Tag Archives: rejuvenation

2.5A12-EX Rejuvenated Battery Sat in Subfreezing temps for months – started right up!

The Tesla Chargers 2.5A12-EX battery is still being planned for release soon.

Here is a short video I took of my 1977 Datsun 620 pickup that sat for months in subfreezing temperatures.

The battery was already around 7+ years old and was dead before the 2.5A12-EX rejuvenated it.

That rejuvenated battery sat in these temps all this time and started this truck right up with full cranking ability. That would be hard for even some new batteries in these conditions but it was not a problem for the old rejuvenated battery.

Learn more: https://teslachargers.com/products/battery-chargers-rejuvenators/2-5-amp-12-volt-lead-acid-battery-charger-rejuvenator-120-240-volts/

Join the notification in the right column to learn when this miracle charger will be available again – coming soon!!!


Free Download – Tesla Chargers Book

Here is a new book that is a compilation of the instruction manuals for all the Tesla Chargers and Solar Charge Controllers. There is also some information about the basics of battery charging and rejuvenation.

It is a 71 page PDF: Tesla Chargers Manual

15-20% off Chargers/Rejuvenators & Solar Charge Controllers



All Solar Charge Controllers are now the EX (Extreme) version, which utilizes John Bedini’s new proprietary SCR switching method and have been measured up to 99.8% efficient. They deliver more to the battery from the solar panels than any other solar charge controller in the world. On the solar charge controller product pages, it may not list these units as EX models, but they are all EX models this is what has been shipping for the last few weeks.

1AU Universal Battery Charger
2A12 2 Amp 12 Volt Charger/Rejuvenator
10A12 10 Amp 12 Volt Charger/Rejuvenator
25 Amp 12 Volt Charger/Rejuvenator

S40A12/24-EX (Extreme Model)
S80A12/24-EX (Extreme Model)
S160A12/24-EX (Extreme Model)


S10A12-EX & S20A12-EX (Extreme Model)


Why do Lead Acid Batteries go Bad?

Lead Acid Batteries

The reason that lead acid batteries go bad is because every battery charger on the market, except for Tesla Chargers, chronically under chargers the battery. A lead acid battery actually needs to be pushed to 15.1-15.3 in order to fully remove the final layers of sulfation.

Lead Acid Batteries
Lead Acid Battery

Most chargers cut off from14.3 to 14.8 for lead acid batteries such as your car battery. A fully charged lead acid battery is 12.6 volts so when they push it to that range and the voltage settles at 12.6 or above, they try to convince you that the battery is fully charged. But the voltage can still sit there even if the full capacity of the lead acid batteries isn’t actually there.

Many self-proclaimed experts will tell you that you can just increase the current (amperage) and boil the lead acid batteries a bit to get it back into shape. However, that is a scam because removing the sulfation on the lead plates is a VOLTAGE event and NOT a current event.

If the voltage is not high enough (15.1~15.3), you can boil lead acid batteries for a week straight and no more sulfation will be dissolved back into solution.

And, with the conventional circuits that other companies use, they don’t know how to bring the lead acid batteries to the proper voltages for full desulfation without boiling them to death. Of course, the heat damages the lead acid batteries by warping the plates, etc…

Tesla Chargers circuits are made by John Bedini, the world’s recognized master of lead acid battery charging and rejuvenation. The circuits he has invented actually bring the lead acid batteries to the full “topping event” where the batteries are fully charged and rejuvenated.

Actually, these circuits can fully rebuild the chemistry of lead acid batteries to like-new on each charge/discharge cycle. How? The chemistry involved in discharging a battery is 100% reversible; this can give a theoretical INFINITE number of cycles to lead acid batteries.

This is the most important graph in the history of lead acid batteries. And, it is about 100 years old! This has been known for a century, but the manufacturers of lead acid batteries of course have neglected to tell you this.

Voltage Changes During Charge
Voltage Changes During Charge

As the voltage goes up, it comes to a peak and when the final layers of sulfation are removed in the range a bit over 15 volts, you see the voltage drop.

Why does the voltage drop if it is fully charged instead of going up? Because the sulfation presents an impedance and that causes the voltage to rise like back pressure against a gas. When the final layer of sulfation is removed and dissolved back into solution, that electrolyte becomes more conductive, impedance drops, and the voltage goes down.

That is the ‘TOPPING EVENT‘ that is necessary to 100% fully reverse the chemical changes caused by the discharge of lead acid batteries.

That chart above is about 100 years old from a book we called the “Battery Bible” (not its real name). It was a manual teaching farmers a century ago how tokeep their lead acid batteries indefinitely good. That chart shows 2.6 volts per cell or 15.6 to reach the topping event but about $2 million in research at John Bedini’s company showed us that 15.1~15.3 is actually what was giving us the topping event in all the modern lead acid batteries that were tested.

If it is a gel cell or AMG type lead acid, then 14.8 is the highest you want to go. Otherwise, the gel can get dried out prematurely. And 14.8 is also the same max voltage to push the new LiFePO4 batteries to. Those are lithium iron phosphates and not the typical “lithium ions”, which are really lithium cobalt batteries. We actually have a few solar charge controllers specific for LiFePO4’s which would work perfect for gels or AMG’s.

Tesla Chargers products are based on decades of lab tests by John Bedini and most specifically in the early 2000’s. The most up to date line that we have are better than ever and these products have saved literally hundreds to thousands of tons of batteries from the scrap yard since 2006 when Tesla Chargers first launched.

Learn more at https://teslachargers.com/

Aaron Murakami
Tesla Chargers

p.s. If you haven’t seen our new Facebook page, please visit this link and give us a like! https://www.facebook.com/pages/Tesla-Chargers/1606880942878063

Tesla Chargers’ new homepage!

Welcome to the new homepage – we just converted our website to a WordPress site to make it easier to maintain, increase the ease of navigation and make it easier for you to post comments, questions or concerns right on this site using the DISQUS comment system.

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Take a look around and let us know if you have any questions.