If you are thinking that the only solution is to replace then you could try a 'factory reset', when my
Garmin 810 starts 'acting up' that is what I do and it often sorts things out; in addition continue to turn off blue tooth and reduce screen brightness. Yes I'd expect battery life to diminish with age but your 4 hours or less is very low, potentially there maybe an underlying issue especially as you say it's never been good; a factory reset may help if that's the case.
In comparison I get about 6 hours on that older
Garmin 810 using the map screen following a course with tbt directions, like you I have turned off blue tooth and reduced brightness. If I need longer I will carry a power bank in my 'bar' or 'top tube' bag, the USB lead reaches perfectly. Last summer I rode an 8 hour day using tbt on the map screen, mid way around the course I was down to 50% battery so I knew I would be pushing my luck just using the 810's battery reserve so I plugged in the Power Bank. When I got home it had charged back up to 100%, the
Powerbank (a Goji G10PBWP17) itself has battery indicator with four LEDs so you know how much charge it has left; it had all four still lit.
I already had that power bank, I didn't buy it with this in mind, it's waterproof and robust but you can get them much smaller, lighter and cheaper. Yes damaging connections could potentially be an issue, the way I look at it this is an old unit and I'm a bit less precious with it than I once was. I have had that power bank three years and only needed to use it once; most of my long days are on routes I know where I don't need the map screen permanently on, I can easily complete those rides without issue. I've seen a few who use a power bank to top up their device at a rest stop which would help minimise potential damage to the Usb connection.
When it does finally give up (
I have had to make a home made 'power button' so fear I am on borrowed time ) I would be happy to update it with another 'Garmin'.
Features wise the
Edge® Explore has all I'd need although the extra battery capacity of the
830 would probably sway me (upto 20 v 12 hours). Yes the 830 is more of an investment but my old 810 has lasted 8 years which is not bad for a piece of tech'; which for me would also be a consideration when justifying how much I am prepared to treat myself. The
530 is cheaper and also has 'upto 20 hours' battery life, I do find the 830 touch screen far more intuitive to use than the 530's buttons, plus the decider for me is that on my 810 as mentioned above it is that one of the buttons that has failed so a unit that has less buttons does appeal.
