jonny69

Literally no idea if this has ever been posted, but here it is again if so...
 

I actually saw one of these a couple of months ago. It was a bit more jacked up than that and I think it was a camper conversion. I did a double take, of course, but assumed the owner had just swapped badges for a bit of hilarity. Didn’t know they actually existed. 

I thought it was originally about the stuff piled on the roof rack (vintage suitcases, oil drum, random old tyre, bmx, hay bale etc) from that era of modded VWs in the 00s, but it has evolved to refer to the look as a whole (lowered, camber, poke & stretch, roof rack + pineapple additions, sticker bomb, 1 rusty wing, fake patina, whiff of Ankor wax etc etc. 

You can also get little spot welders off of your preferred Chinese tat site, people use them for building electro-push iron batteries.

I had a look with the scope attached but it didn't actually tell me anything extra that was useful. Good stick followed by 'bad' stick:


I guess what it has told me is that the voltage drop when the load is connected is almost instantaneous, as it happens in about 5ms. I was expecting it to be slower than that. So having cleared that up, I tested all the sticks using the basic voltmeter method, making a note of the resting voltage and the voltage after 5 seconds with the load connected. That resulted in 17 sticks which were almost identical and 3 outliers which dropped more voltage. So what I did on the outliers was got a leather punch and made some small holes in the heatshrink so I could measure the voltage across the individual cells while they had a load attached. I did the same on a good stick so I had something to compare it to. It basically showed that the bad sticks had a single weak cell in them that was dropping a lot more voltage under load:
Good one, voltages written above the holes, all about the same:

Bad one, with one weak cell showing about 0.3V instead of 1.3V:

The other two bad sticks looked exactly the same. So that leaves me with what look like 17 good sticks and 3 bad ones:

What I really need to do now, is get the other pack out the car and do the same on those sticks, and get the third pack charged and cycled a few times so I can do the same on that one. In the meantime, I've also rigged up a capacity checker with a cheap Chinese eBay current and voltmeter. It's got a shunt so it can measure current and will log battery capacity. I've got it wired up on a good stick with an 8 Ohm resistor doing the discharging (about 1A when the stick is charged) to have a look at what it does:

Tidied up the rig a bit, checked it didn't explode or overheat and left it discharging overnight:


That suggests a remaining capacity of 6.4AH. Original sticks were supposedly 6.5AH so that looks pretty promising. I've now got one of the bad sticks discharging to see what it does. The starting voltage was about 0.1V down on the known bad cell. After about 1.4AH discharged from it, the bad cell was empty and showing a negative voltage while the others were still holding 1.26V. I'm not purporting to be an expert on this, but it’s looking like the ultimate bench test for these sticks is to charge them fully, leave them for at least a month to weed out the high self-discharge cells, then test them.

Tidied up the rig a bit, checked it didn't explode or overheat and left it discharging overnight:


That suggests a remaining capacity of 6.4AH. Original sticks were supposedly 6.5AH so that looks pretty promising. I've now got one of the bad sticks discharging to see what it does. The starting voltage was about 0.1V down on the known bad cell. After about 1.4AH discharged from it, the bad cell was empty and showing a negative voltage while the others were still holding 1.26V. I'm not purporting to be an expert on this, but it’s looking like the ultimate bench test for these sticks is to charge them fully, leave them for at least a month to weed out the high self-discharge cells, then test them.

I think whether you like it or not, it looks like you are

Agreed. Shockingly obvious.
 

i supose the next step would be to see if you can re-make a stick with all good  cells

Tidied up the rig a bit, checked it didn't explode or overheat and left it discharging overnight:


That suggests a remaining capacity of 6.4AH. Original sticks were supposedly 6.5AH so that looks pretty promising. I've now got one of the bad sticks discharging to see what it does. The starting voltage was about 0.1V down on the known bad cell. After about 1.4AH discharged from it, the bad cell was empty and showing a negative voltage while the others were still holding 1.26V. I'm not purporting to be an expert on this, but it’s looking like the ultimate bench test for these sticks is to charge them fully, leave them for at least a month to weed out the high self-discharge cells, then test them.

Tidied up the rig a bit, checked it didn't explode or overheat and left it discharging overnight:


That suggests a remaining capacity of 6.4AH. Original sticks were supposedly 6.5AH so that looks pretty promising. I've now got one of the bad sticks discharging to see what it does. The starting voltage was about 0.1V down on the known bad cell. After about 1.4AH discharged from it, the bad cell was empty and showing a negative voltage while the others were still holding 1.26V. I'm not purporting to be an expert on this, but it’s looking like the ultimate bench test for these sticks is to charge them fully, leave them for at least a month to weed out the high self-discharge cells, then test them.

Tidied up the rig a bit, checked it didn't explode or overheat and left it discharging overnight:


That suggests a remaining capacity of 6.4AH. Original sticks were supposedly 6.5AH so that looks pretty promising. I've now got one of the bad sticks discharging to see what it does. The starting voltage was about 0.1V down on the known bad cell. After about 1.4AH discharged from it, the bad cell was empty and showing a negative voltage while the others were still holding 1.26V. I'm not purporting to be an expert on this, but it’s looking like the ultimate bench test for these sticks is to charge them fully, leave them for at least a month to weed out the high self-discharge cells, then test them.

Tidied up the rig a bit, checked it didn't explode or overheat and left it discharging overnight:


That suggests a remaining capacity of 6.4AH. Original sticks were supposedly 6.5AH so that looks pretty promising. I've now got one of the bad sticks discharging to see what it does. The starting voltage was about 0.1V down on the known bad cell. After about 1.4AH discharged from it, the bad cell was empty and showing a negative voltage while the others were still holding 1.26V. I'm not purporting to be an expert on this, but it’s looking like the ultimate bench test for these sticks is to charge them fully, leave them for at least a month to weed out the high self-discharge cells, then test them.

Tidied up the rig a bit, checked it didn't explode or overheat and left it discharging overnight:


That suggests a remaining capacity of 6.4AH. Original sticks were supposedly 6.5AH so that looks pretty promising. I've now got one of the bad sticks discharging to see what it does. The starting voltage was about 0.1V down on the known bad cell. After about 1.4AH discharged from it, the bad cell was empty and showing a negative voltage while the others were still holding 1.26V. I'm not purporting to be an expert on this, but it’s looking like the ultimate bench test for these sticks is to charge them fully, leave them for at least a month to weed out the high self-discharge cells, then test them.

I had a look with the scope attached but it didn't actually tell me anything extra that was useful. Good stick followed by 'bad' stick:


I guess what it has told me is that the voltage drop when the load is connected is almost instantaneous, as it happens in about 5ms. I was expecting it to be slower than that. So having cleared that up, I tested all the sticks using the basic voltmeter method, making a note of the resting voltage and the voltage after 5 seconds with the load connected. That resulted in 17 sticks which were almost identical and 3 outliers which dropped more voltage. So what I did on the outliers was got a leather punch and made some small holes in the heatshrink so I could measure the voltage across the individual cells while they had a load attached. I did the same on a good stick so I had something to compare it to. It basically showed that the bad sticks had a single weak cell in them that was dropping a lot more voltage under load:
Good one, voltages written above the holes, all about the same:

Bad one, with one weak cell showing about 0.3V instead of 1.3V:

The other two bad sticks looked exactly the same. So that leaves me with what look like 17 good sticks and 3 bad ones:

What I really need to do now, is get the other pack out the car and do the same on those sticks, and get the third pack charged and cycled a few times so I can do the same on that one. In the meantime, I've also rigged up a capacity checker with a cheap Chinese eBay current and voltmeter. It's got a shunt so it can measure current and will log battery capacity. I've got it wired up on a good stick with an 8 Ohm resistor doing the discharging (about 1A when the stick is charged) to have a look at what it does:

I had a look with the scope attached but it didn't actually tell me anything extra that was useful. Good stick followed by 'bad' stick:


I guess what it has told me is that the voltage drop when the load is connected is almost instantaneous, as it happens in about 5ms. I was expecting it to be slower than that. So having cleared that up, I tested all the sticks using the basic voltmeter method, making a note of the resting voltage and the voltage after 5 seconds with the load connected. That resulted in 17 sticks which were almost identical and 3 outliers which dropped more voltage. So what I did on the outliers was got a leather punch and made some small holes in the heatshrink so I could measure the voltage across the individual cells while they had a load attached. I did the same on a good stick so I had something to compare it to. It basically showed that the bad sticks had a single weak cell in them that was dropping a lot more voltage under load:
Good one, voltages written above the holes, all about the same:

Bad one, with one weak cell showing about 0.3V instead of 1.3V:

The other two bad sticks looked exactly the same. So that leaves me with what look like 17 good sticks and 3 bad ones:

What I really need to do now, is get the other pack out the car and do the same on those sticks, and get the third pack charged and cycled a few times so I can do the same on that one. In the meantime, I've also rigged up a capacity checker with a cheap Chinese eBay current and voltmeter. It's got a shunt so it can measure current and will log battery capacity. I've got it wired up on a good stick with an 8 Ohm resistor doing the discharging (about 1A when the stick is charged) to have a look at what it does:

I had a look with the scope attached but it didn't actually tell me anything extra that was useful. Good stick followed by 'bad' stick:


I guess what it has told me is that the voltage drop when the load is connected is almost instantaneous, as it happens in about 5ms. I was expecting it to be slower than that. So having cleared that up, I tested all the sticks using the basic voltmeter method, making a note of the resting voltage and the voltage after 5 seconds with the load connected. That resulted in 17 sticks which were almost identical and 3 outliers which dropped more voltage. So what I did on the outliers was got a leather punch and made some small holes in the heatshrink so I could measure the voltage across the individual cells while they had a load attached. I did the same on a good stick so I had something to compare it to. It basically showed that the bad sticks had a single weak cell in them that was dropping a lot more voltage under load:
Good one, voltages written above the holes, all about the same:

Bad one, with one weak cell showing about 0.3V instead of 1.3V:

The other two bad sticks looked exactly the same. So that leaves me with what look like 17 good sticks and 3 bad ones:

What I really need to do now, is get the other pack out the car and do the same on those sticks, and get the third pack charged and cycled a few times so I can do the same on that one. In the meantime, I've also rigged up a capacity checker with a cheap Chinese eBay current and voltmeter. It's got a shunt so it can measure current and will log battery capacity. I've got it wired up on a good stick with an 8 Ohm resistor doing the discharging (about 1A when the stick is charged) to have a look at what it does:

I had a look with the scope attached but it didn't actually tell me anything extra that was useful. Good stick followed by 'bad' stick:


I guess what it has told me is that the voltage drop when the load is connected is almost instantaneous, as it happens in about 5ms. I was expecting it to be slower than that. So having cleared that up, I tested all the sticks using the basic voltmeter method, making a note of the resting voltage and the voltage after 5 seconds with the load connected. That resulted in 17 sticks which were almost identical and 3 outliers which dropped more voltage. So what I did on the outliers was got a leather punch and made some small holes in the heatshrink so I could measure the voltage across the individual cells while they had a load attached. I did the same on a good stick so I had something to compare it to. It basically showed that the bad sticks had a single weak cell in them that was dropping a lot more voltage under load:
Good one, voltages written above the holes, all about the same:

Bad one, with one weak cell showing about 0.3V instead of 1.3V:

The other two bad sticks looked exactly the same. So that leaves me with what look like 17 good sticks and 3 bad ones:

What I really need to do now, is get the other pack out the car and do the same on those sticks, and get the third pack charged and cycled a few times so I can do the same on that one. In the meantime, I've also rigged up a capacity checker with a cheap Chinese eBay current and voltmeter. It's got a shunt so it can measure current and will log battery capacity. I've got it wired up on a good stick with an 8 Ohm resistor doing the discharging (about 1A when the stick is charged) to have a look at what it does:

I had a look with the scope attached but it didn't actually tell me anything extra that was useful. Good stick followed by 'bad' stick:


I guess what it has told me is that the voltage drop when the load is connected is almost instantaneous, as it happens in about 5ms. I was expecting it to be slower than that. So having cleared that up, I tested all the sticks using the basic voltmeter method, making a note of the resting voltage and the voltage after 5 seconds with the load connected. That resulted in 17 sticks which were almost identical and 3 outliers which dropped more voltage. So what I did on the outliers was got a leather punch and made some small holes in the heatshrink so I could measure the voltage across the individual cells while they had a load attached. I did the same on a good stick so I had something to compare it to. It basically showed that the bad sticks had a single weak cell in them that was dropping a lot more voltage under load:
Good one, voltages written above the holes, all about the same:

Bad one, with one weak cell showing about 0.3V instead of 1.3V:

The other two bad sticks looked exactly the same. So that leaves me with what look like 17 good sticks and 3 bad ones:

What I really need to do now, is get the other pack out the car and do the same on those sticks, and get the third pack charged and cycled a few times so I can do the same on that one. In the meantime, I've also rigged up a capacity checker with a cheap Chinese eBay current and voltmeter. It's got a shunt so it can measure current and will log battery capacity. I've got it wired up on a good stick with an 8 Ohm resistor doing the discharging (about 1A when the stick is charged) to have a look at what it does:

I had a look with the scope attached but it didn't actually tell me anything extra that was useful. Good stick followed by 'bad' stick:


I guess what it has told me is that the voltage drop when the load is connected is almost instantaneous, as it happens in about 5ms. I was expecting it to be slower than that. So having cleared that up, I tested all the sticks using the basic voltmeter method, making a note of the resting voltage and the voltage after 5 seconds with the load connected. That resulted in 17 sticks which were almost identical and 3 outliers which dropped more voltage. So what I did on the outliers was got a leather punch and made some small holes in the heatshrink so I could measure the voltage across the individual cells while they had a load attached. I did the same on a good stick so I had something to compare it to. It basically showed that the bad sticks had a single weak cell in them that was dropping a lot more voltage under load:
Good one, voltages written above the holes, all about the same:

Bad one, with one weak cell showing about 0.3V instead of 1.3V:

The other two bad sticks looked exactly the same. So that leaves me with what look like 17 good sticks and 3 bad ones:

What I really need to do now, is get the other pack out the car and do the same on those sticks, and get the third pack charged and cycled a few times so I can do the same on that one. In the meantime, I've also rigged up a capacity checker with a cheap Chinese eBay current and voltmeter. It's got a shunt so it can measure current and will log battery capacity. I've got it wired up on a good stick with an 8 Ohm resistor doing the discharging (about 1A when the stick is charged) to have a look at what it does:

Lunchtime shens. I soldered up the resistors and connected the solenoid up to my 12V supply so I could trigger it manually and have a look at what the battery sticks do. Started with an 8 Ohm resistor because not much can go wrong there and then added in the 1 Ohm ones one by one as I got braver. So with all five 1 Ohm resistors in parallel, that's 0.2 Ohms, which is about 40A at 8V and 35A at 7V depending on the state of charge. Just for reference, the car commands about 10A for cranking and 35-40A at around 50% hybrid assist when driving.
This stick was sitting around 7.7V resting voltage, and pulled down to 7V with the full load attached:

Emergency snips on hand in case anything bad happens. Snip through that thick red wire on the left.
The voltage actually settled after a few seconds so I don’t think I’ll need to bother with the Arduino. I think I'm just interested to see what it drops to under heavy load, to see if there are any weak cells and I'm pretty sure this will tell me what I need to know. It’ll be pretty obvious which sticks have a weak or bad cell in them because the voltage will drop further.
I actually brought two sticks in to play with and, based on the above, it looks like I might have one good one and one bad one on the bench. MUCH EXCITE. 'Bad' stick was 7.3V resting and 5.2V under load - a much bigger drop. However, I do need to repeat this after a full charge because these Insight sticks haven’t been charged since July and are probably a bit self-discharged. Then I can rattle through these of a lunchtime. Takes very little time per stick, but there are 60 of them to do!

Right then, got pretty much everything I need. Essentially what I was planning to do was just take a voltage reading, manually trigger the solenoid and take another voltage reading after 5-6 seconds. This would be perfectly adequate, but I decided to complicate things a little by adding some Arduino control. I can get the Arduino to automatically trigger the solenoid and read/log the voltage for 5-6 seconds, then disconnect it again. So below I’ve got:

Spare bit of aluminium extrusion construction kit stuff, two Insight sticks, bag of high current M8 ring terminals, Arduino UNO, 4x relay board for the Arduino, bag of 100W 1R resistors, and a 1970s Triumph starter solenoid. Well spotted @captain_70s
Quick mock-up with some bolts and washers and T-slot nuts for the extrusion stuff and it’s going to look something like this:

The Arduino will be controlling the board with 4x relays. Will get one of those relays to switch on the starter solenoid from a 12V supply. It pulls about 3A at 12V DC so it’s probably going to need a flywheel diode across the solenoid coil to protect the relay. Relay is rated to 10A at 30V DC but my experience is switching DC tends to make those sorts of relays stick. I found some 1N5401 diodes in my stash at work which are pretty big. They ought to handle anything the coil spits back out. 
So then the Arduino reads the voltage. It only reads up to 5V and the stick voltage is 8-9V depending on state of charge, so I’ll put it on a 10k potential divider with a 50/50 split. My pal also suggested I put a 5V Zener diode across the Arduino to protect it from getting fried when the solenoid disconnects the batteries. I had another root in my stash and found some 1N5338B Zeners which are 5.1V. Voltage reading range will be up to around 4.2V so they’re ideal. 
I am of course wondering if I’m over-complicating things. It’s not too late to back out of this and just do it manually…

I thought it was originally about the stuff piled on the roof rack (vintage suitcases, oil drum, random old tyre, bmx, hay bale etc) from that era of modded VWs in the 00s, but it has evolved to refer to the look as a whole (lowered, camber, poke & stretch, roof rack + pineapple additions, sticker bomb, 1 rusty wing, fake patina, whiff of Ankor wax etc etc. 

I thought it was originally about the stuff piled on the roof rack (vintage suitcases, oil drum, random old tyre, bmx, hay bale etc) from that era of modded VWs in the 00s, but it has evolved to refer to the look as a whole (lowered, camber, poke & stretch, roof rack + pineapple additions, sticker bomb, 1 rusty wing, fake patina, whiff of Ankor wax etc etc.