Lead Acid Car Battery

On Friday, April 26, 2019 at 12:33:52 PM UTC-4, gnuarm.de...@gmail.com wrote:

I'm charging the battery on a vehicle that has been sitting for a while 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.

The charging started at about 10 volts on the battery. As the current 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 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 bother answering.

--

Rick C.

- Get a 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[Mike Perkins]

On 26/04/2019 19:40, Jon Elson wrote:

On Fri, 26 Apr 2019 09:33:48 -0700, gnuarm.deletethisbit wrote:

I'm charging the battery on a vehicle that has been sitting for a while
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!

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.

Sulfated batteries tend to rise in voltage, not fall to nothing.

The OP is either charging with reverse parity, or has a number of
shorted cells. I have come across one or 2 shorted cell but no more.

If active material is moving between plated, sometimes a hefty thump can
remove a short.



--
Mike Perkins
Video Solutions Ltd
www.videosolutions.ltd.uk

 

On Saturday, April 27, 2019 at 3:05:42 PM UTC-4, John Larkin wrote:

On Sat, 27 Apr 2019 11:48:19 -0700 (PDT),
bloggs.fredbloggs.fred@gmail.com wrote:

On Friday, April 26, 2019 at 12:33:52 PM UTC-4, gnuarm.de...@gmail.com wrote:
I'm charging the battery on a vehicle that has been sitting for a while 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.

The charging started at about 10 volts on the battery. As the current 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 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.

I've had car batteries discharged to 0 volts. Standard cheap chargers
won't even try to charge them, so they have to be bootstrapped with a
real power supply before the charger will take over.

They recovered fine, but they were discharged for less than a day.
Maybe longer term zero volts would be fatal.

Right , there's a time element involved, and a lot less of a discharge to 0V will do it. You'll find the better automotive inverters have a low battery cutout, and it should be programmed for 1.75V/cell.

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[Clive Arthur]

On 27/04/2019 00:37, George Herold wrote:

On Friday, April 26, 2019 at 6:55:36 PM UTC-4, Clive Arthur wrote:

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.

So any wisdom to share?
George H.

Don't buy cheap reconditioned lorry batteries unless you have access to
fit young men to carry them from the nearest road to the cliff-top trig
point and replace them every couple of days.

Otherwise, nothing much helps if you're going to flatten them, and you
will flatten them because no-one's going to swap the batteries after a
long days work when the pubs are open.

Oh yes - don't check for hydrogen with a match having forgotten about
the oxygen. Sulphuric acid vapour irritates and loud noises cause
temporary deafness along with visits from management. (Luckily this was
just a small battery.)

Cheers
--
Clive

 

I've learned something from this exercise. Costco batteries are not the value they used to be. They used to have a good price and a great warranty. Now the price is as high as anyone else, maybe higher, and the warranty is no better or maybe worse. A battery for my pickup was over $90 even after subtracting the core charge and only a 42 month warranty!

Next time I'll shop it around. I'm sure I can do better.

--

Rick C.

+ Get a 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209

 

On Wednesday, May 1, 2019 at 8:07:51 PM UTC-4, gnuarm.de...@gmail.com wrote:

I've learned something from this exercise. Costco batteries are not the value they used to be. They used to have a good price and a great warranty.. Now the price is as high as anyone else, maybe higher, and the warranty is no better or maybe worse. A battery for my pickup was over $90 even after subtracting the core charge and only a 42 month warranty!

Next time I'll shop it around. I'm sure I can do better.

--

I think for lead acid batteries, you can judge the value by comparing dollars/pound.

m

 

Idk where you are, but $90 for a battery for a pickup sounds very reasonable. That's not much more than a fill up with gas and unlike that you only have to do it at long intervals.

 

On Thu, 2 May 2019 16:20:44 -0700 (PDT), trader4@optonline.net wrote:

>Idk where you are, but $90 for a battery for a pickup sounds very reasonable. That's not much more than a fill up with gas and unlike that you only have to do it at long intervals.

Wow! Gas is expensive where you live!

 

On Thursday, May 2, 2019 at 7:20:49 PM UTC-4, tra...@optonline.net wrote:
> Idk where you are, but $90 for a battery for a pickup sounds very reasonable. That's not much more than a fill up with gas and unlike that you only have to do it at long intervals.

The last battery I bought at Costco was more like $60, but I may be mistaken. Costco had a peak of value where it was around $50-$60 for a battery with a 9 year warranty... yes, 9 years prorated after the first 3. I actually replaced one in the fourth year and only paid $15 or something like that. The last two I've bought there have gotten more expensive and shorter warranties.

--

Rick C.

-- Get a 1,000 miles of free Supercharging
-- Tesla referral code - https://ts.la/richard11209