UKC

I’m after recommendations for a handheld GPS that is suitable for a solo Bob Graham attempt? Any recommendations?

So c24hr battery life or replacable batteries then.

I used a Garmin Etrex 20x for a solo Paddy Buckley attempt. Don't think I replaced the batteries but then I didn't finish! It's easy to replace them anyway.

These, are fairly small, relatively cheap and easy to use but they are old technology now so it might be that there's something better out there now although I think the battery thing might be the limiting factor.

I guess replacing the batteries mid way would mean breaking the exercise into two sections? That might not be an issue for you. 

If it is and you don't have a device with 24hr battery I think most devices can be charged on the go from a small power bank. 

My garmin instinct watch charges from 10% to full in about 30 mins and takes vert little out of a small power bank.

As the OP asked for a handheld GPS I assumed it would be for navigation rather than recording the activity.

Would you consider a Fenix 6X? Routes are quite easy to follow and the 24 h would be no problems, but you would need to be quite organised with your GPX upload. You could also plan your schedule and using PacePro you can get a feel for whether the slope should be altering your pace. I used this recently and it helped me keep my pace down when I was being enthusiastic and made me feel better on the slow bits. Of course, this is only really applicable if you need/want a running watch! I would love to be fit enough to have a go at the Bob Graham – good luck.

I have an old 60CS, but it will only do 7-8 hours on 2 AA batteries, so you would need three sets for that.

Id highly recommend a Garmin Etrex 20, there might be some 2nd hand ones available, thats how I got mine and its the best purchase Ive ever made for the outdoors. I use it for cycling, running, hiking. I get about 36h out of good rechargeable batteries and would happily pay full price for one if I needed to replace it.

I am assuming you could do the same with a hand held and thinking it would also charge pretty quickly from a power bank.

Depends on the device I guess, wouldn't work with the one I use but might with others. I've never used a power bank on the hoof, sounds like it might be fiddly?

I know of someone who has Fenix 6X Pro Solar that has crazy battery life being advertised. He managed to kill it in 23 hours and it run out of the juice before he finished BGR in just over 24hrs. Having auto backlight at night, using it for nav and keeping the screen on will kill it. It’s frustrating Garmin’s figures are nowhere near real life numbers. 
 

I have a Fenix 6 Pro Sapphire that should last 30hrs and it doesn’t get that with default settings. If you turn screen off (the actual display - not just the light; it comes back on with a button press or wrist flick) it will last longer. On my Ramsay Round, I had screen off by default (turned back on at final descent) and nav on all the time. Finished in sub 20hrs, had 30-something % battery left. 
 

I am doubtful my next watch will be Garmin 😡

I have good experience, but only since I turned pulse oximetry off. Not done a 24h race, but 6.5 an still >80% all bells and whistles. 

I would recommend it too. Had mine for several years and used to use it in conjunction with my Garmin cycle computer which had a nasty habit of crashing after 60 miles and losing all the data.

Beware the older Etrex 10. Some, including mine, had a nasty habit of switching off for no reason at random times. You had to keep checking the dam thing every few minutes to make sure it was still on.

Garmin Etrex 20 or 30. Pretty small and light, and will easily do more than 24 hours on two AAs