Post Mortem of a Lithium Jump Starter.

Introduction: Post Mortem of a Lithium Jump Starter.

Last week the maxmade lithium jump starter for my wife had stopped working. No more charging of cell phones and the output voltage on the jump start cable was around 8.3v compared to 11.4v originally. I suspected a faulty cell and as part of a bet with my wife, I opened up this device to prove my Point.

Step 1: Opening by Force!

There are no screws in this jump starter. Using my pen knife I set to work, while at work!

Before the jump starter quit working, there was a rattle inside of it. Apparently piece of a ferrite choke get broken and made the rattling. I am not sure if these pieces caused a fault internally.

Step 2: Checking Out the Insides.

What we have inside is a lithium iron phosphate pouch cell battery (actually 3 cells in series) and a circuit board for charging, balancing and bucking to 5volt. Also a high power led is part of the package for providing light.

Step 3: Investigation and Salvaging.

OK here is the pouch cell battery. Taking off the wrapping shows a damaged cell caused most likely by heat or manufacturer defect. These cells are lithium polymer and are not rated for high current use. If they were lithium iron phosphate then definitely they would last as a jump starter battery.

As a result of this post mortem, I have an extra led to play with now!

So, the bet is won and I'm looking forward to wifey jobs.

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    Rolf G
    Rolf G

    6 years ago

    Nice to come across to your able. I have the same problem and I can share some points that might interest you.

    1. I opened the case slowly by inserting knife between covers and carefully pop it out because this cover are locked from inside. But it looks too late in your case.

    2. You can replace the faulty battery from Note 4. It has the same thickness and width but shorter in length. Just solder the + and - with ample stranded wire size carefully for they are almost close to each other.

    3. Removing the old battery, you need a higher soldering iron wattage. Use solder sucker and avoid tapping the device to the table to drop the liquid solder lead. It might reach your eyes or skin.

    I was impressed by the number of able you have shared to our valued reader and enthusiast.