Once again I will look at refining one of the pulse charger designs. This is just theory for now, I hope to have a working circuit up reasonably soon.
Essentially the goal is to make the pulse charger in a way that cycles off for a period of time and then back on, in a continuous manner. This will hopefully overcome the issues of diffusion (lack of it within the cell as it is charging) and gas liberation which usually causes the failures of the cells which manifests itself as leaking, excess heating or breached seals.
Even though the initial “Reverse Current” Charger dates back to the later 1950’s, the batteries made back then were predominantly of the “Carbon/Zinc” manufacture, which is still around today however the outer Zinc jacket is made so thin, there are holes in the Zinc by the time you purchase them. Ir was this type the orginal charger was made for. The fact it works very well for Nickel Cadmium and Nickel Metal Hydride cells as well as Lead Acid cells keeps it a timely circuit.
Alkaline cells, Mercury cells (few available), Lithium Ion and Silver/oxide cells do not take the reverse pulse well at all. The Alkaline cells being the focus of the pending charger is the goal. The Alkaline charger that is discussed here and in the other blog does work to a limited extent. The modification will be the addition of a main timer circuit to essentially shut the charger off in a cyclic manner to allow for normal difusion of material within the cell to occur.
Other chargers have been attempted for charging “Primary” Alkaline cells, but they too suffered various limitations, from undercharging the cell so it had minimal capacity, or they suffered from the same failures from heat of the “Alkaline Charger”- Namely leakage and small explosions. This is usually the result of a lack of diffusion and localized heating within the cells. The cycling will hopefully address this issue so effective charging will occur.
At the moment, with this just a theoretical excercise I do not have a circuit to add at the moment, but I will try get something up soon. I have a massive reconstruction project which will launch it’s own blog and videos so I cannot guarantee timelines.
The main blog.
The tangential blog.
The passive solar blog- outgrowth from some projects of mine.