[Ace_bridger]

[Ace_bridger]

[Ace_bridger]

I've bought an EV200 contactor to switch the high voltage and plan on switching the EV200 from the 'ignition'. I also plan to run an emergency shut-off (big red button) in series with the 'ignition' switch wire so that I can simply hit the Big Red if something fails and I need to cut the supply. The Big red will be in the cab within reach of both driver and passanger.

For wire I'm going to go big, probably too big but hey. I plan on using a 144V/500A controller from Paul & Sabrina so I'll spec the battery circuit wire and the motor circuit wire for 500A. The battery pack will be 60Ah to begin with and the Sinopoly cells are rated at 3C continuous and 5C for up to 10secs so I plan to drive keeping under 300A.

I plan to fuse the battery circuit and the motor circuit but am not yet decided upon which kind of fuse to use or the rating. I'm thinking 400A. Either a


Enlarge

Ferraz Shawmut

or a Little Fuse as they're somewhat less expensive.

[mora]

Cool. So you decided to get Sinopoly cells. I'll be watching with interest. My 96V -> 144V upgrade is almost complete.

Your golf looks prettier than mine, hehehe.

Regarding fuses: get ones that are rated for DC. I'm not sure if even 415V AC rating is enough for breaking DC. I got mine from discountfuse.com even they don't ship outside of USA. There are cheap mail forwarding services to take care of that problem, hehe. I just couldn't locate any fuses at acceptable prices inside EU.

[Salty9]

Ace,

Be sure to get info about emergency disconnects. DTBaker has some good info in http://www.diyelectriccar.com/forums...ngs-57522.html

[Ace_bridger]

Hey Mora,

Well, there is a story about the Sinopoly cells. I had decided against lithium based on initial cost and was going to buy them later once we'd moved house and had baby number two, who is due in May. I'd had a quote from a guy on here (Skooler) initially and he generously lowered his asking price to help me out!! I couldn't say no so hopefully I'll order 45 60Ah cells this week and they can be put on a slow boat from China.

I did the full weight comparison of lead Vs lithium and that weight saving alone should extend my range significantly. The extra voltage will help me out on range and will hopefully extend the life of the Sinopoly cells too.

I hope to add another 60Ah at a later date.

Are you running BMS? I wasn't going to bother as I will keep a close eye on them and monitor voltages etc. In truth I don't really fully understand what the BMS does other than communicate with a charger to ensure that no cell in the pack gets over charged. Advice welcomed.

About my Golf being prettier than yours; your car is my inspiration and if I can get close the professionalism and comprehensiveness of your conversion then I'll be a happy chappy.

I am fortunate that the previous owner did a full bodywork and respray about 18 months ago. I love the car and it's not even moving yet!!!

More pics and updates as the car develops.

[Ace_bridger]

I was planning on putting an interia switch in there too in case of heavy impact.

I'm in internal debate as to whether to have the 'ignition switch, emergency Big Red Button and the interia switch all in series in the main contactor swicth wire or whether to have seperate EV200 contactors to cater for it failing closed. Opinions welcome.

I don't really want 144V in the cab of the car but might put an Anderson connector in the trunck and one under the hood. Might prove useful during maintenance too.

[mora]

I use miniBMS. It will alert you if any cell goes too low on voltage during drive and will terminate charge if any cell goes too high during charging. It is very simple, easy to install and propably one of the cheapest too. Some say BMS isn't necessary but I wouldn't go without it. You should monitor your cells somehow in any case. Ah-counter and total pack voltage monitoring isn't enough in my opinion.

[Ace_bridger]

Thanks Mora,

I plan to monitor closely by hand to begin with and then perhaps I'll get a BMS and miniBMS certainly looks good value for it's functionality.

A question for you: what is your current draw like under normal driving?

Thanks for the fuse link. I think I'll fuse the battery circuit and the motor circuit...unless the controller already offers suitable protection already.

Maybe when the Golf is ready we should meet up at the Nurburgring . I wonder what the lap times would be .

[mora]

Hehehe. Could we make two full laps if taking it slow?

When going on flat road: ~125A to maintain 80 km/h, 175A to 100 km/h. In city I rarely exceed 200A during acceleration and can cruise using 50A when going 50km/h. Less than that means even less amps. I use second gear all the time. If going faster than 60 km/h I put in third gear. I have to use 4th gear to get to 100 km/h. 96V is too low for my 220V Kostov and torque drops early. 144V should be good though. Actually I'm upgrading because of heater but any extra top speed/lower amps is good too. I think I'll downsize my cables a bit and put them into orange wiring conduit. 70mm^2 (2/0?) is needed only for motor loop, other battery cable can be 50mm^2 or even 35mm^2 for my needs.