Not unexpected i suppose, it’s 6 years old. Anybody have any idea what apple will do if I take it to them, repair/replacement, cost/what with kinda thing?

Sod Apple! They’ll charge you a hundred quid just to look at it. Take it to any phone repair place and they’ll shove a new battery in it. 5 minutes. 25 quid. Job jobbed.

Anybody have any idea what apple will do if I take it to them

Charge you too much money?

£59 according to https://support.apple.com/en-gb/iphone/repair/battery-power

Or get a battery off eBay and do it yourself:
https://www.ifixit.com/Guide/iPhone+4+Battery+Replacement/3141

Buy a battery and plop it in. Takes 5 mins if working slowly.

I changed the battery on my daughter’s 4s, was indeed a 5 min job. A bit fiddly, and you need good eyesight (or a magnifying glass!), but nothing too complicated. There are loads of videos on Youtube. Cost less than 10€ including the tool you need from eBay.

Thanks fella’s

Check feedback carefully if buying off ebay; don’t just go for the cheapest like I did! The new battery was no different. Lasted a few hours. Phone lives in a dock now as a music device.

(See youtube for changing instructions)

the only way to guarantee a genuine, good quality battery is to get one from apple.

paying more on ebay doesn’t equal better quality.

wysiwyg from here does battery swaps and stuff if you arent confident doing it yourself.

Replacebase

This lot have been good in my experience. You can usually pic a genuine part or what they deem as a decent non OEM part.

Yeah a lot on eBay/Amazon are just old batteries salvaged from phones. Go with a reputable seller with good reviews.

If you use iBackupBot then it can tell you how many recharge cycles your battery has had. That gives some peace of mind.

What actually happens is the old circuits are given new cells therefore software reports say 400 charge cycles as that’s what the circuit stored. In reality the cell is brand new.

As the phone is so old you may decide it’s not worth paying Apple (I’d always recommend Apple for a newer phone). I did my own replacement on a 4S not too difficult (tiny screws and you only need to take the back off which is easy) and the battery / kit cost less than £10 off ebay or amazon. I’d say the battery is ok but not as good as the original but it’s ok.