Category: Research

So, so more thoughts on the new pack.  I don’t want to have liquid cooling – I’ve already got enough problems with cooling the motor and controller. This takes out the Tesla batteries as well as the Volt/Bolt batteries.  Also, it just doesn’t get as hot in Santa Cruz as it does in San Diego.

However, it does get cold – we’ve had near freezing weather for the last few weeks, and that is not good for driveability (or for the number of amps you can draw).

So I’ll have to heat the pack somehow – this will be built into the pack from the start this time. My thought is to use some kind of ceramic heating pad (gardening shop here I come) under the batteries.

I also want a full-fledged BMS this time as well – the miniBMS did what it promised (tell me when something is wrong but nothing else) – but that isn’t good enough. I need to know which cell is failing, and to be able to do trending on the cells’ capabilities.

Research continues!

Living in San Diego I didn’t expect to have to deal with cold batteries.  Turns out the CALBs do not like getting under 45F – they really can’t produce the current I need to drive the car – setting off the miniBMS alarm.

I’m working with a machinist to come up with some insulation for the rear pack, and adding some heating to the packs.  Simplest solution is to use plant seedling mats – they heat up whenever the temp drops below 74F.  However, I couldn’t use mats due to the criss-cross of support beams.  Solution:  use soil heating cable.  The cable I bought has a built-in thermostat and can cover up to 10 square feet.  So now, all I’ll have to do is plug in the car each night – something I already do.  🙂

So when you design your pack, make sure you add in the heating lines for cold weather, as well as the necessary insulation.

Well, my mechanic informed me that the shops that would do computer-controlled CNC are backed up for 2 to 4 months.  So he’s going to do it the old fashioned way – milling machines and measuring.  This is, of course, for the new motor adaptor for the new motor.  Hey – with luck I’ll be driving the new motor by New Years.  🙂

As promised, here is the diagram with relays so you, too, can spin your GLEC motor.

GLEC_Relays

Thanks for all the help – I hope this helps others as well.

Well, remember the nice solid copper battery interconnects I hand-made?  And how some people said I needed to use braided cable?  Well, after doing Yet More Research, they were right.  The problem is that batteries move – all the time – even if you have them strapped.  Mine aren’t strapped.  So if batteries move, and the interconnects don’t, the batteries eventually get damaged.

So, in an effort to build some new ones, I tried two techniques:  wrapping copper plate around the cable, and crimping copper pipe to the cable.  As you can see from picture, the pipe does a lot better job.  The pipe crimps nicely to the cable, and doesn’t leave much sticking up (unlike the plate).

So – only 106 more connectors to build.

I finally got some spare time and opened up the controller to see what I could see.
I have a clearer understanding of what most of the lines do – but still do not know where to hook up the accelerator pedal lines. There are 6 lines called “Function” that lead to KB5, KB6, KB7, KB8 and two unmarked inputs on the controller. Not much help there.
I also have a rough idea about the serial lines – three lines that are labeled “gorge line transmit, receive and place” which are hooked to T2OUT, R2IN and one unlabeled wire.

 

 

 

Ok, since people have been asking for it, I’m posting the manual, the canbus info and the torque curve.

Manual.

CANBUS.

Torque Data.

Hopefully this will work out for everyone.  Please go gentle on my server.

After helping set up a plant sale at Balboa Park, my wife and I made a stop at the Kick Gas Club.  Neat little shop set up by a retired mechanic that specializes in helping people convert their car to electric drive.  The purpose was to see if they could help me with the motor adaptor (which they can’t right now), but they did give me some good ideas on how to proceed.

(BTW – if you are going to get a brand new motor – see if someone else has used it first and get their feedback before putting money into it).

The club can be found here:  http://kick-gas-club-electric-conversions.com/index.html

Well, for my system, there aren’t a lot of choices.  Do a google search for “Lithium Battery Monitor” and you’ll find about 3 vendors.  Since I can’t seem to get Elithion to work, I’m going with the MiniBMS from CleanPowerAuto.  While it doesn’t give me all the stats that Elithion does, I very rarely look at them.  I note that Electric Blue also has a system now that will give that sort of info, but at $15/battery, that is very pricey for me.

I’m still looking into how to display the SOC (State Of Charge) of the system, and so far, I’m quite impressed with Electric Blue’s system – especially so since I can alter the programming.  Will keep you posted on what I choose for the display.

Cheers!

I’ve been playing with the Parallax Stamp computer and have come to this conclusion:  it is fun.  🙂

My main process is going to have these steps:

main:

read motor temp

if (temp < 130C) use high power, fan is off

else if (temp < 145C) use medium power, fan is off

else if (temp > 150C) use medium power, fan is on

goto main

This loop will only use 2 relays (one for fan, one for power control).  If I were to use low power setting, I’d need another relay.

I’m hoping to install the computer this weekend, but the weather may delay that (getting REALLY hot here in San Diego).  At the very least, I hope to replace the power supply for the BMS with something much smaller.

I’ve gone and purchased a small embedded computer to read the motor temperature and enable/disable the fan for the motor (www.parallax.com).  Nice stuff, very easy to work with.

However, since I now have this computing capability, why not use it to set the power settings for the controller as well?  The idea is that when the motor is cold, allow more power to flow into the motor, and when it is warm, turn down the power.  Azure Dynamics has 3 power settings available (max, norm, economy), and that is selectable by resistance into a line into the controller.

Hmmm.  This is gonna be fun.  🙂