Trying to trick charger

Trying to trick charger to stay in desulfate mode longer by using a small test light. So far it's working. The voltmeter is measuring 30 volts AC. Trying to bring 6 year old back from the dead. So far after 6 drsulfating cycles it back to 390 amps.

Some of these portable jump starters will not work if battery is to low ( almost dead) but if you put a battery charger on battery and hook up jump starter it will work.

All this experimenting with battery's is interesting. I suppose you have never had one blow up on you. I've been right next to one that did. Very loud and scary. My battery guy said sometimes it can happen when charging if it has a short inside.

Speaking from experience, never place your head in a position that it is anywhere near right over the top of the battery. I was charging a 6 volt in a Ford tractor once and had the little screw tops off where the acid is. The alligator clamps sparked when I plugged in the charger and the battery blew up right in my face. Not a pretty sight!

Mike,
I've seen my share of batteries blow. When they blow when there is a hydrogen cloud around them. The battery that blew left only the lead plates behind. We were using a very large charger on battery trying to get brothers car started in cold winter. When I hit the key, boom, big flash, nothing left but acid dripping all over the place, bubbling on concrete floor. Good thing my brother and I were both inside the car, or someone may have lost eyes.

What you don't realize is my batteryminder 12248 has never boiled a battery. There are no gas bubbles in electrolyte during charging or desulfating. It hard to understand how 30vac is being used to desulfate and not overcharge.

Just checked, bulb is keeping charger in desulfate mode, amps are up to 395. Not bad for a 2011 battery. I never gave thought there was any hope for this battery. Time will be the final test to see if battery can hold a charge with out life support.

Learned two things, never charge and desulfate two batteries at the same time. And how to trick charger to stay in desulfate mode longer. Plan to keep an eye on progress. Perhaps remove bulb at night and let charger go into equalization and float charge mode before desulfating tomorrow.
geo

Amen to that.
We had a 977 cat that had an 8d batt. under the seat, used to start it with a welder, one day hit the starter, boom, lifted me up and my head hit the roof!!

One way to stop sparks is put hot clap on and make sure it making good connection and then put ground to frame of what ever your charging so if it sparks it not at the battery.

A charger or jumper cables don't need to be hooked up to a battery to make the battery blow up. I've seen batteries blow up when the engine is cranked over. This happens due to a loose connection at the battery post causing a spark. The fluid in a battery will blind you instantly if it gets directly in your eyes. So the choice is yours if you wear goggles or a face shield or not. I tell my son this all the time to be careful when working around batteries.

A battery blows up when a spark ignites the gasses given off when sulfuric acid is added to the lead in the battery; thus lead sulfate (pbso4) plus hydrogen gas is the chemical reaction. The hydrogen gas is the volatile part!

"It hard to understand how 30vac is being used to desulfate and not overcharge."

I would assume the frequency is 60 Hz, power line frequency. Average value of AC is zero. Hence zero charge. You just rattle the plates and shake off the scale is my guess. 30v gives them a good smack and then a reverse smack etc.

Back to what I said about low amperage/life span (aka cheap) batteries....short plates; lots of space at the bottom to collect scale without shorting out plates. My guess....never did what you are doing but I do know about the scale pile and plate length.

(quoted from post at 10:12:09 01/12/17)

Learned two things, never charge and desulfate two batteries at the same time. And how to trick charger to stay in desulfate mode longer. Plan to keep an eye on progress. Perhaps remove bulb at night and let charger go into equalization and float charge mode before desulfating tomorrow.
geo

Click to expand...

Can you explain how you trick your BatteryMinder to stay in desulfate mode, or show a picture?

Hydrogen gas is given off by ANY lead/acid battery during both charging and discharging (as in being used). It is produced by a chemical reaction that stores the electrical energy in the battery. That is the reason batteries are vented. Hydrogen is a result of the process of charging and discharging. Also, batteries do not necessarily "boil" but rather give off hydrogen more rapidly during some conditions such as a shorted cell, overcharging, or excessively rapid discharging.
It makes no difference which clamp is attached first. A spark is a spark whether it comes off the positive or the negative post.

Somewhere years ago I read about jumping a car where the return line was connected via bumper to bumper contact AFTER the POS lead was attached. I never paid much attention but not too many years ago the subject of remove the net first when removing/installing a battery. Finally dawned on me if you are installing the + lead and accidentally get your wrench against something grounded and metallic, it won't blow the battery/melt the wrench. Made since and have been following the advice since.