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My car charger got here quicker than I expected. I'm only 10 cells in to charging the pack with individual cell chargers.

Opinions? Assemble the pack and let the on-board BMS do its thing or continue topping off the cells individually for the next month?

Also - anybody read Chinese?




Might be risky depending on how different the state of charge/voltage is between cells is.

Here's the translations a Chinese to English dictionary provided (very handy website, lets you draw the characters: http://ce.linedict.com/#/cnen/home ):

1: Assuming this means wall power connected:


2: Assuming this means car connected:


3: Currently charging:


4: Error:
 

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Discussion Starter · #22 · (Edited)
Here's the translations a Chinese to English dictionary provided (very handy website, lets you draw the characters: http://ce.linedict.com/#/cnen/home ):
Thank you. I've been looking for a good one since nciku.com shut down. The few I've found suuuuuuuuck. This one works as well as nciku did. Looks like it might even be the same engine under the hood.

Harmon
 

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Discussion Starter · #24 ·
The car specs say they're LFP batts and I have no reason to suspect otherwise. My understanding is that 3.6V is the standard. They will charge past that but it kills them. The chargers I bought do hold the voltage at 3.6v while the amperage drops off and they shut off at 3.6v @ 0A.
 

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Discussion Starter · #25 ·
Ooooo, I'm excited. I just found a pdf from the Shanghai Science and Technology Information Institute in 2015 and an industry report from the same time that claims my donor car had a range of 160km.

The Beetle has a curb weight of 1850lbs and swapping ICE & fuel tank for LFP batts and motor should be a wash, or pretty close to it. The JAC has a curb weight of 2600lbs. So I'm shedding about 800lbs or 30% as far as the JAC drive is concerned. I'm thinking 100mi range isn't out of the question, yes?

That's way better than I was expecting. I'm excited. Charging these cells is taking way too long. It's killing me. I'm ready to get this project under way.

Harmon
 

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Discussion Starter · #27 ·
I keep going back and forth on the single speed vs shifting question for the Beetle.

Part of me says I should take advantage of the fact I have multiple gears to select from to keep the motor where I want it for any given situation - high torque, high speed, low current, whatever.

Another part of me says I shouldn't try to re-invent the wheel and the JAC manufacturers have the motor mated to a single speed gearbox for a reason. Find the total ratio in the JAC and pin the Beetle trans in the closest gear.

The first part then points out that the reason is cost (money & weight) and simplicity. They'd go multi-speed if it weren't for the fact the cost:benefit analysis wasn't in favor of it and a typical user wouldn't be savvy enough to know what gear to select in an EV application. So since the Beetle already has multi-speed and I [sorta] know what to do with it then I should take advantage.

Then the second part calls the first part an idiot, the permanent magnet synchronous motor has an inverter and control system that knows how to and can deliver what is asked of it with the throttle so quit thinking you know more than the engineers.

Anyone want to referee these two before it comes to fisticuffs?

Harmon
 

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Hi Harmon

My take on the single speed multi speed situation

I did the numbers and I realized that I could break traction in top gear - that means that going to a lower gear has no benefit
 

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Discussion Starter · #30 ·
I think I'm going to go clutchless and just pin the trans in 2nd or 3rd.

I just pulled the last cell off the charger this morning. The donor will be reassembled and tested this weekend. I'm excited!

Harmon
 

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Discussion Starter · #31 ·
I finally got the batteries all topped off and I thought for sure I'd get the JAC pack put back together and tested this past long holiday weekend. I was too optimistic. I only got a couple hours a day to work on it and it is going together much slower than it came apart, much much slower than I'd anticipated. A lot of fiddly bits and wires to mess with and I find myself spending more time than I probably need to buffing conductive surfaces to get them nice and shiny. A patina on the copper tabs is probably the least of my worries in this pack but the little man inside me says I have to do it. My little man's an idiot.

Harmon
 

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Discussion Starter · #33 ·
Well, a mixed bag today. Finally got a whole day with enough daylight and temps in the high 30s so I could get out and work on the JAC's battery pack. Winter sucks. Get up and go to work in the dark, come home at the end of the day in the dark.

I got it all back together, optimistically vacuumed all the glass off the dash in anticipation of massive winds coming over the front of the car as I blasted down the road, plopped a step stool down where the drivers seat was supposed to go, and floored it....nothing.

Meh. I knew it was too much to hope for but I played like I really thought it was going to happen in case it did. The climax to all the anticipation during the day as it came together would have been great.

The charger I bought from Aliexpress didn't seem to even acknowledge the car at all.

Nothing really changed about the behavior of the car. I seemed like it wanted to work but thought the battery pack was dead.

The accessory battery is only putting out 8v and the whole system died fairly quickly. Going to charge it up and see if it makes any difference. Probably not, but I'm going to hope anyway.

I said I'd write this whole thing off if it didn't drive and not sink any money into it, but I can't help it. It's trying so I don't want to give up yet. So the troubleshooting begins.

Harmon
 
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