Alibro
Well-Known Member
There are 96 cells with one wire for each cell plus a couple, plus the main link wires between each module. The modules have sockets for the BMS and temp sensor wires so I made short adaptors for each module with the cell number and module number on the wires. The two below with 22 on them are temperature sensor wires which I may or may not need but I brought them out to the plugs anyway The other wires have their cell numbers on them.
Most of the modules have bare PCB's and for these I used the adaptors made from the OEM loom.
For the master modules with the BMS circuitry I removed the PCB's to prevent them from interfering with the Leaf BMS and connected my adaptor directly to the cells.
Then I had to cut the Leaf BMS Loom where it would connect to the Leaf battery packs and fit my own connectors so this is how it looked in my office before I connected the BMS. These are the mess of wires in the previous photo.
As you can imagine this number of connectors and wires took a long time to make and check and treble check before I dared plug the BMS in. If anything was wrong the BMS would have gone Pop and released the blue smoke.
Having got this far without major incident I figured I was doing stuff that could possibly result in accidents and/or fire so moved everything into the garage. Burning down the garage would be unfortunate but burning down the house would be divorce at best.
Alibro
Well-Known Member
I eventually got round to editing and posting Video part two of the battery module BMS connections. In this video I'm making the BMS adapter cables for the eGolf Slave modules.
Unfortunately I still haven't managed to get charging working as it looks like the Nissan Leaf Gen1 onboard charger is controlled differently to the Gen2. I say that because I found a thread on the Nissan Leaf forum where an owner has been able to kick his Gen2 OBC into life but I have followed his instructions and mine is not working.
I've spent weeks on trying to get the OBC working but have decided to move on and will now concentrate on fitting the battery modules and getting the thing moving. The time wasn't completely wasted though as I've learned a lot about sending CAN messages and hopefully now have a reliable way of sending the CAN that will be needed later.
Unfortunately I still haven't managed to get charging working as it looks like the Nissan Leaf Gen1 onboard charger is controlled differently to the Gen2. I say that because I found a thread on the Nissan Leaf forum where an owner has been able to kick his Gen2 OBC into life but I have followed his instructions and mine is not working.
I've spent weeks on trying to get the OBC working but have decided to move on and will now concentrate on fitting the battery modules and getting the thing moving. The time wasn't completely wasted though as I've learned a lot about sending CAN messages and hopefully now have a reliable way of sending the CAN that will be needed later.
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Alibro
Well-Known Member
Thanks mate.
A few things happened around Christmas that knocked me back and although I never stopped working on it I kinda lost my mojo.
Hopefully getting back to it now.
Nodge68
Well-Known Member
These things are sent to try us Ali, I lost basically 9 months of last year with a bathroom refit, then I got a new and more challenging job, and I've not caught up with my projects since.
I've loads of stuff I want to complete and record, I've just not had the time or the energy, and when I have one, I don't have the other.
Alibro
Well-Known Member
In my case I had the time but lost the inclination for major works.These things are sent to try us Ali, I lost basically 9 months of last year with a bathroom refit, then I got a new and more challenging job, and I've not caught up with my projects since.
I've loads of stuff I want to complete and record, I've just not had the time or the energy, and when I have one, I don't have the other.
Like I said though I was doing small things in the background and a few weeks ago made a major step forward. I'll be making a video about it but basically I have the bms working and can see all cell voltages in LeafSpy on my phone. along with dc to dc converting to charge the 12V battery and a way to turn on the high voltage using a couple of small 12V timer relays. Basically all the major things that were stopping me moving on apart from charging.
I was going to try and link a load of 19V laptop chargers in series to charge the HV but when I tested it at 100V it didn't work. I had 5 in series but as soon as I connected them to the batteries they shut down.
so I'm now looking for plan C, ie an Outlander PHEV charger which have already been cracked.
Alibro
Well-Known Member
The Leaf charger refused to kick into life when I plugged in the EVSE granny cable. I could see a small change to the CAN coming from it but couldn't persuade it to charge the battery.
I have access to a lot of laptop chargers so I wanted to see if I could use them to create a temporary charger so for a test I tried linking 5 x 19V laptop chargers to give around 96V.
I then linked 6 of the 4S modules which gave a battery pack voltage around 92V but when I connected them the chargers all shut down.
I know this is probably a bad idea but thought it was worth a try. Since then I've seen someone charging a 12V battery with a 19V charger by putting a 12V light bulb in series with it. They had to monitor the battery voltage to stop it overcharging but if I got the numbers right I wouldn't need to worry about that.
I might give this a try later.
Nodge68
Well-Known Member
Ok, I've got it now.
Your batteries wanted more current than the laptop power supplies could supply, so one of them will have shut down, assuming a short on the output lead.
Using a light bulb filament as a resistance, you can control the current supplied, simply by selecting a bulb with a suitable resistance. Bulbs used in this way are really effective at limiting current, because of how the filament works. However be aware that as the filament warms up, it's resistance increases, which lowers the current throughput.
I initially used a bulb in line with a solar panel to charge a lithium battery in my solar accumulator project, as it worked as an effective charge controller. However the heat generated seemed to me to be a waste of energy, so I moved to a charge controller instead.
I'll have a think about this issue.
Your batteries wanted more current than the laptop power supplies could supply, so one of them will have shut down, assuming a short on the output lead.
Using a light bulb filament as a resistance, you can control the current supplied, simply by selecting a bulb with a suitable resistance. Bulbs used in this way are really effective at limiting current, because of how the filament works. However be aware that as the filament warms up, it's resistance increases, which lowers the current throughput.
I initially used a bulb in line with a solar panel to charge a lithium battery in my solar accumulator project, as it worked as an effective charge controller. However the heat generated seemed to me to be a waste of energy, so I moved to a charge controller instead.
I'll have a think about this issue.
Alibro
Well-Known Member
I think I may have just killed 5 psu'sOk, I've got it now.
Your batteries wanted more current than the laptop power supplies could supply, so one of them will have shut down, assuming a short on the output lead.
Using a light bulb filament as a resistance, you can control the current supplied, simply by selecting a bulb with a suitable resistance. Bulbs used in this way are really effective at limiting current, because of how the filament works. However be aware that as the filament warms up, it's resistance increases, which lowers the current throughput.
I initially used a bulb in line with a solar panel to charge a lithium battery in my solar accumulator project, as it worked as an effective charge controller. However the heat generated seemed to me to be a waste of energy, so I moved to a charge controller instead.
I'll have a think about this issue.
I tried connecting them with a 12V halogen headlight bulb in circuit and now none of them will turn on. The psu's were putting out 99V while the batteries were 92V.
Oops
Nodge68
Well-Known Member
I think I may have just killed 5 psu's
I tried connecting them with a 12V halogen headlight bulb in circuit and now none of them will turn on. The psu's were putting out 99V while the batteries were 92V.
Oops
I think for the testing you're currently doing, it would be best to get a suitable bench power supply.
These allow you to adjust the output voltage and importantly the output current limit.
I couldn't do anything related to batteries without my bench power supply.
Something like this.
https://www.ebay.co.uk/itm/Laborato...=p2349624.m2548.l6249&mkrid=710-127635-2958-0
Also you need to start small with light bulbs, so start with a 5 or 10 Watt bulb, and go from there.
Alibro
Well-Known Member
It turns out I tripped the breaker in the house so I must have messed up somewhere. I'll have another go with a smaller wattage light bulb like you suggest.
In theory it only has 7V across it so the current shouldn't have been high but I'll try your suggestion anyway.
I should get a decent bench PSU for other projects but this was just a test to see if it would be possible to string together multiple laptop PSU's (which I have a lot of) to charge a high voltage battery. It would never be a satisfactory way to charge the car but I figured it might be worth a try.
Alibro
Well-Known Member
Woo Hoo!
It does work after all. I'm not sure what I did wrong last time but here is it working
It's all a bit dodgy looking but I'm seeing 3A and 92.3V at the batteries and 98V at the psu side of the lamp.
These are 6.9A psu's so are well within their comfort zone and the voltage is slowly rising at the batteries.
It does work after all. I'm not sure what I did wrong last time but here is it working
It's all a bit dodgy looking but I'm seeing 3A and 92.3V at the batteries and 98V at the psu side of the lamp.
These are 6.9A psu's so are well within their comfort zone and the voltage is slowly rising at the batteries.
Nodge68
Well-Known Member
What's the capacity of the batteries used in the golf pack Ali?
Your bulb set-up is very much like Julie Illet is using to limit current on his charge system at the moment.
GrumpyGel
Well-Known Member
Is your next project to create a 21st century Frankenstein's monster?
Alibro
Well-Known Member
I must have a look at that.What's the capacity of the batteries used in the golf pack Ali?
Your bulb set-up is very much like Julie Illet is using to limit current on his charge system at the moment.
The battery pack in the eGolf is around 35kWh but I've added just over 3kWh by adding two 4S modules.