iPads don't charge unless turned off.

You need to be using either an Apple 12W power/charging adapter block to charge and power these iPads and not a small 5W iPhone power/charging adapter block OR a third party, MFi certified ( Made for iPhone/iPad/iPod ) 12W power/charging adapter block.

Why? The power supply I'm using will provide up to 146 watts - more than 12X the amount of current the Apple charger can supply. I understand that dinky phone chargers don't put out enough current to charge in finite time - but I am providing far better charging than what an Apple charger can do.

Also, if your iPads are not charging properly, your charging cable AND/OR your power/charging adapter may very well be issue and is faulty.

Power/charging cables and adapter blocks fail over time, all the time.

I have tried two different cables. Exactly the same results. One cable going bad is not unreasonable. But two? And a bad cable does not explain the central problem here: Charging only happens at a meaningful rate when the iPads are turned OFF. That is, they draw different amounts of current depending on whether they're on or off. That in itself isn't surprising - one would expect a running machine that is also charging a battery to draw MORE current - but for these two iPads, the situation is the reverse. 90mA when they are turned ON, and 450mA when they are turned OFF.

Also, a 2011 iPad 2nd generation is an over 10-1/2-year old iPad.

It is very possible to internal, rechargeable battery in THAT old iPad is finally, beginning to fail.

All batteries have a finite lifespan.

Agreed. Except it took a full charge a week ago and IS charging now. It's just not charging at 2 amps (10W). It's charging at 480mA (<2.5W). And it ONLY charges at that rate if I turn it OFF. In other words, why would it charge at 90mA when it's turned on, but 450mA when it's off? The battery is the same.

Could be a similar issue with your newer 2017 iPad 5th generation.

The internal battery maybe failing or faulty, in some manner.

Seems unlikely for the same reason that the cables aren't likely to be the problem. Both iPads started doing this within the past month. What are the odds that both batteries would "go bad" in the same month? Oh, and I was able to charge the iPad5 to 100% - it just took 2 days. And I'm charging the iPad2 now and fully expect it to charge to 100% ... in 2 days.

You need to contact Apple support via the contact support link located at the upper right hand corner of every Webpage of these Apple support communities.

Use the Hardware Repair & Battery usage & Charging support categories.

OR

by installing and using the Apple Support app found in the iOS App Store.

Tap the iOS App Store link below.

https://apps.apple.com/us/app/apple-support/id1130498044

Cool! I didn't know there was an Apple Support App!

(** A few minutes later **)

Not so cool.

As is typically the case with Apple, they don't really support anything they aren't trying to get you to buy.

"Apple Support" is not compatible with this iPad.

What jerks.

I appreciate your attempt to help, but I'm afraid this is like trying to get Apple to FIX a piece of hardware. You buy a MacBook. Two years later it dies. Apple's solution is to buy a new motherboard ($1200) or buy a new MacBook. Meanwhile, they're trying to strangle 3d-party repair (where you could get the problem fixed for $150).

I used to champion Apple and hate Microsoft for Microsoft trying to take over and monopolize everything. Now I'm beginning to hate Apple for the same reason. I don't know what happened to helping the customer. Maybe that died with Steve Jobs.

Thanks again.