Sunday morning went to start my 02 Polaris 700 Sportsman...battery was deader than my hope and dreams. So, I hooked it up to my F 150 and started it, the truck was NOT running. After I got the bike started I got a flashing battery icon and the needle was also flashing, but only under a load not when the bike was at idle. Google-fu informs me that it is probably a voltage regulator. My question is did I fry the regulator?

If you have a meter check the voltage at the red terminal with the engine at idle and revved up. The voltage should be higher with the engine revved if the charging system is working correctly.

Should have roughly 13-13.5 volts at idle.

Or it was already bad and that's why the battery was dead when you tried to start it Sunday.

If you let the battery run down from sitting the plates in the battery may have built up sulphur on them preventing the battery to be charged. My truck sat so much without being started the battery went bad like this. A battery tender fixed the problem from happening again.

Those little Battery Tender Jrs are the best thing since sliced bread. I have a couple and all my idle batteries stay nice and fresh.👍

I keep one of these on my Teryx4 LE when not in use......

My Cub Cadet lawn mower also.......

Its only a .75 amp older one.....$30 money well spent

Got one about like it...problem solved,

^^^^THIS^^^^

I think I need a couple of these

I started using a float charger I picked up at Harbor Freight.
I do not use the trickle charger type.
I have a Honda pioneer 500 SxS
I installed a dash board volt meter to show batter charge.
With machine running its around 14 to 14.5.
On the float charger it stays at 13.2.
If I let it sit with out the charger on after a few days the battery reads 11.3
I also carry a booster pack.

Sounds like you have a voltage leak somewhere. You need to spend some time with an ammeter to track it down before it wrecks the battery and leaves you stranded. If a battery gets below about 12.0, it's being damaged.

The one you put a pic of us a charger only, no onboard battery. So, unless you plug it in to an outlet it won’t do anything.

Those jump starters are getting smaller, better, and cheaper all the time. However, I can't find one with enough poop to reliably start my 6.7 Cummins. All of them seem to have a limit of 6.5 and on the few that will go bigger, the reviews say they won't.

They make a noco rated to 10L diesels

That would be the GB150, $300 on Amazon.