I recently picked up an old drone display from work, it featured a rechargeable video playback showing what the drones can do. We have long since sold those specific drones and we’ve been hanging onto the display for years. After acquiring it while cleaning out the stockroom, I took the video portion home in the hopes that maybe I could use it for something. Sadly, the video is flashed into memory on the board with no way for me to add anything new, however, upon opening the cardboard case it was in, I found this whopping Lithium battery inside.
Instantly my mind began racing with ideas, but I only know the basics of electronics, let along Lithium batteries. I do know they need a BMS in order for them to charge properly and thought I would need to ask about how to do that (though, searches on Youtube could remedy that as well), but I realized the battery has a board attached to it and I’ve seen other BMS boards that look very similar.
So my first question is if that is what I’m seeing on the end of the battery?
What kind of uses could this size battery be used for? I’m thinking along the lines of phone chargers or just general power banks for various things.
What type of charger is recommended if this is ready to go and what types of connectors should I have? I could, in theory, just use the existing board for the LCD and charge it through that, but I’m thinking that might be more hassle than its worth.
Below are the pics of the battery itself:
The included board on the battery
The battery itself
The video player, the LCD is mounted behind the large sheet of metal the board is laying on.
First of all, you posted big pictures without any sort of adjustment or resizing. This wreacks havoc in the forum page layout, namely for mobile devices. Please edit your post and fix it, just use the following code instead (adjusted for 720 pixels of width, can also use just {width:100%} instead):
Concerning your question, the circuit you see is a basic low power battery management system with just a single dual 8205A MOSFET switch. The BMS does nothing with regards to charging. Its role is to shut off battery power once certain voltage or current thresholds have been reached: undervoltage, overvoltage and overcurrent. The most important is the undervoltage one, prevents the cell from being over-discharged. The overcurrent protection figure is a function of MOSFET current/power handling (in this case with a single 8205A it will trip a bit above 5A, this depends on sense voltage and MOSFET resistance). Lastly, the overvoltage protection is there but is generally set laxly at ≈4.3V, this is very high voltage already and if your charger is repeatedly allowing cell voltage to raise that much battery life will suffer seriously.
Charging must be managed by an external charging circuitry or standalone charger with CC/CV (constant current and constant voltage profile) plus current tapering cut-off if unmanned (automatic cut-off can be dismissed if there's someone to disconnect or remove the cell from the charger).
Easy cell to charge seeing as its only a single cell that is 3.7v so no balance system is needed any standard lithium charger can charge it. The capacity is big so at 1amp it would take over 8 hours from scratch to fully charge.
Uses can vary i guess. You could save it and enter this scratch build contest on here If you do make a battery bank you will need a boost driver on the output to achieve the 5v the USB port needs.
Id personally whack it in my digital radio as it came with a 3.7v lithium but its only 800mah so this cell would give me 10 times the run time lol. Ive been after a similiar cell for a while.
You can use a charging board like this TP4056 Micro USB Charger Module 5V 1A that will do the trick.
Remaining battery capacity can vary and is dependent on abuse and cycling levels.
LoL yes the TP4056 is a über-cheap way to manage charging for li-ion cells, just 5V input required from suitable smartphone/tablet “charger” or power supply:
The included board on the battery
The battery itself
The video player, the LCD is mounted behind the large sheet of metal the board is laying on.
If you do make a battery bank you will need a boost driver on the output to achieve the 5v the USB port needs.