udiag BST300 Professional Car Battery Tester 12V 100-2000 CCA 30-200 AH Automotive Load Battery Tester Digital Analyzer Bad Cell Test Tool for Red

Very pleased, tested 4 batteries and confirmed my suspicions. Great little tester, many useful features and simple to use. At this price I doubt you could find a better tester of similar features. In vehicle,out of vehicle as well as cranking and charging system tests. Well packaged with great instructions. Multiple tests on same battery produced consistent results.

Works great, as expected! I have had a lot of battery problems in my car because I don't drive too much so it's great being able to check it occasionally versus it just dying unexpectedly like in the past. Works well and definitely a good thing to keep in the car!

Here’s what happened when I went for warranty on it and is more typical than not, I think.1) First they said "The battery isn't charged, go home and charge it". “Can’t test a uncharged battery”They based this on the battery testers overall initial voltage no load reading, which is typical for a failing battery, even when fully charged. How do I prove it is fully charged up to its weakened capacity. Look at the BST300 State Of Charge (SOC) %. That is the % of full charge. Higher the number the more charged the battery is at its weakened capacity up to 100% full charge. With the BST300 next to me and with phone camera screen shots of tester (previous readings earlier that day) I said that’s not what I show. He accepted that and moved on. Besides, I just now took it off a 100 amp charger (cars alternator) so what logic tree branch made the conclusion it was not charged. Watch that over pruning. Maybe their Ouija board needs to be sent back for factory for calibration.Solution: BST300 would show a 95% charge if I needed to backup the undercharge claim, but it was accepted so we move on the testing.2) "Battery tests fine, no warranty". At this point they used a large and expensive looking heavy duty tester set to test the CCA capacity and compares it to the batteries rated CCA that should have been entered earlier which determines PASS or FAIL reading. A small load is placed on the battery and the CCA is extrapolated from that. Their tester was set at 700 CCA capacity battery initially (but I have a 900 CCA battery) which would have given a PASS for my failing battery instead of the FAIL I properly got.Solution: Bring your BST300 with you. BTW, their companies CCA readings and the BST300 were the same. It’s all about the CCA battery setup entered into the tester for the magic PASS FAIL reading. Also, going from say 900CCA (rating) to a current actual say 650 CCA is a larger difference than it seems. Once that number starts slipping, it’s all down hill from there.

This tool must have on a tool box. If you like to do your own maintenance on your car then you need this to check your battery to do a deep test on your Vehicles then you need this.

I'm not real sure what its supposed to show me because if it shows the battery needs "replaced", I put it on a de-sulfating charger for a couple of days and the battery becomes good...so I guess I'm not sure what the "tester" is really supposed to do for me...I would have been better off spending the $37 on another battery minder charger

This tester is easy to use and provides important information. The instructions are adequate. It is a good addition to the tool box.

Works Great !!

Works as advertised. No complaints.