Batteries in electric vehicles

I use a Battery desulfator for my car, deep cycle boat and solar panels Batteries to electrically shake the sulfate crystals that build up on the lead plates. They last three times as long as the battery without the desulfator.

The National Renewable Energy Laboratory (NREL)
has been working with Recombination Technologies
and Optima Batteries to develop a current interrupt
charging algorithm to extend the deep life cycle of
valve-regulated lead-acid (VRLA) batteries. The work
in this area is based on the hypothesis that VRLA batteries
reach end-of-life prematurely with “normal”
constant current/voltage charge. Using a current interrupt
technique, NREL and Optima Batteries improved
the cycle life of VRLA modules from 150–200 deep discharge
cycles to 700 deep discharge cycles. This simple
technique is considered a “breakthrough” for use of
VRLA batteries in electric vehicles.

We used to call it assymetric AC or biased AC. The trick: put a resistor in series and a resistor parallel to a rectifier charging. It even worked for dry cells.

It worked great for lead acid. It corroded even leak proof dry cells so they would leak after 4 times recharging. With Ni-Cd it grew crystals that would either short the cell finally or even stab holes into them. So for lead acid ok but I would not risk it on LiPo.

I must have been 15 when I have seen it. I got my hamradio license when I was 17 and we have been using it some 5 years until we agreed it shortened useful life of our cells. Of coarse today they know how much, how often and how not to ruin cells

Still it is lead acid only, not LiPo.