Testing Car Battery with Digital Multimeter?

[Mickyfin]

Ok, simple question as Im having a blonde moment. I have my old car battery indoors, and my charger states that its full, but I have my reservations, and wish to check it with my multimeter.

As you can see from my photo below of said multimeter, I have no 50 Volt setting, so could someone please tell me which setting I need to set it at, and which leads plug in where?



Thanks

[1664]

Why do you need a 50v setting? The selector is at 20vdc in the picture and that's fine for measuring a 12V battery.

The black lead is in the right socket ie, the 'common' or COM. The red lead needs to be plugged in the socket on the right V Ω HZ

[Oldiebut goodie]

It would be better to use a hydrometer to check the SG of the battery electrolyte (providing that you don't have one of these stupid new EC requirement batteries that cannot be filled or checked).
Using the multimeter you need to leave the battery for at least 24hrs. after charging to check the charge.

[jamesc76]

https://club8090.co.uk/forum/viewtopic.php?f=39&t=97077

This will give you a good idea!

[Mickyfin]

Cheers guys, much appreciated

Battery reading 12.98, so seems to be ok.

Thanks again!

[jamesc76]

Cheers guys, much appreciated

Battery reading 12.98, so seems to be ok.

Thanks again!

Remember tho that is with no load on it at all! try measuring the voltage whilst you crank the engine that will tell you a lot more about the battery!

[Mickyfin]

Good point. Will do just that soon

[pauly8888]

(providing that you don't have one of these stupid new EC requirement batteries that cannot be filled or checked)

What's the deal with these stupid batteries? My old battery was constantly going flat, so I bought a new one. I couldn't check the acid in the old battery because I couldn't get the top off. Seeing as though I was going to chuck it anyway, I managed to get the top off with a screwdriver and much swearing (ruining the top in the process). There was NOTHING inside. Dry as a bone.

[Mickyfin]

This new one I have, although a powerful 80ah, its also sealed with two breathe holes. Its classes as maintenance free.

[kevtherev]

no such thing as maintenance free..
batteries use water ... period

it's maintenance free for it's warrantied period probably

[California Dreamin]

The newer battery types based on Calcium and Silver technologies produce less gas and don't use as much water as your traditional lead acid battery but as Kev says there really isn't such thing as maintenance free although they are classed as such because you can't top them up.
The reasoning is simply, they will last long enough to fulfill their stated warranty period.
In addition to the basic voltage check (yours is very good by the way) you need a basic cold cranking test (where the engine is prevented from starting and cold cranked for 10 - 15 seconds) the volt meter should hold steady not dropping much below 10.5 volts (remember the battery needs to be at least 70% charged to do this test)


Martin

[Oldiebut goodie]

(providing that you don't have one of these stupid new EC requirement batteries that cannot be filled or checked)

What's the deal with these stupid batteries? My old battery was constantly going flat, so I bought a new one. I couldn't check the acid in the old battery because I couldn't get the top off. Seeing as though I was going to chuck it anyway, I managed to get the top off with a screwdriver and much swearing (ruining the top in the process). There was NOTHING inside. Dry as a bone.

I had one exactly the same - the little green lying eye said it was good but it wasn't holding a charge, hacked the welded on top off..... no water in most of the cells. Built in obsolescence and guaranteed income for the battery makers.

[Mickyfin]

The newer battery types based on Calcium and Silver technologies produce less gas and don't use as much water as your traditional lead acid battery but as Kev says there really isn't such thing as maintenance free although they are classed as such because you can't top them up.
The reasoning is simply, they will last long enough to fulfill their stated warranty period.
In addition to the basic voltage check (yours is very good by the way) you need a basic cold cranking test (where the engine is prevented from starting and cold cranked for 10 - 15 seconds) the volt meter should hold steady not dropping much below 10.5 volts (remember the battery needs to be at least 70% charged to do this test)


Martin

Cheers for that Martin, I will be giving that a go to see how it fairs.