openinverter forum

Time for a bit of a change. I've had my fun with the Valence green 20V packs, spent a lot of time with various balance chargers and bench chargers patching them up. The bad packs have gone to a guy in Cavan taking them apart and building a power wall with the good cells from them. All the good packs, fully top balanced and with BMS board added, have gone to a friend who already had a bunch from the original batch from the converted buses and wanted more for a massive home power wall

So the Red Arrow is without a battery. Apart from a 35S1P pack I built from cheap Chinese 32700 LiFePO4 cells that can get the car to the end of my estate and back, at a push

So, looking for a new battery. I feel any sort of PHEV pack will do the trick, although I need to end up with something between 120V and 240V. Less and the precharge circuit will prevent it from running. More and that would be too much of a push on the DC 48V motor. A BMW 530e / 740e pack would be ideal as it has 6 blocks, which I could split up in 3S2P

Staying true to the Red Arrow, a €1,000 EV, the battery needs to be cheap and can not be lead acid. Capacity not that important, even 6-7kWh is more than adequate

What have you? Any suggestions and offers welcome! Feel free to post here or PM me.

Maybe ask Marty what he has for good old (24kWh) Leaf modules? It's the "Various EV parts for sale" thread.. Price will depend on SOH, of course.

I was wondering what ever happened to the Red Arrow. Neat.

I dunno about putting 240vdc on a 48v motor. Everyone seems to max out around 150v, and that's with fairly advanced timing. Though I suppose it depends on what it's using for a controller and what it actually feeds to the motor.

Pre-charge circuit probably isn't a problem, I presume it's all of a resistor that you have to change to get that to act differently. But, yeah, you probably don't want less than 120v anyway.

Now, how true are we staying to the 1000eur build?

Naturally these are just silly rules for the challenge of it, and I think Damien bent the rules anyways (both ways, he included the cost of the vehicle in the conversion, which is bonkers). So, your car, do whatever you want.

The batteries were originally an Opel Ampera pack (Chevy Volt), but he cannibalized that for another project and left it with the Valence bats mid-build.

You're supposed to be able to reach 70mph, and have 40 mile range.

Damien originally paid 600eur for the Ampera pack, and said it wasn't a fluke because they offered him another one a few days later for 500eur. This probably isn't something you could pull off today like you could 4 years ago, but there you go.

To stay strictly true to the original build, you've got 600eur in your budget, to pick up 40 mile range at 70mph :p

I'm otherwise useless for european pricing and options. But best of luck.

Budget is not that strict Matt, I'd be happy to pay the going rate for a PHEV pack, target is about €100 / kWh. I don't need much range as it's a Dublin car for local trips, so the smaller the pack the better really. Also competing less with others. The 12kWh BMW PHEV packs are much higher sought after than the 9kWh packs i.e.

As for 240V, the Red Arrow left Damien with 10 * Valence 19.2V packs in series, so fully charged about 210V. At some point I tried 12 of these in series, over 240V, all good. That said, the Red Arrow is from '96 and has over 250k miles it, it's tired and old. So I drive it with mechanical / electrical sympathy

@Marc - thanks for the suggestion, but I am trying to avoid Leaf batteries as I find these are generally overpriced for what they are. I guess this is because they are popular. But I suppose I wouldn't rule out a really cheap and maybe badly degraded bunch of modules! Budget is the very reason I was looking for a PHEV pack as they tend to go under the radar, particularly the smaller ones. Until of course Damien spoiled this

Just saw this on eBay, might be a ferry trip away but it’s a great price,
https://www.ebay.co.uk/itm/234817601807 ... media=COPY

Cheers Ev8, that pack from a 330e is not suitable though. It has 5 internal packs in series, with total voltage too high for the Red Arrow. That's why I need a pack from a 530e / 740e which has 6 internal packs, which I can split up in 3S2P

Not sure who marked this thread as [SOLD], did I do that by accident myself? Could somebody please undo that?

Fairly sure that is a 6 module pack, wouldn't the 354V on the label make it a 96cell?

Yes that’s a 6module pack

Cheers guys, yes seems to be the newer pack with 354V * 34Ah = 12kWh, even says so on the label

16S * 3.7V * 6 packs = 354V

Good value then for what it is! Pre-brexit I've been to the UK to import cars several times, but the pack wouldn't be so cheap if I had to pay 10% import duty and 23% VAT over it if I went to collect it.

Also I think Damien was looking for one of these? We need to give the boss priority, his stuff is more important than mine.

Kilcock dismantlers have a BMW PHEV 9kWh pack if anyone is interested. They want €1500, not budging. Yeah, good luck with that.

Haven't much luck sourcing a BMW PHEV pack in Ireland. And no time to go pick one up from the UK. The DIY EV meetup is on in a bit over 3 weeks, I would like to bring the Red Arrow. Also the car is booked in for the NCT that week too.

Any help appreciated, anyone know of some cells / a pack for sale? Maybe I could borrow a battery for a few days?

Anything from about 120V to about 240V and from about 5kWh would do the trick for pottering around locally!

As per my other listing I have a few different modules available, perhaps 5 of the GTE modules could work? Would give roughly 5kwh, can do £90 each + shipping if that’s of interest

We can try to trade for six LEV40-8 modules with 27 to 28Ah of juice left in them, about 5kWh. Currently in use as 4P12S 48V boating battery but easy to revert back to 1P8S modules. Pick up in Amsterdam, trade for openinverter, simpbms (teensy3.2) electronics, other interesting things to add to my testbench or €50,- per module without bmu.

Thanks for the offers, lads. I got lucky this morning and did a deal on a 530e 9kWh pack. Thanks a million to paaa for making this happen!

Well done! Did you manage to stay within the red arrow budget?

addvalue wrote: ↑Tue Jan 31, 2023 5:18 pm Well done! Did you manage to stay within the red arrow budget?

No but there is no point massively constraining the cars limit for the sake of a small amount of money. I would doubt anyone would argue if you increased limit to 1500 or 2000 but vastly improved the car.