Just a note of warning if you use these things. Make sure you can quickly remove it once it's connected. This exploded into flames this morning with my son's car fortunately without damage.
These devices are an accident waiting to happen. I am no expert, but my understanding is that if one cell in a number of lithium batteries connected in series fails through age, then it can become charged with reverse polarity, which can cause extreme heat.
I experienced a similar problem when I was trying to construct a battery pack for my pre-war bicycle which could be re-charged from the Sturmey-Archer Dynohub (with the addition of a little circuit board to do the rectification and voltage regulation) so that I could have decent lights on the bike.
I used two of the batteries normally sold for vaping devices (18650) connected in series. One of the batteries had a low voltage when it was delivered, but I thought nothing of it. I tried out the whole battery/circuit board assembly by connecting to a normal 6 volt battery charger for a few minutes, in lieu of the Dynohub. One of the lithium batteries must have been faulty and the whole battery pack melted on the bench, almost causing a fire! The circuit board was undamaged and I was able to use a different type of rechargeable battery with complete success.
I assume that one of the cells in your son's booster pack must have been faulty and that cell developed reverse polarity when he connected it to the car's battery. The Forum's resident electrical experts might be able to add more information.
Forum Locked
Topic Locked
Posted - 07/01/2022 : 09:30:39
