Professional VW van travelers experience solar battery fire while away...

This couple spent a few years traveling by van from Chile to the Prudhoe Bay, Alaska. While spending months away from the van, due to expired Visa, the lithium battery caught fire. The interior of the van was almost destroyed.
Well done little amateur travel videos and 15 of them. Seems they lived off of Patreon donations from those who "lived the dream" vicariously. I am amazed when a couple is able to pull that off. Many try, no idea how many succeed.
Wondering what probably caused the battery fire? Rodents caused a wiring short maybe? Rogue battery overcharged? CC malfunctioned? What say you?

Well done little amateur travel videos and 15 of them. Seems they lived off of Patreon donations from those who "lived the dream" vicariously. I am amazed when a couple is able to pull that off. Many try, no idea how many succeed.
Wondering what probably caused the battery fire? Rodents caused a wiring short maybe? Rogue battery overcharged? CC malfunctioned? What say you?

First Bank:16 180 watt Grape Solar with FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
Comments
I had a 73 transporter with the 67 hp pancake motor, It was a bit under powered, at the same time I had a Yamaha XS750 Motorcycle that had more horsepower. Can't imagine tackling the Al-Can hwy.
Nothing to do with solar in the video, but thanks, @softdown for the trip down memory lane!
I am available for custom hardware/firmware development
I love these videos. Turns out he saved money during his earlier job in IT. Was able to travel on just $10-15/day! Amazing.
His voice inflection really never changes. Even when he describes watching an acquaintance getting shot and killed in front of his van. The Argentine police had an issue with the guy that he does not describe.
I can't see any evidence of a BMS. It was also being charged via the solar panel while it was sitting for a long period of time.
These factors added together make it a recipe for a disaster.
Firstly, the fact that they are used cells probably from different computers, from different manufacturers and different ages and usage history means that they are more likely to go out of balance over time.
Secondly the fact that it was being charged on a daily basis via the solar panels probably without any loads on it would mean that the battery was at a high SOC most of the time which would have made the balance problems even worse.
Assuming the problem was not caused by an external or battery wiring short or a fault in the solar controller I think it is likely that the battery slowly went out balance over the months it was left standing on charge which would have meant the voltage on some of the cells would have risen to dangerous levels which would have raised the temperature of those cells to the point where they caught fire.
If the battery had a BMS it would have stopped it being charged when it had gone too far out of balance and/or kept the battery in balance. Alternatively if the battery had been disconnected from any loads and the solar controller it would have been OK.
To me this is more evidence supporting the importance of having a BMS. There are billions of computers, power tools and other devices in use which use the most dangerous lithium ion batteries. The reason that these devices work safely and don't catch fire is that all these devices have a BMS of some sort keeping the battery safe.
Simon
32x90Ah Winston cells 2p16s (48V), MPP Solar PIP5048MS 5kW Inverter/80A MPPT controller/60A charger, 1900W of Solar Panels
modified BMS based on TI bq769x0 cell monitors.
Homemade overall system monitoring and power management https://github.com/simat/BatteryMonitor
Just look at the "quality" of the solder joints and the different coloured batteries. If you get the same type of battery from the same manufacturer the will all be the same colour.
Simon
32x90Ah Winston cells 2p16s (48V), MPP Solar PIP5048MS 5kW Inverter/80A MPPT controller/60A charger, 1900W of Solar Panels
modified BMS based on TI bq769x0 cell monitors.
Homemade overall system monitoring and power management https://github.com/simat/BatteryMonitor
Why did the 1.6 liter air cooled engine need constant work? He was transporting six adventurers...with all of their accessories....up and down the Andes mountains. The gear was hauled in huge wooded boxes sitting on top of the van. A disaster waiting to happen.
Another really bright guy doing a pretty dumb thing....in retrospect.