You can make this device yourself using recycled materials and restore lead acid batteries. This works for car batteries, truck batteries, deep cycle and solar batteries. Basically any lead acid battery that is sulfated and losing power can be restored using this device.
I have read that you can have some success on rechargeable flashlight batteries as well but I have never tried it yet. You can not charge lithium batteries with this though because of the built in charging circuits in the batteries.
I am going to guide you step by step through the process of building your own batter rejuvenator. This is a pulse motor which sends pulses of high voltage spikes into a battery, breaking up the crystals which reduce the battery life and available energy.
This device tunes itself somewhat to your battery as it charges. You can notice the difference in motor run speed with different sized batteries.
This first article covers the parts list.
I will give you a list of parts and their sources. Again, you can build one for free if you can salvage the parts yourself.
I am doing this for fun and not for profit. I simply want to share the information.
Here is the parts list and circuit:
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