Freelander 1 Freelander EV

andyfreelandy said:

Good luck with the new buggy. I've always got a supply of Freelander 1's should you realise you've made a mistake

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I don't suppose you have a spare pedal set for an Auto do you? Having a bigger brake pedal would be nice.

Sorry Ali, never stripped an auto.

andyfreelandy said:

Good luck with the new buggy. I've always got a supply of Freelander 1's should you realise you've made a mistake

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And Ali can whip the motor out of the IONIC and put it in the Hippo.

andyfreelandy said:

Good luck with the new buggy. I've always got a supply of Freelander 1's should you realise you've made a mistake

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I'm still on the lookout for a good condition Sport premium hardback, preferably a 1.8.

I put a few miles on the car over the weekend.

I always wanted this to be a practical workhorse that I don't need to be too precious about


Every time I use it to tow a trailer it's another time I don't burn out a little bit more of SMBO's Kuga clutch.

you need to remove the "S" from the badge now.

The last few days I've been struggling to get my head around the BMS again. Although it probably won't be able be able to keep the pack balanced it's a good idea to have it working as I can use a simple Bluetooth dongle and App called LeafSpy to monitor the voltages of each cell. Having the BMS working means I'll be able to see if any cells are out of balance and if necessary I can intervene manually. I really should have had it sorted months ago but I knew it was going to be a pain so kept putting it off. I had it connected and working a couple of years ago on the bench but that was with all the modules in one place. Now I have some in the front, some in the fuel tank area and some in the boot so it's not so simple.
During the week I spent several evenings working on it and then pretty much the entire day today soldering testing, pulling apart and resoldering cause I messed up.
This was the mess I was in earlier.



After many cockups, a few poor decisions and some generally dodgy workmanship I think I have it sorted.
Some time ago I made up a spreadsheet to give me the expected voltage at every connection for any given cell voltage. I was able to test all the voltages and even discovered a fault in the spreadsheet so tomorrow I'll sort out a 12V supply for the BMS, hook up the CAN leads and hopefully see the condition of the battery pack.

Wish me luck

Alibro said:

The last few days I've been struggling to get my head around the BMS again. Although it probably won't be able be able to keep the pack balanced it's a good idea to have it working as I can use a simple Bluetooth dongle and App called LeafSpy to monitor the voltages of each cell. Having the BMS working means I'll be able to see if any cells are out of balance and if necessary I can intervene manually. I really should have had it sorted months ago but I knew it was going to be a pain so kept putting it off. I had it connected and working a couple of years ago on the bench but that was with all the modules in one place. Now I have some in the front, some in the fuel tank area and some in the boot so it's not so simple.
During the week I spent several evenings working on it and then pretty much the entire day today soldering testing, pulling apart and resoldering cause I messed up.
This was the mess I was in earlier.

View attachment 317348

After many cockups, a few poor decisions and some generally dodgy workmanship I think I have it sorted.
Some time ago I made up a spreadsheet to give me the expected voltage at every connection for any given cell voltage. I was able to test all the voltages and even discovered a fault in the spreadsheet so tomorrow I'll sort out a 12V supply for the BMS, hook up the CAN leads and hopefully see the condition of the battery pack.

Wish me luck

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I would not have the bandwidth or storage capacity in me head to work through that lot!

GrumpyGel said:

I would not have the bandwidth or storage capacity in me head to work through that lot!

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If you can connect one wire you can connect two. If you can connect two wires you can connect five. If you can connect 5 wires....... you get the point.

It looks daunting and complicated but when you break it down it's just connecting wires. There are four rows of modules in the boot with 8 cells per row so 32 cells all together, I had to extend the wires and used two lengths of 25 way multicore so had 64 connections to make. Each one is soldered then insulated with lengths of two heat shrink, (to be sure to be sure).

My problem was caused by the numbering convention by Nissan, they count the most positive cell as cell 1 and most negative as cell 96. The lowest number cell in the boot is 41 so I started there when I should have started at 96. I figured trying to meter and count the voltage from cell 96 to 41 would be too complicated so I metered from the most positive end and managed to confuse myself completely. Eventually I dug out a spreadsheet I had created almost two years ago which gives the voltage at each cell for any given single cell voltage. Once I had this in front of me it all started to make sense.



I got the connection numbers from the Nissan Leaf service manual and it worked before so I'm confident it is correct but another complication is at cell 48. There is an extra negative connection for cell 48 because the BMS is galvanically isolated between cells 48 and 49, to protect it from stray current drain when the HV service disconnect is pulled. Basically if this was not there the BMS would be shorting out the HV service disconnect, thereby maintaining the HV circuit, This would not only be dangerous but if there were a stray power drain it would melt the BMS.
My service disconnect and contactors break the pack at cell 41/42 so I have to try and figure out a way to ensure the BMS is never connected when the contactors are open. I'll probably use a relay to make/break the connection to cell 49 and ensure it is only ever active while the car is in drive mode.

Regarding the bms breaking at cell 48, a suggestion has been made to move the neg contactor in the rear battery box (that is probably overkill anyway) to between cells 48 and 49. This should protect against accidental damage to the bms and would be fairly simple and easy to do.
Hopefully I'll get a chance to look at this tomorrow, today I spent the morning refitting the rear offside control arms and had a go at setting the tracking with the help of some string.



Note the multiple plastic bags under the wheel to let it turn freely.



From I first drove this car it has been pulling to the left and a couple of weeks ago with the help of a length of string I discovered the rear offside wheel was towing in a by a fair amount and the front offside was towing out. I tried to adjust the rear wheel first but (despite trying heat and abuse) couldn't get the adjuster to move so ordered a new track control arm and long bolt that I knew would be destroyed getting it out. Unfortunately the bolt was seized solid to the 2nd control arm so I ended up ordering a new one of those too.

After an hour or so working at it I have the tracking close but not perfect as it is still pulling slightly to the left but not as bad as before. At some stage I plan to get new tyres so will have the tracking set properly then.

So good and bad news for the BMS.
The good news is it's working. I can see every cell and have been able to manually drain a few that were too high. They were maybe 40 or 50mV higher than average so not disastrous but bad enough to potentially do harm if the pack were fully charged as they could have been slightly over 4.2V. This is not a major issue so long as they don't drift higher and get really out of balance. I'm pretty certain that I've caught them in time.

The bad news is that with my pack layout the BMS can only be accurate at around 0A so I will need to disable it when driving or charging which is not ideal. This is due to the resistance of the contactors cable and fuse in the wrong position as far as the bms is concerned and the length of the cable. I think moving the neg contactor to between cells 48 and 49 will protect it from harm when the car is turned off but can't help when it is on. There should be almost zero resistance between all the cells and I have a measurable resistance between cells 40 and 41 due to a fuse, contactor, manual disconnect and around 5m of cable being between them.
I'll probably fit a switch somewhere to turn the BMS on and off when I want to check the pack but in the meantime I'll just pull the fuse for the BMS once I'm happy the pack is balanced.


This was the output from LeafSpy earlier (While charging) You can see cell 40 looks odd but this is because of the resistance in the cable etc.
Three of the modules are higher the the rest, two 4S and one 2S.



And this is it now.



I am still draining the two highest cells with a buck converter set to 150mA.

I'm still draining those pesky last two cells to try and get them to average. It is a pain but I'm getting there.
Unfortunately that's more than can be said of the car as I went to use it today and it cut out again this time in the middle of a roundabout. I thought I had sorted that issue but it looks like either I did something silly while wiring in the BMS that caused it to fail again or I need to rethink my cheap Chinese timer module strategy since I believe these are the root cause of the issue.
Maybe something as simple as a large capacitor across the input would stop them glitching.

Alibro said:

I'm still draining those pesky last two cells to try and get them to average. It is a pain but I'm getting there.
Unfortunately that's more than can be said of the car as I went to use it today and it cut out again this time in the middle of a roundabout. I thought I had sorted that issue but it looks like either I did something silly while wiring in the BMS that caused it to fail again or I need to rethink my cheap Chinese timer module strategy since I believe these are the root cause of the issue.
Maybe something as simple as a large capacitor across the input would stop them glitching.

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I read everything you post....


And understand very little.


I take it that kicking it didn't get it to start?

GrumpyGel said:

I read everything you post....


And understand very little.


I take it that kicking it didn't get it to start?

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It got kicked plenty but no it didn't help.
Funny old thing but turning it off and on again did.
I think the issue is being caused by a little timer module that is extremely susceptible to fluctuations in voltage which can be caused by the vacuum pump kicking in.

These things.

I'm going to try putting a 25V 1500µF capacitor across the 12V supply for it to see if it helps.

Ali, add a little 100nF ceramic capacitor as well. The large one will smooth the supply, but you need the smaller ceramic for high freq noise immunity.

Used this concept many times on audio amps years ago !! I even made a wiper delay module for my old XJ6, that measured the time between manual wipes, and then did the intermittent at that interval. (no mini cpu's around back then)

pwood999 said:

Ali, add a little 100nF ceramic capacitor as well. The large one will smooth the supply, but you need the smaller ceramic for hight freq noise immunity.

Used this concept many times on audio amps years ago !! I even made a wiper delay module for my old XJ6, that measured the time between manual wipes, and then did the intermittent at that interval. (no mini cpu's around back then)

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Thanks mate, I'll do that.
I put the 1500µF cap in earlier and it seems to be working a treat, completely preventing the drop out I could see earlier, goes to show how poor quality the modules are so I'll probably figure out a way to get rid of them.