[Ziggythewiz]

Welcome!

Can't get that range on that budget. Just the batteries would be $5k

Forklift motor would help on the budget, as would a DIY controller kit if you're the electronics type.

 

[Sailitaly]

Welcome!

Can't get that range on that budget. Just the batteries would be $5k

Forklift motor would help on the budget, as would a DIY controller kit if you're the electronics type.

I figured the batteries will cost the most. I am definitely going to take the advice of going with a DC Motor first. What type of batteries do you recommend? What if I went with a minimal amount of Lithium batteries in the beginning? I could add more in the future to increase the range. I would rather stick with lead-acid my first go around due to all the extra charging requirements lithium batteries need, let alone the cost.
I like the bug. I am going to end up giving this conversion to my daughter when she turns 16. I have a few years to make it safe and reliable though. Thanks again for the input.

 

[onegreenev]

I would rather stick with lead-acid my first go around due to all the extra charging requirements lithium batteries need, let alone the cost.

Actually lithium are about the easiest to charge. Very simple. Go lithium from the beginning. I have been down the lead acid road and you will be disappointed and you won't be getting those distances with lead. If you must, save the money to do it right from the beginning. Its easy to convert but the batteries do cost a bit up front. You still have lots to learn but we will be very happy to help you on your way to a fun cool electric car conversion. Have you checked out http://www.evalbum.com ?

You should do a search on conversions like your looking to do. Even conversions that are not like your project will give you lots of information. Components are about the same no matter what car.

Go do some reading and enjoy the conversions others have done.

Pete

 

[Sailitaly]

Pete,
Thank you. I am reading the Lead VS Lithium blog so I will get back to you on my decision. I don't like the weight of lead acid but aren't they more cost effective since we don't know the true life of lithiums/LiPo yet? Yes I have lot's of research to do.
I actually came across an old but still great treadmill and have a complete go cart frame with wheels. Since I don't get the Accord until mid Sept, I am seriously considering turning this ICE Go Kart into and EKart. This way I can understand the build on a smaller scale before jumping right into a car conversion. I don't know whether the Treadmill motor is AC or DC just yet. Thoughts?

Justin

 

[Siwastaja]

I don't like the weight of lead acid but aren't they more cost effective since we don't know the true life of lithiums/LiPo yet?

This is wrong -- we already know from experience that the LiFePO4 cells will outlast two sets of lead which will make it considerably cheaper already.

Also, according to research these cells will most likely outlast three sets of lead. It's well possible they can do even more than that.

But yes, there are always risks with anything. The risk with lead acid is just 100%.

A LiFePO4 pack now costs approx. 20-50% more than a similar lead pack, but this is only the upfront cost.

It simply doesn't make sense to buy lead acid anymore, which is the most expensive and the worst in performance at the same time. Lead acid works very well in large packs in stationary applications.

 

[Ziggythewiz]

What if I went with a minimal amount of Lithium batteries in the beginning? I could add more in the future to increase the range.

Sounds good. I'd recommend doing a small lithium pack for starters. you can do a 120V 40AH pack for ~$2k...then add on.

I started with cheap lead marine DCs ($800) then upgraded to golf cart batts ($1400), added some lithium as a booster, and the next step is to double the lithium and ditch the lead.

Lead's certainly the cheapest way to get started, but it's not worth the weight and hassle.

 

[Sailitaly]

I am sold. No Lead Acid for this build.

 

[Sailitaly]

So I am going to go with the Lithium right off the batt. I appreciate the passion from everyone "emphatically" telling me to go with Lithium. I have read about 30 different vehicles build blogs online and even though a lot had Lead Acid, most had mentioned they wish they had gone Lithium right off the bat. I am going to do lithium, but I am going with a small amount first.
I will be starting a new thread tomorrow with some pics of the GO Kart build. I haven't figured out whether the Motor is AC or DC yet but as soon as I do I will be sure to let you all know.

Thanks again and keep the advice coming,
Justin

TREADMILL PMDC SPECS
1.75 HP CONT at 100 VDC
22.3 amps
Class H
CW Rotation
2.9 HP

Plus I am picking the FREE Honda in 4 weeks!

 

[TEV]

100 VDC = 100V DC so it's a DC

 

[Sailitaly]

Yep. Probably NOT going to do a Go Kart build with this. Money will be saved for Honda.
Anybody have any info on those new Endel Batteries? They look good. They come in modules of approximately 43 volts, 33-35AH.
I am a little confused how the AHs apply. I know the math but when applying it to a DC Motor, how can you tell the average of range you might get based on the battery setup and the motor you are using?

 

[Sailitaly]

I am getting the donor car today. Pictures tomorrow.

 

[Sailitaly]

So, I finally have the car and here are some pics. I had to get it street legal so I could start driving it. In the meantime I am scavenging the junk yards for a FL motor. Please let me know what you think about an EV convert for this car.

So the Admiral "wife" said I have to get all the parts and pieces before I start this, so we don't have the car sitting around for months and months. Fine by me, but it is going to take me a few months to order everything. But first I have to find the Motor. If I can't find a free one in 30 days I will more than likely end up buying one.

Justin

SPECS: 1996 Honda Accord EX V6 SDN AT CURB WEIGHT 3285

 

[Sailitaly]

So I have the car and I have set up a meet up Group called VB EVers. If you are in the Hampton Roads area and want to come out and help with the conversion the information is here. Join us and let's learn together. I will still be posting the entire build here with pictures for all to learn from.

Justin Mayo

http://www.meetup.com/VB-EVers/

 

[Sailitaly]

So here is my plan for the accord:

HPEVS AC-51 or AC 75/6. I am not sure if I will be happy with the 51 but this is a commuter car so I am not looking for blistering speed.

If I go with the 75/76 I'll get 46 CALB 180AH Lith Batts, 144v.

I am planning on keeping the Automatic transmission. This of course is the part that worries me the most.

Still looking for advice on DC-DC converters?

Also looking for advice on on-board charger. I like this http://emotorwerks.com/products/onl...e-12000-ev-charger-component-kit-no-enclosure

I haven't calculated the range I am going to get yet with this many batteries, but I estimate it should be around 75 miles. I am not going to be doing HWY speeds, I think the most I'll hit is 50mph.

I will be posting pics of the "gutting" over the next few weeks.

Justin

 

[67BGTEV]

U can go close to 70mph. Yes, u should get 75miles @55mph with 10℅soc remaining.

 

[Sailitaly]

U can go close to 70mph. Yes, u should get 75miles @55mph with 10℅soc remaining.

Thanks 67BGTEV!

 

[Sailitaly]

Quick update on the Honda. I can't do the build in the garage at my house because there is "too much" going on in my garage at this point. I am planning on finding a garage to rent for the next few months but we'll see how it goes.

I want to get 100 Miles but here is my math so far.

75 miles X 300W/hr(Safe bet for the Honda)= 22,500 W/hrs or 22.5 kW/hrs

22,500W/hrs / 144V = 156.25 A/hrs

156.24A/hrs X 1.32(lithium) = 206.2368A/hrs

Looking at the Power graph of the motor it looks like it can handle it.



Am I on the right track or totally off?

How would I add 25 mile range to this? More batteries in Parallel?

I have read/heard if I keep the voltage of the Batteries at 3.2-3.5 and don't go higher I don't need a BMS. It's when you get above 3.7 volts when these Calbs start to "get quirky." Also bottom balancing is important.

I really want to figure out this math before I go buying a bunch of parts.

Thanks for everyone's help so far.

Here are the battery specs.
180 Amp-hours capacity - 576 Watt-hours.
3.2v nominal voltage
3C continuous current 540 amps
10C impulse current for up to 30 seconds 1800 amps
Charge to 3.60 volts and hold until current decreases to 9 amperes.
Discharge to 2.50 volts. -20 to 45 Centigrade
Cycle life over 3000 cycles to 80% Depth of Discharge

272x180x71 mm 10.70 x 7.08 x 2.77 inches
12.4 lbs - 5.6 kg


Justin

 

[dougingraham]

I have heard of people using 46 cells in series with the high voltage Curtis. So 46 180 AH cells = 26.5 kwh. If you get 300 wh/mile then the drop dead range should be 88 miles. If you went to 200 AH cells then your pack is 29.4 kwh and this would give you a drop dead range of 98 miles. If you could make 49 cells work that would give you the 100 miles. 49*3.2*200 = 31.4 kwh giving 105 miles of range.

I would go with the 48 cells of 200 AH or pairs of 100 AH. I am going to read back a bit and see if you told why you selected the AC-76. The motor is not what limits the power, it is the Curtis control. All the HPEVS motors put out about 88HP. The difference is the torque band. I dont see any reason to choose the AC-76 over one of the smaller frame motors unless you use an inverter that can accept a higher battery voltage. With a higher torque motor like the AC-76 you will find you have to shift at 3000 rpm because that is where the torque drops off. I would choose one of the motors where the torque drops off at more than 5k rpm. It will have less torque but the wider RPM band means you dont have to shift so soon and would make the lower gears useful. You might even find that first gear is useful if you find a motor where the torque drops off at 7k or more.

 

[dougingraham]

No mention of why you were thinking of the AC-76 but let me show why this might not be the best choice. I wish I could find the gearbox numbers for the 96 accord but they didnt want to just pop up with a google search. So I will use the ratios for my car as an example.

Overall Reduction
1st gear = 14.36
2nd gear = 8.67
3rd gear = 5.60
4th gear = 3.91
5th gear = 2.96

AC50 at 144 volts has a flat torque curve of 80 ft-lb up to about 5800 rpm.
AC76 at 144 volts has a flat torque curve of 150 ft-lb up to about 2900 rpm.

First number is AC-50 and second is AC-76
First gear torque = 1149/2154
2nd gear torque = 694/1301
3rd gear torque = 448/840
4th gear torque = 313/587
5th gear torque = 237/444

Many people have found that with a high torque electric motor that first gear is nearly useless. With my Warp9 at 277 ft-lb that is certainly true. But I found that when I limited my current to 500 motor amps (about 100 ft-lb) first gear was usable. If you look at the AC-76 numbers and compare to the AC-50 numbers for one gear less you notice that they are not too far apart. An example would be 1149 for the AC-50 in first to the 1301 for the AC-76 in 2nd. The big thing here is that because the torque remains flat out to twice the RPM with the AC-50 you end up with very nearly the same shift points. With the AC-50 shifting from 1st to 2nd on my car would take place at 28mph, 2nd to 3rd at 46 and 3rd to 4th at 72. If I had an AC-76 it would be 1st to 2nd at 14 mph, 2nd to 3rd at 23 mph, 3rd to 4th at 35 mph and 4th to 5th at 51 mph.

Around town with the AC-50 I would probably just leave it in 2nd all the time. With the AC-76 I would be shifting between 3rd and 4th all the time as my route has a couple of miles of 45mph speed limit.

The fact is that you don't get more total power with the AC-76 than with the AC-50 if you use the Curtis controller. The controller is the power limiter. The AC-76 costs more and weighs more. The torque band of the AC-76 is half that of the AC-50. The AC-76 really needs a controller with twice the voltage of the Curtis. If I was going with an AC system in my car today it would be the AC-50. It will be a better match with the existing transmission. Because your gearbox and final drive ratios are different your numbers will be different than mine. But not too different. It would pay to work the numbers for both motors.

I hope that helps.