[gdirwin]

I've been driving the EV for about 8 months now - no regrets, still have the grin!

Zilla was complaining about some hot temps (has not been a problem when it was -40!), so replaced the fan-driven 4" radiator with a 7"x12" aluminum transmission cooler - no fan, but I mounted it directly in the airflow behind the front bumper..

Also replaced a noisy strut-mount (nice and solid now).

Will replace my noisy vacuum brake pump today - using the VW/Audi pump now. I have been finding the reservoir does not hold as long as it used to - originally I got 3 pumps before the vac switch turned on, now only 2. I will look for loose fittings at the same time.

MY updated Zilla has been working well - no errors and better acceleration (originally I would get an error if I floored it - this was solved by limiting the throttle in the hairball firmware upgrade - now the power unit has been upgraded too, so back to full power).

I also got the BMS updated - the DC/DC converter was blown (likely my fault due to bad wiring - those darn tiny connectors on the BMS are a pain!). Elithion updated the firmware at the same time. My fuel gauge now works - the BMS outputs a 0-5V signal for SOC - I have a transistor circuit (from Elithion site) which drives the analog fuel gauge - only problem is that my Toyota has 2 resistive fuel level sensors (most only have 1) so my gauge shows 50% when it is full - I will have to play with the resistor values in the transistor circuit to figure this out.

In the old BMS version, any sag would result in SOC resetting to 20% - this seems fixed now, although there is less sag now that it is warm out (the real test will be next January). My charge current sensor is still not working, so I have to pull out the box with all the contactors etc.. to check it out.

[DIYguy]

You have an exemplary build there Garth. I really like what your have done and the choices you made for this practical vehicle. Tell me, how are the heated battery boxes doing? Do you monitor temperature at all? and do you ventilate in the summer (assume enclosed boxes).

Cheers,
Gary

[gdirwin]

Thanks Gary - the Farnam heating pads work great - all winter they kept the temps nice and cozy... I put them on a timer, so they came on a few hours before driving. I have some simple 120VAC thermal cut-outs, but never got around to using them. The boxes ended up with no insulation at all (not enough room) - with the heating pads it worked well though. I did not push high mileage though, and kept everything fully charged (mostly shorter drives) so not the best winter test.

There are fans in each bat box, tied into the Elithion bms (which measures the temps based on each cell board) - they have never come on yet (although this will be my first hot summer, so will see). They just vent into the car interior (I may have to change this).

I add a 240V/50A GFI box in my garage, so can now fully utilize my Manzanita 40A charger (before this I was only using 120/15A) - with the fast charger it always seems to be full whenever I go for a drive - should help the battery life. That said, on warmer days, I have to open the back door to keep the temps down inside the car - the charger throws a lot of heat.


Installed the VW pump - much quieter compared to the oil-filled muffler one I replaced. It is barely audible (compared to a incredibly loud HONKKKKK from the old one)... It is a higher pitch and runs for longer (much smaller pump) but all good. One note - the vent for the unit is a small hole at a joint (about the middle of the pump) - I thought it was the button on the bottom. I wrapped it with some insulation and duct tape (and covered this hole) and it kept running (ie did not produce any vacuum) - cleared the hole and all is well - most pleased.


Went for a 80 kM ride tonight (avg 80km/hr)- still had lots of juice left, no heating issues - all good.

[gdirwin]

I did a bit of repair work this weekend - I have been driving my RAV daily for about 1.5 years now (about 20,000 kM) with few problems (so it was due).

My charger mains safety relay failed... The charger can be controlled in 3 ways:
- Manzanita has a constant V/Constant I profile - so if the pack volts gets high enough the charger will back down
- The Elithion BMS looks at every cell volts, and will tell the charger to turn off (while it re-balances the cells) - it also looks at the total pack volts and will turn off the charger
- final fail-safe relay (the one that failed) - the SSR relay's ground was fed from the BMS Fault signal (so if the BMS is off or Faulted, AC mains get opened).

I used a Crydom SSR relay for 240VAC, 40A - a few mornings I came out and found my GFI charger breaker had tripped... Finally sat and watched it - works for about 15 minutes, then the SSR started buzzing and eventually the GFI trips. It had a decent heat sink, so not sure why it failed...

Replaced it with a heavy ABB 3 phase contactor - the current draw on the 12V coil was too much for the Elithion FLT signal, so had to add another relay. Big clunk when I open the fuel door!

Overall a nice cleanup (3 phase relays allows 2 hots and the neutral to be switched with a single cable going everywhere).

One of my car seat heaters also failed, so probably it is next on the list...