• Welcome, Guest! We hope you enjoy the excellent technical knowledge, event information and discussions that the BMW MOA forum provides. Some forum content will be hidden from you if you remain logged out. If you want to view all content, please click the 'Log in' button above and enter your BMW MOA username and password.

    If you are not an MOA member, why not take the time to join the club, so you can enjoy posting on the forum, the BMW Owners News magazine, and all of the discounts and benefits the BMW MOA offers?

VOLTMETER - The Importance Of Having An On-Board Voltmeter

Turning the key to ON puts a load on the battery and a drop of 0.1V is absolutely nothing to worry about.

Depends on your battery type? Do you have a GEL or AGM battery? Or is it just a flooded lead acid battery. 12.6V to 12.65V open circuit (no load) is normal for a flooded lead acid battery.

Flooded lead acid type. So the 12.4 turning the key on, and 12.5 with key off suggests the battery is up to snuff for the trip this summer, IYO?

thanks
 
Flooded lead acid type. So the 12.4 turning the key on, and 12.5 with key off suggests the battery is up to snuff for the trip this summer, IYO?

That is not a real test. I was just explaining why you get a voltage drop when turning the key ON and obviously there must be some kind of load which is normal.

A real battery test is a load test and capacity test. You can do a load test. Head over to Harbor Freight and buy a load tester. I have both the fixed 100A and the variable 500A carbon pile load testers. For a real capacity test, the equipment is too costly and very time consuming. We had a Megger Programma Torkel 860 in the lab...$$$ not meant for home use.

Look if it starts likety-split like when it was new, why worry.
 
That is not a real test. I was just explaining why you get a voltage drop when turning the key ON and obviously there must be some kind of load which is normal.

A real battery test is a load test and capacity test. You can do a load test. Head over to Harbor Freight and buy a load tester. I have both the fixed 100A and the variable 500A carbon pile load testers. For a real capacity test, the equipment is too costly and very time consuming. We had a Megger Programma Torkel 860 in the lab...$$$ not meant for home use.

Look if it starts likety-split like when it was new, why worry.

thanks
 
On my RT, don’t know how to rotate and make the pic smaller
 

Attachments

  • IMG_0616.jpg
    IMG_0616.jpg
    234.2 KB · Views: 210
Picture is fine. They just render properly if the picture was taken in portrait mode (horizontal) if taken with an iPhone.
OM
 
Back
Top