I don't think I'd rely on that test if I was going way out in the field somewhere. You can usually get a tester at Harbor Freight for free or close to it with just about any kind of purchase. Regardless of which way you test a battery, it's best to just carry some spares with you. Batteries that test good can still fail.
I keep a 16 pack in the Jeep, and a change of batteries in my finds pouch, nothing worse than dead batteries in the middle of an awesome spot!! a mile from the Jeep.
That's the first I've ever heard or seen that one. I will have to try that out for sure because I just don't believe it. It would have held a lot more weight if the batteries were both the same brand in the test. I would say its a difference in the manufacturing construction between the brands. I could be dead wrong but surely this would be a known way of testing batteries way before now.
You cannot correctly test a battery with a testing machine, in the manner shown. Just testing a battery for voltage does not show the condition of the battery under load. Even a battery that is nearly dead will still show a high voltage, but put that battery under load (like using it in your md) and the voltage will go way down. To correctly test a battery you must place a load (resistance) on it while checking the voltage. And, if you have a good electrical tester, you can do just that.
Interesting video but this is just another example of "black and white thinking". Most batteries are usually somewhere in-between "totally dead" and "totally good". This bounce test likely can't show you the minute differences between different batteries in the questionable range. Still, it is an interesting test and I'll have to give it a try to see if it really holds any water.
Ok I have been bouncing batteries for days now. Can we get a Mod to take down this video? I would not trust it. But it is interesting haha. I always take a lot of extra batteries. Even though my detector says they are good I feel the machine does better with fresh sometimes. Maybe it gives me more confidence?