Battery voltage dangerously high?

[roadrunnerh]

Hello Guys,
I'm hoping someone could shed some light on this. I tried to start my Scamp just now. Nothing. No crank. Walmart battery has a 07/21 sticker on it. I checked battery 255.3 Volts!?
I removed and replaced with battery from my Road Runner. Scamp started, all good.
Now I have the battery outside the garage and it reads 277.6 V and CLIMBING.
What the heck is going on here? Is this dangerous? Help!

 

[1 Wild R/T]

Call Elon Musk, he'll want to know about this....
Seriously, are you sure you meter is accurate? Test the battery on another vehicle just to verify...

 

[Jerry Hall]

Actually sounds like time for an accurate meter. The battery from your RR, what does it test with that meter. Test it connected and disconnected.

 

[roadrunnerh]

LOL @ 1 Wild R/T

Here's two pics. No change in setting on multimeter.

 

[MIKESPOLARA]

It also has the "minus" sign, batteries toast

 

[roadrunnerh]

An hour ago, It read 255.4 V.
I noticed the tiny "M" next to the "V" on the high reading. But using same setting on MM on RR battery, normal.

 

[roadrunnerh]

Ok, well now I learned something. Whenever I tested a battery that was low, it was below 11 something.

 

[Don Frelier]

The M sounds like millivolts thats equal to the number X .001 so -.28 Volts or essentially nothing.

 

[Jerry Hall]

I was just fixing to ask what that was before the V on the Walmart battery. Don clarified that. Also the minus sign.

 

[roadrunnerh]

Thanks guys for the replies and help!

 

[bm02tj]

The battery has a short in a cell store outside not in your garage

 

[RJRENTON]

Hello Guys,
I'm hoping someone could shed some light on this. I tried to start my Scamp just now. Nothing. No crank. Walmart battery has a 07/21 sticker on it. I checked battery 255.3 Volts!?
I removed and replaced with battery from my Road Runner. Scamp started, all good.
Now I have the battery outside the garage and it reads 277.6 V and CLIMBING.
What the heck is going on here? Is this dangerous? Help!

A 12 volt lead acid storage battery using sulfuric acid electrolyte or an AGM battery will only produce ~ 12.5 - 13.5 volts fully charged open circuit (nothing connected). Your reading of 255.3 volts is not realistic. If your meter is NOT an auto ranging digital device, then you have it set to the wrong scale.
BOB RENTON

 

[toolmanmike]

Walmart battery and a Harbor Freight meter? You should be on VDC scale with 2 digits to the left of the decimal point.

 

[roadrunnerh]

Walmart doesn't make batteries, and it's a Craftsman MM if that even matters...

 

[Jerry Hall]

Walmart doesn't make batteries, and it's a Craftsman MM if that even matters...

Nothing wrong with the meter, it registers correctly. Battery is a core for a new one.

 

[RJRENTON]

Walmart doesn't make batteries, and it's a Craftsman MM if that even matters...

Wal-Mart batteries are made by Johnson Controls.....FYI
BOB RENTON

 

[Photon440]

Some of Wal-Mart's batteries were made by Johnson Controls, but that division has been spun off as Clarios. Wal-Mart also uses Delphi and Exide as suppliers.

 

[kiwigtx]

LOL @ 1 Wild R/T

Here's two pics. No change in setting on multimeter.
View attachment 1157017 View attachment 1157018

That meter is showing 279.3mV (milli-Volts) which means your battery is stuffed, providing of course that the meter is of any decent quality, and the batteries are fresh.

Just over a quarter of one Volt.

 

[bm02tj]

The Auto in the corner is automatic range setting

 

[1 Wild R/T]

Yup... Auto-ranging sucks... Give me a meter that I can select the range.... Yes I know theres a override button to select the range but auto-range is the default...