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Discussion Starter · #1 · (Edited)
Hello all, I am hoping to compare the range of my S-10 with close or similar EV build.

Truck info:

'92 S-10. 6' bed, 5 speed trans.
Curtis 1231 controller
ADC FB1-4001 motor
54 Leaf modules (Gen 1 Leaf) in an 18S 3P config
Max charge 147.6 V (8.2V per leaf module) pgm'd into charger
Min charge 90 V (5V per leaf module, online spec)
Amp hours, 192Ah on paper

I bought the truck in Dec '18 and just completed a battery upgrade from lead to Leaf modules. I wired them in 18S 3P config which should net me 28KW (on paper) if I'm doing the math correctly.

I recently took it out for a range test. Northern VA so some hills are present, nothing over 5% grade for the test and all city driving up to 45 mph. I started with 100% battery at 147.6 V and stopped at 116 V. Not sure but I think I used approx. 80% of the battery. My total range for this test was 50 miles. My driving style was casual and not aggressive. Only me in the vehicle and not hauling anything.

Whew, hopefully enough info. Let me know if you need more. My question is, does this sound correct? The 50 miles for 80% usage? I do know that Leaf modules are prone to losing capacity and I expect there to be some loss since I bought these used not knowing the exact capacity. Pics show front and rear batt boxes, and control board.
 

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My question is, does this sound correct?
Ballpark, yeah.

147v peak is presumed at 4.1v per cell. Nominal is 3.7v, so, nominal of your pack is 133v.


133v * 192 AH = 25,500 watt-hours. (They might call this a 29kwh pack, because apparently everyone uses peak voltage not nominal).

You discharged to 116v. Which is 3.2v per cell.

You drove about 45mph and covered about 50 miles, so, about 1 hour of driving and didn't drive them dead, so, a little under 1C of discharge.



At 3.2v per cell you're closer to 90% of your pack capacity, not 80% like you hoped.

So, your 25,500 watt-hours you used 90% of, so, 23,000 watt-hours. And you covered 50 miles. That's 459 watt-hours per mile.

That seems... ballpark correct, maybe high considering you weren't going 60mph. At 45mph, you should be closer to like, 250 watt-hours per mile using the usual calculator for those truck specs. If those were new batteries. Gen1 Leafs are known to be crappy.

City driving makes that take a hit. You lose every start and stop. Hills too.

You're in luck though, here's someone's consumption analysis of an electric S10: http://www.evamerica.com/0evcalculation120vs1012410.pdf

I'd say you're using more power than I would otherwise think you would be using, but considering old batteries, city starts and stops, and hills, there's nothing wrong with your setup. You're getting about what you should be getting.
 

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Discussion Starter · #3 ·
Thanks for the info. I could tell I was nearing the end of the pack as I was starting to get the lithium power drop off at 116V. I'm ok with 50 miles for now. The "bones" are now in the truck so I only have to add batteries to get more range.

I also think the wider tires/wheels may have stolen a little distance. I usually always go for function first before looks and the wider tires/wheels were the only non-function item I installed. I really didn't like the look of the tiny donut sized 14" wheels that were on the truck previously.

Anyway, thanks again. Going to perform another range test when I get back from Florida this coming weekend.
 

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(They might call this a 29kwh pack, because apparently everyone uses peak voltage not nominal).
But no, "everyone" doesn't do that; no responsible EV manufacturer does that. The original leaf cells are about 33 Ah capacity, in a 96S 2P configuration; with 3.75 V/cell nominally (which if I recall correctly is what Nissan assumes, despite the appearance of the SoC curve), that's 24 kWh... just as Nissan has always claimed.

There is a difference between nominal capacity (what you get by multiplying nominal voltage by capacity) which is determined based on 100% and 0% SoC, and the smaller "usable" capacity, which is determined based on the more conservative SoC range which the BMS actually allows to be used.

In this test, the usable capacity is determined by the range of 147.6 V (100%) to 116 V (thought to be 20%). If SoC versus voltage curves with straight (which they're not) and the cell capacity were 33 Ah (which they probably are not any more), that would be 26 kWh; it's probably less.

The nominal capacity of 54 modules from Leaf packs that were nominally 24 kWh for 48 modules would simply be 24 kWh * 54/48 = 27 kWh
 

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...
So, your 25,500 watt-hours you used 90% of, so, 23,000 watt-hours. And you covered 50 miles. That's 459 watt-hours per mile.

That seems... ballpark correct, maybe high considering you weren't going 60mph. At 45mph, you should be closer to like, 250 watt-hours per mile using the usual calculator for those truck specs. If those were new batteries. Gen1 Leafs are known to be crappy.

City driving makes that take a hit. You lose every start and stop. Hills too.

...

I'd say you're using more power than I would otherwise think you would be using, but considering old batteries, city starts and stops, and hills, there's nothing wrong with your setup. You're getting about what you should be getting.
I agree with all of that, although 250 watt-hours per mile for an S-10 seems unreasonably optimistic. I'll also note that urban driving with hills and no regenerative braking is a bad combination.
 

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I also think the wider tires/wheels may have stolen a little distance. I usually always go for function first before looks and the wider tires/wheels were the only non-function item I installed. I really didn't like the look of the tiny donut sized 14" wheels that were on the truck previously.
Larger-diameter wheels don't necessarily mean wider tires. It would take some searching, but you may be able to find a 16" tire size that is not so wide. Width hurts drag, but diameter doesn't and both larger overall diameter and lower aspect ratio generally reduce drag.
 

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There doesn't appear to be any battery management system in this vehicle (just a voltmeter for overall pack voltage), since there are no BMS tap wires on the module terminals. Is that correct?
 

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There doesn't appear to be any battery management system in this vehicle (just a voltmeter for overall pack voltage), since there are no BMS tap wires on the module terminals. Is that correct?
Sure looks that way.

Also I notice that the center (BMS taps) are not wired up in parallel. This means that the cells inside your 7 parallel modules could theoretically get out of balance over time.
 

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Also I notice that the center (BMS taps) are not wired up in parallel. This means that the cells inside your 7 parallel modules could theoretically get out of balance over time.
Good point. Even without BMS, the BMS tap terminals should be tied (between the three modules in parallel), so that the pack is paralleled at the lowest cell level.
 

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Hi, sounds about right. I converted my Hilux last year using 60 Leaf battery modules.
I get a reliable 70km of range, as long as I pootle along at 80km/hr or less. This includes some hills.

 

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Discussion Starter · #13 ·
Sooo, after a couple range tests using the same route, speeds, weight etc. I decided to get some more data. I think the battery pack has less kw capacity than I initially calculated. Running numbers is great but it's not until you get the rubber to the road that you actually see what's going on. After one of my range tests, I connected my computer to my TSM-2500 charger can bus setup and recharged the pack. The software will show me how many kilowatts are charged back into the pack during a charging session. Having this data and knowing that I discharged the pack down to 90% I hoped to get closer to how much battery capacity I actually have.

I had used 15,601 watts to go 50 miles. If I'm doing the math correctly, I think that's approx. 312 watts per mile. Along with that, 15,601 watts is approx. 90% of my battery pack capacity which tells me I have roughly a 17,000 watt, (17 kw) pack or less. This makes more sense as to why I'm only going 50 miles on a charge. You guys/gals that are better at the math please chime in here especially if I did the math wrong. I'm bad at it. lol.

With that info, I'm currently in the process of doubling the total amp hours of my pack so that I'll get closer to 100 miles per charge. The current setup was built for a weekend use truck to run errands. On average I'll drive it approx. 50 miles on a weekend and I start paying close attention when I hit 35 miles. With 100 miles of range, I won't have to pay as much attention.
 

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Discussion Starter · #14 ·
Sure looks that way.

Also I notice that the center (BMS taps) are not wired up in parallel. This means that the cells inside your 7 parallel modules could theoretically get out of balance over time.
Correct, bms not installed yet. I built it in it's current config and started testing immediately. I plan to double the capacity of the pack and will add in the bms at that point.
 

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Ballpark, yeah.

147v peak is presumed at 4.1v per cell. Nominal is 3.7v, so, nominal of your pack is 133v.


133v * 192 AH = 25,500 watt-hours. (They might call this a 29kwh pack, because apparently everyone uses peak voltage not nominal).

You discharged to 116v. Which is 3.2v per cell.

You drove about 45mph and covered about 50 miles, so, about 1 hour of driving and didn't drive them dead, so, a little under 1C of discharge.



At 3.2v per cell you're closer to 90% of your pack capacity, not 80% like you hoped.

So, your 25,500 watt-hours you used 90% of, so, 23,000 watt-hours. And you covered 50 miles. That's 459 watt-hours per mile.

That seems... ballpark correct, maybe high considering you weren't going 60mph. At 45mph, you should be closer to like, 250 watt-hours per mile using the usual calculator for those truck specs. If those were new batteries. Gen1 Leafs are known to be crappy.

City driving makes that take a hit. You lose every start and stop. Hills too.

You're in luck though, here's someone's consumption analysis of an electric S10: http://www.evamerica.com/0evcalculation120vs1012410.pdf

I'd say you're using more power than I would otherwise think you would be using, but considering old batteries, city starts and stops, and hills, there's nothing wrong with your setup. You're getting about what you should be getting.
Hey sorry to but in here but I am elbows deep in a 2002 2wd oily s10 build currently and happily throwing away a bunch of the uneeded and wanted coincidentally also the leakiest of the oily parts out and acquiring buying electric parts as I can afford to swap in. Sounds like you guys might be able to give me a hint as to the amount of KWh I should be planning on buying/installing in my build. Them being the largest portion of investment in the project it would be helpful to know so actually sit down a do a real budget plan and help me kick the project into high gear. me my average miles driven a day is vary low 15. with min 8hr or so between half of that I could charge. But I do 2 to 3 nights a week drive to my sons 25 miles away. Half freeway 65 and other half 45 mph avg in town drive, and all in a old guy just retired no place he needs to be Sunday afternoon going for a rides pace. My son races late model stock cars he’s the driver I am the wrench. My brain says a 65 miles of range should be good starting point, then again I have 0 EV experience only oilyV and a strong desire to change that. Any tips suggestions knowledge would help and be greatly appreciated thanks.
 

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Discussion Starter · #16 ·
My truck has an approx. 17KW pack. I get a solid 50 miles at 45 mph or less. I built my truck to run errands on the weekends for speeds around 45 mph and the 50 mile range is adequate for now. The fastest I've gotten to so far is 55 mph and I could only hold it for approx. 2 miles. It pulls a lot of amps at that speed. There isn't enuf "balls" in my battery pack. For more range and just a little more speed, I'm in the process of doubling my battery pack size.

I'm going to break these down into the two trips you described: 15 mile and 25 mile. I'm basing this data on the truck I own now.

15 mile trip: My truck would do this trip at 45 mph with no problem in fact it could be done 3 times before charging. (Using no heat and 45 mph or under).
25 mile trip (1/2 at 45mph): My truck would do 12.5 miles at 45 mph with no problem. My truck would do the whole 25 mile trip at 45mph no problem.
25 mile trip (1/2 at 65mph): My truck can't do this. My guess is I'd have to at least double my pack to maintain 65mph for 12.5 miles.

Jay also has Leaf modules in his truck which is also similar to yours and may have different data.
 
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