12V battery at 12.5 volts. Should I worry about sulfation?

I’d read up about their accuracy first. For measurements in the range of say 10-100 milliamperes I’d stick with a simple digital multimeter: it may be more difficult to connect, but the readings are more accurate I think. It’s not that hard either, you just need to think it through.

note in the attachment: manufacturer specs accurac of 0.1 amp at low extreme. There’s a 1000 milliamperes in an amp, so that’s 100 milliamperes. And that’s its limit of accuracy. Somewhat analogous to using a 1/2” torque wrench to install spark plugs.

 

No… You are looking at the 600-A and 1000-A models. Of course you wouldn’t get a fine resolution with such a high current range.

The 100-A model has a resolution of 1 mA. That is the one you should get if you want to look at the battery current.

In any case, you cannot determine the parasitic drain in a modern car using an ammeter. That is because the parasitic drain is a charge (time integral of current), not a current. The current will vary throughout the 24-hour period as various electronics kick in and out. An instantaneous current measurement will not help you. Therefore, you need to get a cheap Bluetooth battery monitor instead, and deduce the battery charge from the battery resting voltage (I posted the charge-vs.-voltage table earlier), which will give you an accurate estimate of the parasitic drain and also tell you how the car is charging and not charging the battery.

 

Yes, what you are really interested in is the SOC drop because that shows how much charge is being lost. For that, you can use the table I posted to correlate the resting voltage with the SOC. Now, the table varies from battery to battery, but it should be a good estimate.

Yes, you can estimate the average current by using the battery capacity in Ah. It is true that the capacity will vary with the discharge current (C/20 for the standard rating as you said, which is 2.25 A for 45 Ah), but it should be a good estimate for smaller currents, too.

 

Anyone know how I can make a post? Not seeing an option have and issue with my 08 driver headlamp