of the old one and plugged 'er in. And VOILA! Nothing. Green light on, meaning it is "fully charged". That shouldn't be when pack voltage is at 75.2V. It should charge and then cut off to float no matter what. So I took the Electric Booger for a hard run around the block. Now the pack was at 74.2V, so I plugged 'er in again: NOTHING.

So Kelly #2 is DOA. After a few emails, Kelly wants to send me another one.

I then meticulously topped up all batteries individually with a 12V charger. Turns out that my batteries have gone WAY out of balance. Some batteries took quite a while to top up. Then I plugged in the 88.2V charger and watched voltages.

What I have concluded is the three odd ball AGMs in the pack have a different internal resistance than the rest, so the pack is unable to keep balanced. After topping up all batteries, these rose to about 13.8V while the rest stayed around 14.8-15.3V. Before topping up, the three odd balls were usually the way-too-high ones. So unless I purchase three more brand new AGMs to match the rest, balance will always be an issue.

I looked all over the internet to find 12V automatic microprocessor controlled chargers that I could buy six of. This way, balance will once again not be an issue. I have one Schumacher 12/8/2A charger. But for some reason it charges batteries to a much too high voltage cutoff - 15.2V on "standard", 15.5V+ on "AGM" and 14.9V on "Gel". Plus, it only puts out around 5A when voltage is above 13.5V. And you have to actually turn a Schumacher on each and every time you plug it in. That would get annoying fast.

I did find a Chinese 12V/10A charger with no buttons - just LED indicators like my Kelly. But do I really want a bunch of chargers purchased online from China?

I decided to ditch efficiency for reliability. I have already sold 5 of my 6 previous 12V chargers I was using. It turns out that Canadian Tire has a 1/2 price sale on 12V/10A chargers, so in I went to buy 5 chargers. And installed them.

These chargers are a newer style than my previous ones. Heavier. Much larger. It took some doing to make them fit. Some testing revealed they are slightly more powerful than the one "old style" charger I have left. Tomorrow's charge at work should confirm this. If this is indeed the case, I will have to buy one more to complete the set.

OI. I am sick of chargers.

Merry Christmas, everyone!

[TheSGC]

My first EV started out with 8 of those Schumacher 6A chargers and it was a pain to turn each on and adjust the settings every time it was plugged in. The I got an old school K&W BC-20 which did good for years, but it did not have a shutoff so I had to time my charges every night.

Lead acid does drift quite a bit over time, you are really never going to have them balanced, except for maybe for the first 30 or so cycles when they are brand new. Individual chargers for the AGMs is definitely going to be your best bet in the long run, unless you get some shunt regulators on your batteries.

My new EV has an Elcon 2000+ and I have been pretty happy with it. It was pretty cheap for a 110/220v charger and it has an automatic shut off and integrates with my BMS so if an HVC happens the charger will shutdown.

[mechman600]

Timing your charge is almost as annoying as having to turn individual chargers on. I just want to be able to plug in and walk away, which is what I have again with individual chargers.

On "Standard" mode, they cut off at 14.4V and on "AGM/Deep Cycle" mode they cut off at 15.0V. Since they obviously do not have temperature compensation, I can use the higher V setting for cold weather (5C and below) and the lower V setting for anything warmer than that.

I do not understand why the Schumachers and other microprocessor chargers cut off at such a high V. I cringe just thinking of my poor AGMs venting because of it.

Oh, and my new Mastercraft chargers are quite a bit more powerful than my last batch of Mastercraft chargers, even though they are rated for the same amperage. They are much heavier, which is mostly in the transformer, allowing higher current output once voltages get above 13.5V.

[mechman600]

Clark Griswold style!
Don't worry - it's less than 1000W divided amongst all these cords.