I have a motorized garage door, and in the last years I'm having issues with the 12v lead acid battery that came with the kit. The battery outputs only 0,5A in short circuit and the voltage drops to less than 8V when the door tries to open. It opens 1 time and them the battery is dead, not having a chance to close the door.
Ofcourse the battery is only used when the grid is out of power, but when I need it's anoying to have the door open until the grid has power.
I already have a bunch of 18650 from my last salvage laptop batteries and I wanted to reuse them. My problem is charging the batteries. I saw that the open circuit voltage of the door opener charger is about 13.8v. And for 18650 3s pack is too much and for 4s is too little.
So, I thought on having a seperate 12,2/12,4v charger connected to the batteries and soldering an diode in one of the terminals of the battery in the garage door opener...
My question is: Is this enough to charge and when I need the batteries they are charged with no problems? Or the 2 chargers would conflict being one 13,8 having a diode stopping from charging the battery and another one at 12,2v charging the battery?
Ofcourse the battery is only used when the grid is out of power, but when I need it's anoying to have the door open until the grid has power.
I already have a bunch of 18650 from my last salvage laptop batteries and I wanted to reuse them. My problem is charging the batteries. I saw that the open circuit voltage of the door opener charger is about 13.8v. And for 18650 3s pack is too much and for 4s is too little.
So, I thought on having a seperate 12,2/12,4v charger connected to the batteries and soldering an diode in one of the terminals of the battery in the garage door opener...
My question is: Is this enough to charge and when I need the batteries they are charged with no problems? Or the 2 chargers would conflict being one 13,8 having a diode stopping from charging the battery and another one at 12,2v charging the battery?