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I don't know much about it myself to be honest, other than to say that three 7 kW on-board chargers and a Type-2 inlet would make more sense. If you have room for them of course.

SEI is both necessary to protect the anode, and unfortunate as it depletes the lithium inventory. Crud has to come from somewhere, and the mobile Li+ ions are a good source. So gains in the SEI means losses in mobile ion stock. Net result is lower useable capacity and higher internal resistance. If ...

Ooooh, any plans for the next vehicle? Budgets?

Work out what the DCIR of the cells are first.
0.5 V / 200 A = 2.5 mOhms. Not bad.

So if you had a nominal 96 of them in series for a typical 355 V system, your total DCIR might be 0.24 ohms.
200 amps at a nominal 355 V is 71 kW, but I^2 x R losses mean you're generating 10 kW of heat!

Finally, about 5 weeks after starting, I have spot-welded the last tab to the busbars. Last thing to do now is solder the 6 or 7 recalcitrant tabs which can't be welded. You can see them where I've ground back the passivated nickel surface. Then do the cell top welding (about 2 hours there) before p...

These are the ones I was thinking of. Plus the one @4Springs put together here on the forum.

ZEVA - https://www.zeva.com.au/
EV-Power - https://www.ev-power.com.au/webstore/

There are cheaper BMS's around, they just have less fruit. If fruit is your thing Batrium has it by the ... bowl full.

Oooh cheap Korean home storage batteries coming to a garage near you!

You mean use the Leaf battery as is? If you can use the CAN protocol to operate the BMS, then I can't see why not. You'd need a high voltage DC hybrid inverter though. It's much easier to pull the battery apart, sort the laggards from the good cells, re-configure as a 14s pack and buy a 48 volt hybr...

Volta wrote: ↑Tue, 09 Feb 2021, 22:11 Thanks for all the info. gents. Series is the next step. As for the comment by Mr Jones are you alluding to the fact I may be over the hill?

Tongue firmly in cheek. I'm sure you have a strong right foot.

Depending on your battery voltage you might not have the top speed you want, but I'm sure you're past all that now eh Dave?

Ah yes true there is that approach for sure. I see a guy on Endless Sphere has bought a pulse arc welder for welding 0.4 mm thick copper to cells directly. Does a good job, and 0.4 mm thick copper is about equal in conductivity to 1 mm aluminium, with none of the intermediate resistance of a nickel ...

Thanks, I just finished module #2. We had the remains of a tropical low come south to visit Perth, so while the cooler weather is very welcome, the humidity isn't quite so popular. I'm watching the busbars of the remaining two modules start to get progressively more and more passivated. Some of them...

thermal epoxy going on.jpg A shot of the thermal epoxy before the FR4 goes on. I have had to contend with some passivated sections of busbar which will not take a spot weld. I can't even solder it. But as they might only impact half a dozen cells per busplate, I can't really justify making a new on...

It's bollocks. Two years overdue and full of nothing. Literally seeks to just do nothing and let the market sort it out. Actively promotes 20 year old technology (hybrids) as new technology and lies about their supposed advantages. Taylors comments today were littered with contradictions. "We see no...

I used copper busbars wherever possible, and 50 mm2 cable and lugs. But I'm running higher voltages so the currents are much closer to 150-200 A.

All I know is it used a nickel sulfamate solution, so electrolysis was involved I think.

Oh there may well be one, but I was fast running out of time (still am). Plus I have no experience with nickel plated copper and how it welds.

Copper is highly reflective, so it needs to be a fibre laser so the optics don't get burned out. They can't cut nickel for this reason either. Waterjet cutting has a kerf of about 0.5 mm which is probably OK for this stuff, but the sheer number of holes and cuts made it expensive and slow. I'd block...

top side welded.jpg Module glued up.jpg Okay, so the first module is more or less done. Some key observations about this battery building technique. 1. It's painfully slow, but only because I have a small welder with tiny electrodes. I feel it would be faster if I only needed to zap each tab once o...

There's a lot of learning as I go along too. I finished the other side of this module in a day, but yeah its a huge job. If the nickel stuck to the plated aluminium like I want it to I could have done all 4 by now.
In future I'll use 21700 cells, as they're 30% less work.

Dave I tried paralleled DC motors on my first electric motorbike and it was a PITA. One motor would always end up doing the work. It's far better if you put them in series and let them share current equally, even if that means more volts on the battery pack.

Well this latest community transmission detection has resulted in a week of not going to work, which means a week of no pay. At least that means I can work on the battery modules in a hot shed all day. first module bottom side welded sml.jpg I've finished spot welding one entire side of a single mod...

Yeah, but I'm trying to get the car out of the garage by the end of February. No good ordering stuff now given Chinese New Year. I worked out I can do a busplate (46 tabs) in 40 mins. So that's 8 days work of 8 hours a day. With four welders and four people, I should be able to knock that down to ab...

And Bridgetown is a good little town for EVs per capita. I know of about three or four in the area!