Wednesday, August 26, 2009

The Adventure: Home

My EV was basically fully charged when I left for home yesterday. The trip was pretty uneventful, but I ended up missing on of my planned short cuts, so I had to drive through some 45 MPH streets with mild hills, into the center of town, adding another 2 miles to my 16.5 mile commute. The EV did well, until the last hill home. I dropped to 25 MPH going up the hill and I had to pull over cause some guy was riding my tailgate. It was a 30 MPH hill, so I there was really not a big deal... Oh well.

I definitely need the new Synkromotive controller and to not miss out on my shortcuts. I probably would not have had much trouble with that final hill if I had an extra 10 Ah of juice in my pack to contend with. Actually, I am going to look it up to see if it was my batteries getting sort of low, of the controller not giving the juice to go up.

EDIT: It must be both the controller not giving the juice properly since the calculator shows That 230 motors AMPs are needed and only 165 battery AMPs to climb the hill, and an extra 10 Ah of power would be nice since climbing that hill at 30 MPH will use 3.75 Ah of pack.

Tuesday, August 25, 2009

The Adventure

The Adventure actually began yesterday when I decided to take a test run of the route I picked out for my EV ride to school. So with MapQuest in my hand, I take my ICE and try out the route. I get a whopping 2.6 miles when my drivers rear tire blows. I pull into the nearby school parking lot like 100 feet away and find a HUGE tear in the tire, like someone took a sawzall too it! I tried to remove it but the sucker was rusted on so a call to AAA was in order and they came and used a sledge hammer to get it off. Put on the Donut and went home. I felt like I was towing 3000LBs with that donut!

Anyways, I needed new tires and today I find out I also need new brakes and I had a stuck caliber (which I thought needed replacement a few months ago). So with my ICE in the shop, I had to try out my route with my EV, pretty much going blind.

So I did take my EV, and I got lost. When I finally made it to school I had driven 18.4 miles, 2 miles farther than I needed too. I had power left, and the pack voltage never got below 84.4 volts under heavy acceleration and at rest was over 96 volts when I finally parked in.

That was only part of the Adventure. Yesterday I got my access to the lot with the school's EVs, the access pass and sticker. So when I arrived today at 8:15 there was NO PLACE TO PARK! I had a backup plug in another lot so I am currently charging there. But I really need a spot in the EV lot, so some EV rearranging is needed, and since they are all small Geo Metros, it shouldnt be too hard to get a setup that works for everyone.

Now I am prepping for the third part of this Adventure: going home. The Civic is on the charger and hopefully will be done when I am ready to leave. I cranked up the charging current a bit just to hasten it.

Thursday, August 20, 2009


I just got back from Walmart and exchanged the two bad batteries. It took longer than I thought, mainly because the price of the MAXX29 have increase $10 each since last year, so it took the Customer Service rep a bit to figure out what to do.

Anyways, the new batteries are fresh off the pallet with an August 09 date. I put them into the battery trays, but I haven't strapped them down or wire them up yet, that will be tomorrow's job.

Before I do that, I am going to charge the two new batteries with the smart charger, then hooked them into the pack and give it a few minutes with the K&W. Then comes breaking them in with a couple runs doing 25-30 MPH around the block should do it. There is only about 25 cycles on the pack, and it's OK to add/change single batteries as long of they are less than 50 cycles difference between them, so I should be fine.

I am still working out the finer details about getting my plug at school, but I am hoping to get things finalized very soon before all my saved money gets spent on gas again. It's costs me $3.00 a day to commute in my ICE, and only $0.60 for the EV, so it's quite a savings!

Under Load

I MapQuested a trip around town, using 35-50MPH roads with hills and drive 16.5 miles just to make sure I could make the trip to school. I found out that I have two really bad batteries. After 15 miles of driving, the PakTrakr starting to flip out saying that A1 nd B1 needed charging.

So I set the PakTrakr to monitor the batteries in question and found that under load, A1 was sagging to 10.4 volts and B1 was at 7.5 volts! The other batteries were only sagging to 11.2-11.1 volts while driving at 35 MPH. I made it home, but dropped the speed down to 25 MPH to keep the A1 and B1 batteries above 10.5 volts.

I am pulling A1 and B1 today and getting them replaced at Walmart. 18 month free replacement is going to be real useful right now. I kept all my reciepts just for this purpose.

At least I know I can make it the 16.3 miles, and most of the batteries were at 50% when I stopped. And the route I plan to take to school is limited to about 35 MPH and probably less hilly.

Monday, August 17, 2009

Too Many Variables

I decided to try another setting in the Kelly controller, one that would use less battery AMPs, and hence less acceleration. There must be hundreds of different combination's one can do with this thing, and they really don't come with any explanation on what they do.

I went over the mountainous journey, and instead of looking of power required to hold speed, I looked at the battery power needed to climb the mountain. It was quite frightening! I was pulling 250 AMPs for 3 minutes going up, and with some simple math the power it took from the battery pack was: 250 AMPs per Hour/3600 seconds per hour*180 seconds driving time*2 for Puekerts Effect = 25 Ah from the batteries! Thats 1/5 of my battery pack, and that was done three times after 12 miles of driving! No wonder I literrally crawled home! I used up at least half my pack driving 3 miles of mountainous hills, more than I expected. Now I know, avoid that part of town.

I have a few new routes I found using MapQuest that I want to try because they are basically flat, and will get me to where I want to go, hopefully with lots of power left.

Friday, August 14, 2009

The Real Deal

Wednesday night I decided to take the EV out and try out the new cooling and program settings. The acceleration was GREAT and the controller stayed pretty cool. It was supposed to me a 12 mile round trip, but 4 miles in I can to a dirt road (under construction) and bottomed out the EV, cursed and went on. Then after reaching my destination I followed my dad home, asking to skip the dirt road. Well, he did avoid the dirt road and instead took the scenic routes to the mountains of our town! I ended up using almost ALL the battery power going up the hills, and came to a point where the controller went into low voltage shutdown and I was creeping along at less than 1 MPH.

I found that this what was my dad was referring too when the hills slowed him down. I did a battery check, and one was 50% and the rest were between 8% and 40% left! WAY out of balance!

I have used the single smart charger to bring up the lower batteries, and next I am going to set my K&W to do an equalizing charge on all the batteries. If this doesn't work, I am going to replace the entire pack with a new one, all under warranty. I also did try out the prototype BMS and it worked great after some minor software changes. Hopefully I will get a picture soon.

Tuesday, August 11, 2009

Cooling Off

I decided to do some more controller playing today. I added two CPU fans to the heat sink of the controller, and changed the controller program settings to Torque. Now it should give all the power it can, and with the extra fan cooling it seems to be doing a little better. I won't really know until my Dad takes it out again and reports back on those hills. My 7.7 mile trial run with the improved setup yielded great results and the controller heat sink was considerably cooler. And it was 85 F with high humidity out today, quite nasty for working on the EV, but I did it anyways.

This Friday is the meeting about getting plugs at school and I also hope to drive it 17 miles and see how it does. I might mapquest a route to go back and forth and see what happens.

Thursday, August 6, 2009

Heating Up

I have not done much with the EV since I was away on vacation, but I do have a few things going on.

First, I started my Battery Management System. I have one prototype made up and will be trying it out soon. It's a Shunt type regulator with a programmable PIC processor and I have it setup for a 12 volt flooded lead acid battery. It also has a basic State of Charge meter, 0%, 25%, 50% 75% and 100%.

I also have a meeting next Friday about getting my plug for my electric car at school. I have been trying to get a plug for about 8 months now. This time instead of asking for a plug and getting clueless responses, I went out and found a spot on campus that would be great for electric vehicle charging, gave a picture to the right people and get a meeting two weeks later!

Now the controller. I am on the waiting list for the next batch of Synkromotive Controllers, and it might take more than 4 weeks! I have been going over more data from my EV driving, trying to get the most out of the Kelly, and I think if I add some more high powered fans to the bottom heatsink, it might make the hills better. There are these two hills in my Dad's route that the car really slows down, and they also happen to be at the end of his commute. The other day when he came home I decided to check the controller's temp, and the top casing was fine where I put the CPU fan on, but the massive heatsink was HOT! I have no forced air cooling over it, so that is my next job. I have a whole ton of high power CPU fans, so I will try those out. I am also going to take some TEMP readings today when I take the EV out and try some massive hills.