Lead Acid Battery Charging Stages

How does a battery charger or charge controller recharge a lead acid battery? Here is the simple explanation.

In this video, I will describe the 3 stages of charging a lead acid battery as well as the equalization process. We get spoiled by advanced battery chargers nowadays but it still very beneficial to understand how it works and how to tweak the settings of your charger based upon the specific recommendations of the manufacturer.

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[linksmith]

Excelent information. I worked at a Batteries+Bulbs for a few years and the amount of miss-information about lead acid chemistry batteries is fantastic.

 Here are some more basics:
There are two categories of Lead Acid batteries in three different form factors. Wet cell (Regular Flooded batteries) and Dry cells (Gel and AGM batteries). Gels will never be used to start an engine because they don't work under 32 degrees F while AGM and flooded cells do.

There are three different construction types for Flooded and AGM batteries, SLI (Starting, Lighting, Ignition) used to provide huge currents for short bursts, Dual Purpose which can start engines and run high demand electronics like powerful stereos, and Deep Cycles which are used for things like electric motors like golf carts, solar systems, RVs, etc. Gel batteries all fall into the Deep Cycle category.

AGM batteries and Flooded cells both use the same style of charging routine. Gel Cells however require typically lower amperage charging schemes.

Desulfating chargers work usually by widely fluctuating voltage, frequency, and amperage.

Slower charging speeds is typically better for the battery. The less energy you can impart to the fluid (in the form of heat) the better. As it gets hotter, you'll suffer evaporation and sulfation (as the sulfur in the acid gets more concentrated). Both evaporation and sulfation limit battery output amperage and overall capacity. Evaporation can mean parts of the plates are not in acid and therefore aren't producing power. Sulfation is when sulfur suspended in the acid builds up on plates preventing reaction from taking place.

Frozen batteries can sometimes be recovered if you use the dumbest charging scheme possible (I mean dumbest in reference to the charger). I've recovered batteries that were at 0V first by putting them on a 55 amp "dumb" charger (meaning it output power whether there was a battery or not even plugged into it, so don't short the clamps or you'll get a huge spark and loud bang). Once it reached a relatively acceptable state (usually around 10 volts), I would then plug it into a smart, desulfating charger. Ours was a brand called Granite and saved my ass multiple times, it's a great charger.

Maximum recommended charge voltage for a wet cell is usually around 14.2 volts, and for AGM 14.4 volts. Going a volt or two above this usually won't hurt a battery much if it's for a short period of time. A preferred float voltage is around 13.5 volts.

[barrybarry]

Great video. Liked the way you ended it. ‘Keep it civil’. Thanks for the insight and really good job

[haihai]

The best closing i've ever seen on youtube. Great video.

[dirtracer]

??? i feel like im missing something.. u said around or a little after 2:30, that we can use a hydrometer to measure specific gravity, but theyre hard to use so most ppl use voltage how do u use voltage to get an approximate specific gravity?? it seems like u would have to physically test it, otherwise to get gravity youd have to have other metrics to work with.. right??

[tonychahine]

What if i have 2 strings of 4x230ah 48 v power bank ..is it enough to adjust the charging current to 40 amps?

[robsdeviceunknown]

Yeah this was a good video. This made me realize that my old cheap battery charger is insufficient. I would love to see deep cycle maintenance etc. Since most of what I use for prepping and solar power is deep cycle.

[lawrencedavidson]

Very good video. I am currently using sealed lead acid batteries in my small solar power system. My Rich Solar 20 amp MPPT charge controller seems to be very good at providing all the different stages of charging as mentioned in the video. So it seems i have nothing to worry about as i don't discharge them below 12.3V and they are slowly, fully recharged every day by mid afternoon. Thanks and greetings from sunny Jamaica.

[robertd]

Excellent video! Just the basics is what I was looking for. Thanks!

[Largeportion]

Well done, informative without rabbiting on with a stream of flowing shit, thank you.

[jec_ecart]

Perfectly summed up. In India where temps go up 42 or 45.c I follow 14.1V summers and 14.4v winters. Bulk.

[vikingdane]

Trying to charge a 12v 3AH/C20 sealed lead battery on my Thunder smart charger. Batt voltage is "Too Low" at 10 volts and not allowed to charge. How can I get this into charging range or is it junk?

[snardylarose]

Is the bulk charging provide enough charge to the battery?

[RayMerrell]

Is float charging the same as trickle charging?

[Skynet]

12v 230ah c20 battery charging settings ?

[USL.Website]

Hi sir, I have the following on my Solar Charge Controler:
Absorption, Floating, Equalization and Constant pressure stages on my controller, what I don't understand is that Absorption & Equalization can be set to run for a number of hours.
How many hours to set Absorption & Equalization at? At Default, it was set to 2 hrs but I brought it down to 1 hrs each, please assist if you can Sir? I also don't understand what to set the voltages at: I have Absorption 14.7V, Floating 13.5V, Equalization 14.4V and Constant pressure at 14.4V, my battery is 12V deep-cycle 120AH Lead-Acid, if you could offer me any advice please sir?

[markflack]

Nice video, very well explained. thank you.

[ri]

I am using a buck converter to charge my 165ah lead acid battery 12v and it supplies constant voltage and almost constant current (as it is connected to a solar panel) so, will charging the whole battery with constant voltage and variable current affect my battery's life?

[bytetronics]

Hi, i need your help..i have a 4v 500mah sealed lead acid battery. Can i charge that with 5.3 v 500 mah ordinary charger..And if i can then how long it will take to charge the battery fully.

[RedPillDosage]

I'm so sad that my C-tek pooped out on me. I loved that charger. Now it's just back to my Imax B6. Still gets the job done but got a better sense of relief with the C-tek

[globalsydney]

Fahrenheit to Celsius conversion 120f =48.8c, 100f=37.7c