Lead Acid Car Battery

You have the honor of watching a short developing..........

On Friday, April 26, 2019 at 12:33:52 PM UTC-4, snipped-for-privacy@gmail.com wrot e:

nd it was down to zip voltage. I put a power supply on it and ran up the v oltage until the current was at 2 amps. As I watched the battery voltage d ropped and the current rose! I double checked all the polarities and it's wired up right and the ground on the vehicle is disconnected.

se I dialed the voltage back, lather, rinse, repeat. It is now down to 2.5 volts and the current is still slowly rising. I've never seen this before and I've never read about anything like this. Any ideas??? Un-hook battery, go to Auto parts store and buy a new one. :^)

George H.

You're charging it backwards. ;)

Cheers

Phil Hobbs

and it was down to zip voltage. I put a power supply on it and ran up the voltage until the current was at 2 amps. As I watched the battery voltage dropped and the current rose! I double checked all the polarities and it' s wired up right and the ground on the vehicle is disconnected.

rose I dialed the voltage back, lather, rinse, repeat. It is now down to 2 .5 volts and the current is still slowly rising. I've never seen this befo re and I've never read about anything like this. Any ideas???

Certainly sounds that way. And I'd be real careful around that battery too. Car batteries don't like being completely discharged and especially don't like being left that way for an extended period of time. Sounds like it;s time for a new battery.

This is typical of a sulfated battery. Depending on how bad it is, it may recover and be usable, or not. Shorted cells frequently happen after this. Otherwise, it will just have reduced capacity.

Jon

There are charging regimes that claim to be able to bust some of the sulphate.

NT

Take a regular battery charger. Put a big filter on it like 10,000 uF. Then in series with one of the leads to the battery insert the secondary of a 6 .3 volt (iron) transformer of sufficient ampacity.

DO THIS OUTSIDE !

If anything, especially the battery gets warm then find a ballast for the c harger, put it BEFORE the filter. You want to maintain that AC.

At this point I would avoid using epsom salts. Someone mentioned shorts ? W ell there is magnesium in epsom salts so...

If the impedance of the battery does not drop epsom salts may fix it. That might last a year. Might. Don't use epsom salts twice, that increases the c hance of big problems.

If you have an ESR meter that resolves down on the milliohms you can get a pretty good picture of the battery's condition. The lower the better just l ike a cap.

But DO IT OUTSIDE. Friend of mine had a car battery explode all over his fa ce and that was not pleasant. Those things CAN explode, although I think th at time was ignited gas, probably hydrogen.

Gas is why you do it outside. I don't remember which is which at the moment but oxygen is emitted when you charge and hydrogen when you discharge, but that could be the other way around.

One of the most dangerous things NOT to teach your kids about is separating water without separating the gases. Gaseous hydrogen and oxygen in the sam e are are extremely dangerous. Proper hydrolysis puts them in separate tank s, not in the air around you. If a battery leaks you can have that, dependi ng. What's more, the mixture in the battery is ripe for a blast.

So do it outside.

en in series with one of the leads to the battery insert the secondary of a 6.3 volt (iron) transformer of sufficient ampacity.

charger, put it BEFORE the filter. You want to maintain that AC.

Well there is magnesium in epsom salts so...

t might last a year. Might. Don't use epsom salts twice, that increases the chance of big problems.

a pretty good picture of the battery's condition. The lower the better just like a cap.

face and that was not pleasant. Those things CAN explode, although I think that time was ignited gas, probably hydrogen.

nt but oxygen is emitted when you charge and hydrogen when you discharge, b ut that could be the other way around.

ng water without separating the gases. Gaseous hydrogen and oxygen in the s ame are are extremely dangerous. Proper hydrolysis puts them in separate ta nks, not in the air around you. If a battery leaks you can have that, depen ding. What's more, the mixture in the battery is ripe for a blast.

Once fully charged they begin to produce H2 & O2 if charging continues at h igh enough voltage. No gas is produced on discharge. If overheated they can also produce sulphuric acid on overcharge. Since H2S O4 boils at 337C I guess it's just carried off as spray with the water, whe re it hangs around as microdroplets in the air. It's fun to breathe - I bar ely waited for it to stop to leap out.

NT

Many decades ago, long before GPS, I worked for a company who, among other things, did marine surveys. Position fixing used triangulation from microwave transponders located on land. These used two lorry batteries, 70AH IIRC, and they needed to be replaced every few days, usually by carrying them long distances. This is part of the reason why I am so short.

I was in charge of workshop battery maintenance, and grew to know and love my charges, and indeed their charges. I tried every electrochemical nostrum going to maintain their vigour.

However, based on my experience, your battery is what us experts would refer to in technical parlance as 'well f***ed'.

Cheers

I did some work for Offshore Navigation Inc, who provided location services for oil rig guys in the Gulf of Mexico, pre-GPS. They used Raydist, a Loran-like HF hyperbolic nav system, and charged a lot for it. They used some Shoran too, which was more like you describe, pulsed microwave transponders.

en in series with one of the leads to the battery insert the secondary of a 6.3 volt (iron) transformer of sufficient ampacity.

charger, put it BEFORE the filter. You want to maintain that AC.

Well there is magnesium in epsom salts so...

t might last a year. Might. Don't use epsom salts twice, that increases the chance of big problems.

a pretty good picture of the battery's condition. The lower the better just like a cap.

face and that was not pleasant. Those things CAN explode, although I think that time was ignited gas, probably hydrogen.

nt but oxygen is emitted when you charge and hydrogen when you discharge, b ut that could be the other way around.

ng water without separating the gases. Gaseous hydrogen and oxygen in the s ame are are extremely dangerous. Proper hydrolysis puts them in separate ta nks, not in the air around you. If a battery leaks you can have that, depen ding. What's more, the mixture in the battery is ripe for a blast.

I'm mostly a battery idiot. I would love my batteries to last longer, but I'm too lazy to take care of all of them properly.. (and no money to pay someone.) Cars, truck, tractor, backhoe, ...and smaller stuff. I've never been able to bring a battery* back to useful life if I measure any thing less than ~11.5 V after a few minutes on the charger.

If you know of any good links, videos.. ? please share.

George H.

What do you think of adding phosphoric acid? I tried that before.

NT

and it was down to zip voltage. I put a power supply on it and ran up the voltage until the current was at 2 amps. As I watched the battery voltage dropped and the current rose! I double checked all the polarities and it' s wired up right and the ground on the vehicle is disconnected.

rose I dialed the voltage back, lather, rinse, repeat. It is now down to 2 .5 volts and the current is still slowly rising. I've never seen this befo re and I've never read about anything like this. Any ideas???

So any wisdom to share? George H.

Thank you, Clive... well said... I needed a good laugh this afternoon.

Thinking about this some more, you may only have one non-shorted cell there. You can let it go for a while to see what happens, but a massively sulfated battery is not likely to come back.

Jon

These were Decca Trisponders - the 'base station' in yellow and the transponders in blue with a directional (90 degrees IIRC) microwave antenna on the remotes and a omni on the boat, not shown...

Fairly short range, I think, all TTL IIRC.

I hooked up the base station to an HP85 computer through a BCD interface and wrote some HP Basic software to calculate and plot a point on a flatbed pen plotter every second. I hooked up a relay to an RS232 output running at some very slow speed to give a contact closure pulse to put a fix mark on the echo sounder or sidescan sonar too. The HP85 could just about keep up, it used a 600kHz 8 bit processor and everything was floating-point by default.

The first time it was used, the skipper couldn't get the hang of running the boat up and down straight lines looking at the plotter, until I made a miniature paper boat and stuck it on the plotter pen, turning it to face the direction away or towards, then the penny dropped.

Cheers

I've never seen a battery come back. That is if you mean by "come back" that it healst itself from bad symptoms like this battery has. And even if it does, so what? Then you still have a battery on it's last legs anyway. Rather have to get one when it leaves you stuck somewhere, at 11PM, in the pouring rain?

Raydist used hf transmitters to go pretty far offshore, way past line of sight.

A raydist system came with an operator who could figure out the hyperbolic coordinates. It was incremental, tracking your location based on the known start point.

I just read this

which is fascinating but grim. A lot of wrecks happened because ship crew had no idea where they were.

This is amazing:

a fleet of Navy destroyers ran hard onto the rocks on an abandoned rocky shore at what is now Vandenberg Air Force Base. Among other mistakes, a suspected 180 degree RDF ambiguity was involved.

On Friday, April 26, 2019 at 12:33:52 PM UTC-4, snipped-for-privacy@gmail.com wrot e:

nd it was down to zip voltage. I put a power supply on it and ran up the v oltage until the current was at 2 amps. As I watched the battery voltage d ropped and the current rose! I double checked all the polarities and it's wired up right and the ground on the vehicle is disconnected.

se I dialed the voltage back, lather, rinse, repeat. It is now down to 2.5 volts and the current is still slowly rising. I've never seen this before and I've never read about anything like this. Any ideas???

Any cells discharged to less than 1.5V are permanently gone, that means 9V terminal voltage to you.

What does ground connected or not have to do with anything. Wait- don't bot her answering.