[gdirwin]

Thanks Dragster - in addition to KISS, I also like to keep it safe (and protect my investement in batteries).

It is a personal decision - go simple and just do initial balancing, or to make things more complex and have active monitoring. I have decided to spend bucks on a BMS which continually monitors each cell, and will take action if any cell gets too high or too low. You are correct that I will probably have more failures this way, but I will get immediate notification that something is amuck and then fix it. No chance of a problem sitting undetected and possibly ruining a cell.

Perhaps someone with many years of hands-on experience in using these cells may save the cost and complexity of a full-blown BMS - I do not have this experience yet. I certainly hope my cells all stay balanced and I do not have any high or low excursions - if so I will be most happy!

I can imagine a day (probably in the near future!) where I am stuck somewhere with a BMS error that will not let the car drive - I will make the contactor relay ground connections accessible so they can be easily connected directly to ground (thus removing the BMS from the loop) so I can get home. Time will tell...

 

[dragster]

Hi
I like your idea on the disconnect also you may think about a timer shut off for the power to the charger. If your not there when the batteries should be fully charged then the timer will shut off the charger so as to protect the batteries from over charging. Cost $172.79 for 110 volt time 0 to 15 hours. Available at McMaster-carr

 

[gdirwin]

I have a Manzanita PFC40M Charger (40A, 120 or 240V) with a backup external SSR relay (relays are expensive at this rating!). The BMS controls the charger on/off through the REGBUS (a low voltage interface) - as a backup, the FLT signal from the BMS (this is a normally grounded connection) is used to control the SSR relay. If a fault occurs (a wire breaks, the BMS controller senses a cell that is over-charged etc...) then the ground gets removed and the SSR relay opens.

I could easily add a timer into the SSR relay signal - when you open the fuel door to initiate charging, it would start a timer and ensure the charger gets turned off after X hours.

This feature is already added in the PFC charger, but it has to be disabled (because the BMS can turn the charger on/off/on/off during balancing - if the internal timer is used, then it cannot be turned on again).

Thanks - good idea! Do you know of a good 12V timer? When it receives a 12V input, it should output 12V for X hours, then turn it off.

 

[gdirwin]

The Zilla works well (at least with the wheels still in the air) if I bypass the BMS by grounding both relays (instead of using the FLT and LLIM signals from the BMS).

I will focus on the BMS wire shielding next - hopefully solve the com problems with the BMS...

 

[gdirwin]

Got into an accident yesterday - icy roads. Not much of a bump, I was stopped, but got hit directly on my front right tire.

Front right quarter panel got munched, as well as the strut, rim, tire, CV joint, tie rod etc... I am not sure if the CV joint pushed into the transaxle or not, or if the steering gear is damaged.

Fortunately no one was hurt, and all of the EV stuff appears to be okay. My inertia switch tripped and opened both contactors. After resetting it, I could move the car about 5 ft to get it off the road.

Will see how the insurance company assesses damage - probably have to replace both struts and all 4 tires (as it is AWD) but not sure if they will pay for this or not...

I had a grand total of 980 kM on it in the last two months since I got it running. One thing that doing an EV conversion has taught me - anything can be fixed - no biggy I hope.

 

[mikep_95133]

Hi gdirwin,

Did you get your vehicle repaired successfully? How did the insurance company handle it?

I like your schematic of the dual ceramic heaters. I really want to go with a similar config in my truck. Mine useds the stock heater core and heats the water. Factory set up that way. I did upgrade the heater. It works alot better, but it's always at 100% output when it's turned on. No way to modulate the use of power.

I was thinking of using pwm to drive the dual ceramic cores. You mentioned that earlier in your thread, but it appears you took a different route to control your heaters. Can you tell me why? My issue is that my pack runs from 400vdc to as low as 200vdc. So it looks like a Crydom d4d12 would work for the switching. A pwm input, variable duty cycle, signal is easy to generate. May have to use some IGBT's instead of the Crydom due to peak current at startup of heater.

What kind of current do your heaters pull? Do they in fact warm the interior as you had hoped?

My truck has the MR2 power steering pump as well. Did you connect the speed sensor electronics as well? Mine is just relay controlled.

Thanks for your hard work!

Mike

 

[gdirwin]

Hi Mike:

My RAV is almost back from the shop after the accident - all damage was to stock OEM parts, so the EV stuff was not affected. Hopefully early next week.

I had a good experience with the insurance company (MPI - a Manitoba provinicially owned utility). The vehicle cost is quite low and by itself it would have been a marginal repair. I sent them receipts for all the EV stuff, and they had no problems in authorizing the repairs after this. They considered it like a taxi - base vehicle cost plus improvements (even though in my case the improvements were many times higher than the vehicle cost). In general they have been good to work with - they offer low rates and good service (an advantage compared to private insurance I think). The passenger side strut was damaged, and you have to replace struts on both sides (for safety/handling reasons) - I am still waiting to see if they will replace the driver side strut. For any parts which naturally wear, I had to pay a "betterment" fee - about 30%.

I am now using the PWM heater controller - it works well and gives a continuous/variable control of the heat to control the voltage to a set-point. This sounds ideal in concept, but in practice (in Winnipeg where the winters are very cold) I find that when you want heat, you want as much as you can get as fast as you can get it (perhaps for defrost etc..)... I do not drive long distances (maybe 15 minutes) and this is not long enough for the car to get "too hot". When you first turn on the heat, it starts at 0 output, and takes a minute or 2 for the PI controller to ramp it to 100%. There is a manual over-ride to manually set the output - you press and hold an arrow button and it switches to manual mode (a bit cumbersome). I pre-heat the vehicle with a separate AC interior heater (using an on-board timer) and added electric seat heaters. Keep in mind that we get extreme cold up here - snow on the ground from Oct to March, and AVERAGE temps in Jan around -18C (-4F) without a wind chill factor - it dips to -40C (-40F) for a few weeks every year - 2 heater elements for an EV in San Jose will be more than enough.

I have not measured the current from the heaters - my pack is less than 200VDC, and I use the Cyrdom D2D40 relays. Note that the current ratings are very sensitive to temperature and heat sinks (mine are mounted with a thermal compound and bolted to an alum heatsink). I thought I would use higher current SSRs to have something more robust.

Overall the heat is excellent - it gets going quickly and is quite hot - good enough for -40C winter driving I think. It is hotter than a ICE for most of the time (because you do not have to wait for it to heat up), but not as hot as a car that has been running for 2 hours.

I have the power steering pump speed sensor ready to be connected, but have not connected it yet... To be honest, I find the MR2 pump very noisy (even when it is just sitting there with no steering wheel pressure) and drive with the power steering turned off 99% of the time - I only turn it on for parallel parking etc... I have switches for the P/S and P/B relays inside the cabin.

Your pack varies from 200 to 400 VDC? Seems like a wide range... Presumably you will use ceramic heaters from a 220 VAC heater then?

 

[mikep_95133]

Hi Mike:

My RAV is almost back from the shop after the accident - all damage was to stock OEM parts, so the EV stuff was not affected. Hopefully early next week.

I had a good experience with the insurance company (MPI - a Manitoba provinicially owned utility). The vehicle cost is quite low and by itself it would have been a marginal repair. I sent them receipts for all the EV stuff, and they had no problems in authorizing the repairs after this. They considered it like a taxi - base vehicle cost plus improvements (even though in my case the improvements were many times higher than the vehicle cost). In general they have been good to work with - they offer low rates and good service (an advantage compared to private insurance I think). The passenger side strut was damaged, and you have to replace struts on both sides (for safety/handling reasons) - I am still waiting to see if they will replace the driver side strut. For any parts which naturally wear, I had to pay a "betterment" fee - about 30%.

I am now using the PWM heater controller - it works well and gives a continuous/variable control of the heat to control the voltage to a set-point. This sounds ideal in concept, but in practice (in Winnipeg where the winters are very cold) I find that when you want heat, you want as much as you can get as fast as you can get it (perhaps for defrost etc..)... I do not drive long distances (maybe 15 minutes) and this is not long enough for the car to get "too hot". When you first turn on the heat, it starts at 0 output, and takes a minute or 2 for the PI controller to ramp it to 100%. There is a manual over-ride to manually set the output - you press and hold an arrow button and it switches to manual mode (a bit cumbersome). I pre-heat the vehicle with a separate AC interior heater (using an on-board timer) and added electric seat heaters. Keep in mind that we get extreme cold up here - snow on the ground from Oct to March, and AVERAGE temps in Jan around -18C (-4F) without a wind chill factor - it dips to -40C (-40F) for a few weeks every year - 2 heater elements for an EV in San Jose will be more than enough.

I have not measured the current from the heaters - my pack is less than 200VDC, and I use the Cyrdom D2D40 relays. Note that the current ratings are very sensitive to temperature and heat sinks (mine are mounted with a thermal compound and bolted to an alum heatsink). I thought I would use higher current SSRs to have something more robust.

Overall the heat is excellent - it gets going quickly and is quite hot - good enough for -40C winter driving I think. It is hotter than a ICE for most of the time (because you do not have to wait for it to heat up), but not as hot as a car that has been running for 2 hours.

I have the power steering pump speed sensor ready to be connected, but have not connected it yet... To be honest, I find the MR2 pump very noisy (even when it is just sitting there with no steering wheel pressure) and drive with the power steering turned off 99% of the time - I only turn it on for parallel parking etc... I have switches for the P/S and P/B relays inside the cabin.

Your pack varies from 200 to 400 VDC? Seems like a wide range... Presumably you will use ceramic heaters from a 220 VAC heater then?

So you ended up using something like an Omega controller? Which model did you get?

I suppose buying the fet based Crydom SSR's is easier. I was thinking of using some fet's that I use in my chargers that are 44a and 500v.

Heaters here have a bit of a heat load with the humidity. I'm wanting quick rise time from my heater. I suppose I would have to try and find 240vac ceramic heaters. My water based heater is 240vac. It works fine.

Any idea where to get 240 vac ceramic heaters?

How complex is the speed sensor hardware to adapt to your vehicle? Those pumps say 10v on them. At 14v they sure do scream.

These flooded nicads do have a wide range of operation. I usually run about 260-330vdc. But fresh off of the charger it comes down from 400v. A nearly dead pack will produce 200vdc.

Mike

 

[gdirwin]

I got this one:
http://www.auberins.com/index.php?m...id=132&zenid=ac51b85556d4417f284e1738ad210b14

They also have a smaller 1/32 size, but it has fewer buttons and is a bit more cludgy. The 1/16 size shows the temp set-point and measured temp as well. They can both be purchased with 12V DC power.

As I said, they work well, lots of features, but it takes time to ramp up from 0.0 to full on, and the manual mode is a bit cludgy. Omega controllers also looked good, but were a lot more money. They may be easier to use in manual mode though?

220V ceramic heaters are common in Europe - 50 Hz or 60 Hz does not matter. Since you have 2 elements and with PWM control they are both used all the time, you could just connect your 120V ceramic elements in series. Now that I think about it, the wide voltage range of your floodies is similar to LiFePO4 (max 3.8V to a min of about 2.5V). Fully charged my pack is 175V - a 120V rms AC heater would have a peak voltage of 120*sqrt(2)=169.7 - this is a nice match. In your case with 2 of these in series (instead of used in parallel as with my setup) you would have no problems up to at least 339V. You mentioned 400V - I do not think this is too much higher and may be okay - it corresponds to an AC voltage which is 17.8% higher than 120V...

My car is a 2001 Toyota RAV4, so the power steering speed sensor signal should be the same as what is required for the newer MR2 pump - the wire color is the same as well... I have not tested this yet though.

 

[mikep_95133]

I got this one:
http://www.auberins.com/index.php?m...id=132&zenid=ac51b85556d4417f284e1738ad210b14

They also have a smaller 1/32 size, but it has fewer buttons and is a bit more cludgy. The 1/16 size shows the temp set-point and measured temp as well. They can both be purchased with 12V DC power.

As I said, they work well, lots of features, but it takes time to ramp up from 0.0 to full on, and the manual mode is a bit cludgy. Omega controllers also looked good, but were a lot more money. They may be easier to use in manual mode though?

220V ceramic heaters are common in Europe - 50 Hz or 60 Hz does not matter. Since you have 2 elements and with PWM control they are both used all the time, you could just connect your 120V ceramic elements in series. Now that I think about it, the wide voltage range of your floodies is similar to LiFePO4 (max 3.8V to a min of about 2.5V). Fully charged my pack is 175V - a 120V rms AC heater would have a peak voltage of 120*sqrt(2)=169.7 - this is a nice match. In your case with 2 of these in series (instead of used in parallel as with my setup) you would have no problems up to at least 339V. You mentioned 400V - I do not think this is too much higher and may be okay - it corresponds to an AC voltage which is 17.8% higher than 120V...

My car is a 2001 Toyota RAV4, so the power steering speed sensor signal should be the same as what is required for the newer MR2 pump - the wire color is the same as well... I have not tested this yet though.

I hesitate using 2 heaters in series. If one of them fails, then I have to tear the whole dash apart. I want 3k watts. So I was thinking of 2 1500w 240vac units in parallel. I'll start scouting around for elements.

Mike

 

[gdirwin]

I hesitate using 2 heaters in series. If one of them fails, then I have to tear the whole dash apart. I want 3k watts. So I was thinking of 2 1500w 240vac units in parallel. I'll start scouting around for elements.

Mike

Hi Mike:

Look carefully at the heater core location - in my RAV, the manual said to remove the entire dash, A/C etc... - but a lot of this work was due to the aluminum pipes that feed the core - in fact I could have removed the core (with the coolant pipes cut) quite easily... I have not heard of anyone with failures, but I agree that 2 in parallel would be better then 2 in series...

 

[mikep_95133]

Good point to look at the heater core to see if it will come out with the plumbing sawed off, easier.

I have not heard much in the way of failures, but I also don't hear much in the way of data in general either on ceramic heaters. Just that a single 1500w is many times not enough. My notes show 2800w on mine. But so much more indirect heating water. Maybe I'll head to my 'training grounds' and attempt to take one out at the junk yard first. $24 used at my local yard and new for $40 at Kragen. I should hit up a radiator shop for a leaking one.

Mike

 

[gdirwin]

Got my car back today - almost $7,000 in damage - basically a new front end (new struts etc...).

Frontier Toyota did a great job - they gave me some discounts on the driver side stuff (strut etc..) and labor (not paid for by insurance). Nice paint, and they shined up the rest of the car. Good alignment, absolutely no concerns so far.

A big relief!

Bought new snow tires all around (Nokian Hakka's) - went to install them today, but the lug nuts for the aluminum mags do not seem to fit well on the new black steel rims for the winter tires... Will install tomorrow.

 

[RKM]

Garth,

Glad to hear you're almost back on the road! I've used Nokians for years and think they are the best snow/ice tires. I have four on the Miata too. In 4WD, you'll be almost unstoppable.

Rob

 

[94Tracker]

Oh man "unstoppable"? Thats not good you want to be able to stop better don't you? Seriously I run winter tires so I can stop and handle better than "all season" tires. Didn't help my daughter the other day as she introduced her Echo's front bumper to the hitch of the truck in front of her. Minimal damage everyone fine.

Garth, we spoke when you were looking for your Rav, I had a 04 Chili for sale. Glad to see you have it on the road but you should have waited much longer to "modify" the body. I've had good experiences with Frontier's body shop too. Is Julie still managing it?
Glen

 

[gdirwin]

Oh man "unstoppable"? Thats not good you want to be able to stop better don't you? Seriously I run winter tires so I can stop and handle better than "all season" tires. Didn't help my daughter the other day as she introduced her Echo's front bumper to the hitch of the truck in front of her. Minimal damage everyone fine.

Garth, we spoke when you were looking for your Rav, I had a 04 Chili for sale. Glad to see you have it on the road but you should have waited much longer to "modify" the body. I've had good experiences with Frontier's body shop too. Is Julie still managing it?
Glen

Hi Glen:

Julie is there - I worked with Dan (general manager) and Don (in parts), and Chris did a lot of the mechanical work - I found everyone there most helpful and they did great work - a pleasure!

There is a MEVA meeting on the 27th (last Thursday of each month) - not sure if RKM/Rob will be there with his Miata (great conversion!) as well as Gerry with his BMW... Maybe see you there?

Nokian Hakka tires are wonderous - great stopping power... The new tires are a bit higher and narrower - I run with the power steering pump off a lot, and I find it does not wander as much (ie catching ruts in the road etc...).

 

[RKM]

To continue the Nokian commercial....

I regretted my choice of choice of words almost right away, "unstoppable". I agree that steering and braking are the critical advantage to good snow/ice tires. Being able to go is another benefit!

I bought our first set of Hakkapelita Q Nokians after a 15 cm snowfall on top of ice. I had been planning to buy the "WR" Nokians, which are good but which can be driven in the summer as well. On my drive over to the tire shop, the car felt like a curling rock as it would gently slide along with the brakes applied. I thought I'd be lucky to get to the tire shop without bumping into something or being bumped into. I called my tire guy (while parked) to change the order to "the best you've got". It was a night and day difference.

Under most winter driving conditions, our little front wheel drive car, with good snow rubber, is far better than the 4WD truck. The truck will handle more deep snow, but the car will stop and steer far better.

See you on the 27th.

Rob

 

[gdirwin]

Yesterday was not a good day... Went to pick up my car from the dealership (the new steering gear they replaced from the accident was leaking, so it was replaced and needed an alignment). It was left outside at -30C overnight. In the morning it would not start - Zilla errors.

Got some help from Toyota, who pushed it into a warm garage - after less than 2 minutes of warmth, it started! This got me home, but there was a lot of battery sag, low volts during acceleration etc...

Plugged in for just a few hours, then went to our local EV association meeting (MEVA) - when I came out, it would not start - tried everything, no go. Fortunately RKM stuck around, and gave me a ride home (thanks Rob!).

Came back with my helpful neighbor (thanks Serge!) and we put big heaters on it etc... but still got an error from the Zilla - error 1234 was not in my manual. It went to -30C that night - no fun. Gave up, towed it home. It is now 2 am.

The new Zilla manual from cafeelectric says the error was "Motor voltage is high on startup" - made no sense.

I realized I had about 80 kM on the pack (home, to out-of-town bodyshop, they drove it to the dealership, back home, then to MEVA meeting), which is more than I normally drive. Combined with very cold temperatures, not plugged in (ie no battery warmers) meant the pack was "on fumes" - I thought the sag was just ultra-cold weather, but it was a bit of both.

I am hoping the Zilla 1234 error really means "battery voltage too low" and not "Motor voltage is high on startup". It is on the charger now (tucked at home in my garage) so will check this am.

Learned another lesson - the battery was drained to a bit less than 3V per cell (still in the safe range, but on fumes). My BMS settings are still very conservative, so this triggered a fault (one cell was on undervoltage) - this does 2 things:
- any BMS fault removes the ground from my negative contactor
- any BMS fault removes the ground from an AC relay on the charger

The idea was that this was a fail-safe - any FLT and you can't drive or charge. Well, if you have an undervoltage error and can't drive (good) but you also can't charge, not good. I had to connect a PC, clear the FLT, then charge... Eventually with a dash PC that would be convenient, but it was not convenient last night at -30.

I will put BMS/Manual switches on the -ve contactor (this was there already actually) and on the charger AC relay - this way I can bypass the FLT signal, ground the relays, and proceed...

Not a good day to do a range test! Will report more on my 1234 error when I get info...

 

[gdirwin]

My faithful Zilla has continued with cold-weather errors - Otmar has been excellent to track stuff down...

I pulled both the power unit and the hairball - likely a pre-charge relay needs replacing in the hairball. Apparently all power units that were made by (now defunct) EV Components had a bug where it would cut out with an error under some conditions when the throttle was 100%. Earlier I received a Hairball patch firmware that limited the throttle (so avoided the error) but I figured I would get the bug fixed at the same time (which requires sending the power unit back as well).

I will add any updates about cold-weather use... Otmar has been great!

 

[gdirwin]

Got the Zilla back today - Otmar repaired a bad trace (moisture freezing and causing a bad connection) and the pre-charge relay.

Will put it in this weekend, but first I will try to design a plastic box around it (even though it seems well protected now) to improve the moisture-resistance.

I also will be adding some conformal coating onto the board where wires come in...

After driving all winter, I w nohate driving an ICE - it is painful to go to a gas station and fill-er-up!