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Sir Forkenswift · 14 February 07

Darin sends tidings from the land of Forkenswift.

Battery Mockups pot box installed

FYI, a pic: showing the potbox installed on the firewall, throttle cable connected. And we’ve been playing around with battery mockups for placement purposes. Probably 4 up front, 4 in the hatchback for a 48v system.

We picked up 8 free 6v floodies from the forklift company that sold us the decommissioned lift truck. They came out of floor cleaners, replaced on a service schedule. 7 of them even appeared to take a full charge (though they haven’t been load tested in any meaningful way as of yet).

The only thing standing between piling 6 of the batteries on the floor and going for a spin around the block is … winter! Kind of saps the enthusiasm for tinkering, doesn’t it?

Thanks Darin. Here’s some past links, should you be just joining us (forkentheroad?).

Comments 19
  1. — James May    Feb 15, 2007 08:41 AM    #

    Hi, I think Darin should not try to use the faulty 6V battery, better to ask the forklift place to earmark another one of a similar age and go and collect it sometime. I hear that dying batteries can sometimes be fixed with weeks of trickle charge but I am yet to be convinced of this, it didn’t work for me.

  2. darin    Feb 15, 2007 13:18 PM    #

    Hi James –

    I’ve already asked :D. If the battery won’t come up to charge except with undue fiddling, we’ll omit it from the mix.

    I’m eager to find out if these batteries have any useful juice left in them. If they do, I can think of several other projects that would be happy to have free old floodies.

    The Arctic influence should start to diminish in another week or 2, at which point the possibility of a road & load test increases…

  3. matt    Feb 15, 2007 14:27 PM    #


    just wanted to say that you’re my hero. (you and yugo-greg of course) hopefully it warms up in southern and eastern ontario soon!! (my ICE car produces no heat…)

  4. darin    Feb 16, 2007 11:39 AM    #

    Hi Matt –
    Does that mean Greg’s responsible for TWO EVs now? No pressure, Greg!

    I read your web page – and the challenge you face (terrain). It’s more or less flat here, and I can drive around some of the hills for an alternate route. Good luck & keep us posted.

  5. Gavin Shoebridge    Apr 04, 2007 03:28 AM    #

    Well done Darin mate!

    I saw the video on youtube of Forkenswift doing a test run. Very very impressive.
    I liked the use of many different camera/audio angles and that guy shouting “Hey why’s your car so quiet?” must have made your year!

    Good stuff! That video gave me a solid jab of motivation!

    Looking forward to the rest of the progress.


  6. darin    Apr 04, 2007 21:18 PM    #

    Thanks, Gav. I couldn’t have staged it any better if I’d tried!

    Enjoyed your vid too and have checked out your site. Nice work.

    There’s nothing like watching other people’s projects to get the juices flowing, eh?

    That’s what I love about this site – Jerry takes in all us “EV strays” and we’re all better off because of it :D).

    – Darin
  7. darin    Sep 11, 2007 22:23 PM    #

    Wow – time flies. Here’s a brief ForkenSwift update, in case you think I’d forgotten:

    - This summer we were given a batch of used batteries from an EV Ranger pick-up owner in Ottawa. They’re 3 years old, and he was ready to recycle them, but they’re far better than the batteries we were getting from the forklift company – reasonably well balanced, and perfect for a first pack (which we will surely murder).

    - the front & rear battery racks are made (I’m learning to weld!) & all batteries are securely mounted (much better than piled on the floorboards)

    - currently we’re working on sorting out the cabling (using some donated, used 3/0 find strand welding cable), and mounting hardware in the motor compartment (controller, contactors, etc.)

    Within a few weeks, I expect we’ll have the car in for its final inspection. If all goes well, we should be able to start driving it – legally – this fall. (Though I’ve already put about 150 EV kms on it.)

  8. jerry Halstead    Sep 12, 2007 05:29 AM    #

    Great news Darin!

  9. — James May    Sep 12, 2007 07:00 AM    #

    Hi Darin

    Crimp, don’t solder. Clean those battery posts. Tighten everything carefully.


  10. jerry Halstead    Sep 12, 2007 07:05 AM    #

    …says the voice of battery-terminal-meltdown experience!

  11. darin    Sep 12, 2007 08:46 AM    #

    James, I have actually been checking (touching) every connection after almost every drive. That photo of your melted post has been a good motivator!

    The only hot connection I ever encountered was when I was still using an old, ratty 12v starter-battery cable from a junked car between 2 batts. (Now there’s 3/0 cable throughout.)

    On the issue of crimp vs. solder for the lugs… I have actually made ends on half a dozen cables so far, and they seem to be working fine.

    I flattened, fluxed & heated the end of the cable, then dipped it in molten solder. Then (when cool, obviously) carefully ground/filed the resulting surfaces level.

    A few pictures of this, FYI:


  12. — James May    Sep 12, 2007 13:55 PM    #

    OK Darin, y

    I see you are taking care, I’ll get off your back.
    I hadn’t cleaned the post at all on my meltdown Trojan and it had a thin layer of lead oxide on it. It wasn’t shiny. That’s why it happened to me. These terminals do seem to loosen on their own after a while. I haven’t figured out why, perhaps it’s creep in the lead. The solder lugs look OK. Remember that the bulk conductivity of 60/ 40 solder is very much lower than copper, and I think it will be lower than the lead alloy of the terminals as well.

    Also 60 / 40 Solder melts at a very low temperature so if you do have any problem, it might lead to catastrophe.

    The lead free (mostly copper) solder melts at a higher temperature, I think it is above 200C Probably has better conductivity than 60/40 solder as well.

  13. Gavin Shoebridge    Sep 12, 2007 23:37 PM    #

    This is a bit off topic but does anyone know if a circuit breaker designed for AC voltage would work in a DC car.

    The specs are:
    500V AC Rated
    200 Amp trip
    “interup. cap. sym.” of 18kA at 240V AC

    Not sure what that last bit means.
    You can view a picture of it here:

  14. darin    Sep 13, 2007 01:50 AM    #

    James – I’m happy to report I used the lead-free type of solder. (But I’m not going to pretend I did it on purpose knowing its conductivity relative to lead – though I was aware it had a higher melting temp.)

    Thanks for the info.

    Gavin – not sure about the breaker… I’m actually pondering what kind of mechanical emergency disconnect we’ll use. I know some people use breakers with a cable pull into the cabin.

  15. Gavin Shoebridge    Sep 13, 2007 02:50 AM    #

    It’s alright Darin, I’ve been advised “NO!” in another forum regarding that AC circuit breaker.
    DC and AC contacting stuff is radically different and shouldn’t be inter-changed!
    Lesson learned for me!

  16. — James May    Sep 13, 2007 08:41 AM    #

    I have proof about the lead free solder.

    It says:
    Electrical Conductivity 16.6 %IACS 11.9 %IACS

    which means perecentage conductivity of pure copper for lead free solder and normal eutectic lead tin solder. As you can see, the lead free is nearly 50% higher

  17. Gavin Shoebridge    Sep 14, 2007 07:25 AM    #

    Hey Darin, EVUSA have good prices on circuit breakers.
    I just bought mine today from them for $52.50 US which is a steal!

    Stuff like this is 4 times the price (if you can find them) in NZ.

    If you’re curious then here’s the link!

  18. — jim hurst    Sep 14, 2007 21:53 PM    #

    They dont seem to have a 450 amp circuit breaker. It would not take long to pay for itself, fuses are expensive.

  19. Gavin Shoebridge    Sep 14, 2007 23:00 PM    #

    I’ve read of other EV’ers using that same 250A circuit breaker up to 800A briefly without tripping so I’m not too worried about that. It’s only there as an emergency cut-off so it’ll be fine for most EV’s.
    Don’t worry Jim, I researched and checked before handing over my cash!