VAT 40 Battery tester schematic

So I have reverse engineered the VAT40 Printed Circuit board and I can't seem to figure out a general theory of operation for this. I'm hoping there are some electrical enthusiastics here that can help me with this.

Here is the link to the schematic: www.schematics.com/project/vat-40-40755/

I know the basic theory on op amps and transistors....however, I can't seem to make heads or tails out of this schematic. Any help would be much appreciated. Thanks, Eric.

The picture didn't load. Not that I would be of much help, but I was curious to see the diagram.

It is too big of a schematic to load on a phone. Try loading on a laptop or computer.if that still doesn't work let me know and I will upload a pdf. Thanks.

You will probably find it easier to follow some of the projects for DIY DC clamp meters that are on the web than follow Suns's version. Having said that DC clamp meters are now so cheap to buy that I don't think it makes any sense to go the DIY route as it would be probably be a lot cheaper to buy something like a a UNi-T UT203 than home brew your own. I use a a Uni-T UT203 with my Carbon Pile load tester for batteries or my 100 amp battery tester when testing alternators.

These days on recent car models even on very small cars you find pretty big batteries Ford are using 65ah batteries on 1100cc EcoBoost cars. As it is normal to load test a battery at 3x the Amp Hour rating for that size of battery you need to draw roughly 200 amps to test the battery for a dead shorted cell. That kind of current and higher you can only really draw with a carbon pile tester. For some reason Carbon Pile testers are more than twice the price in Europe they are in the USA.
The modern way to test batteries is to use an AC impedance tester which are now available at very reasonable prices. Autel even make a handheld scantool with one built in. But I find in practice I have to do both the old style and hi-tech tests.

Hi. Old thread, I know, but I can't get the schematics.com site to validate my registration. Is there another way I can get this schematic? I'm reconditioning a VAT-40 and plan to do a couple of youtube vids for this operation. Thanks.