IPhone 6 Failed battery recharge-

What's the problem? If it's that the battery is completely dead and it won't start, then no. It will need active power in order to transfer contents. If the battery is in bad shape but the iPhone 6 will still work when connected to a power adapter, then that shouldn't be a problem.

sberman wrote:

Not if the device is not working.

That's exactly the reason backups are so important. But backups must be performed before catastrophes.

Not sure a battery failure is that much of a catastrophe as it's not that difficult to replace. However, Apple doesn't guarantee that they won't reset a device brought in for servicing and always leave an out that they'll reset it for technical reasons or perhaps replace the entire device in lieu of a battery replacement.

If you don’t have backups there is a lot more than a failed battery that can cause a catastrophe. For example, the most common cause of water damage to a phone is dropping it in a toilet (really; a study found that 40% of all water damage failures are from this cause). Throwing it under a bus is another. Just dropping it can cause it to fail. Carrying it in a back pocket is a frequent cause of iPhone failures. Lost or stolen. Unless you have nothing on your phone that you care about you should back up frequently, ideally overnight, every night, which is an automatic process after you turn it on once.

Lawrence Finch wrote:

If you don’t have backups there is a lot more than a failed battery that can cause a catastrophe. For example, the most common cause of water damage to a phone is dropping it in a toilet (really; a study found that 40% of all water damage failures are from this cause). Throwing it under a bus is another. Just dropping it can cause it to fail. Carrying it in a back pocket is a frequent cause of iPhone failures. Lost or stolen. Unless you have nothing on your phone that you care about you should back up frequently, ideally overnight, every night, which is an automatic process after you turn it on once.

I was just addressing the situation hoping that the OP doesn't get scared off. If the battery is completely dead, it's something that can be fixed, and fairly easily provided that it's the only thing that's not working. Whether or not the OP wants to access the data without paying the price of a battery replacement is another matter. I understand the hesitancy to sink money for repairs into a device that's going to be replaced, but replacing the battery would be the most economical way to get it in shape to back up the data for transfer to a newer device, where the OP could just do the backup once it's working normally.

It's technically possible to power an iPhone without a working battery to recover data, but I wouldn't consider it worth it compared to just replacing the battery. In my career, our lab personnel typically used external power supplies to plug into battery connections for bench testing.

Lawrence Finch wrote:

There are battery failure modes that will prevent to phone from powering on even when plugged in. Most commonly a shorted battery, which can also kill the lightning cable.

Wasn't thinking of that necessarily. I've seen Apple devices that wouldn't power on but would display a battery icon the display when a Lightning cable was powered and plugged in. Also saw some that just remained all black.

But I was thinking of a direct connection to the battery port without a battery. That done quite a lot in prototype testing and data recovery repair (especially when the battery is damaged).

Not if the device is not working.

That's exactly the reason backups are so important. But backups must be performed before catastrophes.

There are battery failure modes that will prevent to phone from powering on even when plugged in. Most commonly a shorted battery, which can also kill the lightning cable.