bkenobi wrote:I did a basic battery test at home but, as you said, it won't give a real health of the battery. The cables look very clean and secure.
I took the battery to O'Reilly and asked them to test it on the bench. It's from 2015 (don't have date code handy atm) so I thought if bad it might be warranty replacement. The machine only took 2-3 minutes to report that the battery was good, so I'm not convinced they did a load test as that takes around 20 minutes (according to my mechanic). I drove it to a different store another day and had them use the portable tester to check the alternator. That battery test took 30 seconds.
I'm planning on taking it by my regular mechanic or Interstate to get a full test this afternoon. I'll check ground points too now that you located them.
There's three types of load/electrical tests:
A spot test for the battery (auto parts stores can do) - requires bench testing the battery. It's pretty easy to see if a battery fails this and does't take rocket science so 2-3 minutes is plenty.
One for the charging system (some auto parts stores can do) - requires going out to your car and connecting the tester to your battery. You start your car and it goes through a series of tests, takes about 5-10 minutes. Tests alternator charging capability and battery load rating.
One for the entire electrical system - What your mechanic is talking about. - Dealers and many shops (not all) do this one. It's requires connecting the battery and a number of other tracer wires to various components either in the fuse box, or power distribution block of the vehicle.This is the best way to do it but, unnecessary in most cases. It allows them to test specific circuits, read the wave forms on an oscilloscope from circuit to circuit, test for open grounds, intermittent opens, etc.
I forget the technical name of it but it saves shops from come backs and pissed off customers that drive away with a new battery, only to have the same issue(s) shortly after. Learned that one the hard way in my young wrenching days.
This unfortunately is a case where it (entire electrical system check) will likely be necessary. Your battery is good and your alternator appears to be working (indirectly at least).
Most shops, including dealers, will charge about an hour of labor to run the test. IMO it's worth the time savings of trying to trace out the wires/circuits yourself.