Body battery is a useless gimmick

I think my point, apparently poorly stated point, was that "body battery" isn't reliable for such leaps of action.  RHR is pretty actionable, I wear a vivosmart 24/7 that gives me a pretty good approximate of that...but I don't trust the 945's ability to translate that and other HRV measurables into a "body battery."  I agree with the poster it's a gimmick.

Just to reiterate my point about this function's crap design and functionality.

I did HRV test this morning and my body battery immediately jumped from 5 (when it was for 3 days straight) to 71. And there are people who would try to tell me that this is "working as intended".

Yeah right :(

 I had it a couple of times at 5% for 2-3 days , both cases I was starting to get ill. One night drinking a bit more and I can see the diference in charging. Not well rested or a bad night sleep the same. So, it is working just fine for me. 

So you always have the option not to use it. As you can see it is working fine for many.

IMO body battery is working and it reflects exactly my real body situation; i.e.: I already know what to expect if I go to sleep after a dinner with friends (and wine...) my body battery recharge of only a few points and that's correct because most of the time the sleep is not really a resting sleep...so, my Garmin understands what's going on, from my HB and from my movements during the night and this reflects in the amount of charge I'm getting from the night...

Also have to disagree. It may well be a gimmick but it is not useless. The value does track my feeling of energy levels when I do look at it, but I don't use it to drive any behaviour. It's a nice simple single figure metric for how rested I feel.

Like most of the comments in this thread - I can't agree with you. It's very nice feature and in my case it works perfect. I see correlations between my state and Body Battery value. Also it gives me possibility to see impact of events in my day... for example: sleep quality, fatigue after training, body weakness or illness, hangover. IMHO Body Battery and Resting Heart Rate are very useful - not only for active person, but for majority.

My biggest issue with Body Battery is I don't understand how it calculates the time when I am sleeping and not wearing my 945.  I use a Vivosmart as my normal fitness tracker and it will track sleep/stress/etc but it does not have a body battery feature.  Yet, when I go to sleep each night my 945 says my Body Battery is one number and then when I wake up the next morning it's a different number.

BUT it never maxes out at 100% each night despite my vivo telling me my stress level (from HRV) was exceedingly low.  So I don't know where the 945 getting its rating from.

5% is the lowest the Body Battery will go (so people don't think they died? :D). It is normal for me to hit 5% and stay there on very extended workouts (12h+ rides and runs). It does recover from this state for me though. It seems to me, something is very wrong with the heartrate data the watch is getting - maybe try the fitting guides (where to wear the watch and how snug to fit it), maybe shave some hair off if you have hairy wrists :).

You should be ranting about the HR sensor being off, not blaming it on body battery.

Also check the HR sensor for cracks or even dirt. I know that some Garmin watches were prone to cracks developing in the plastic of the HR sensor, which are bound to impair the function at some point.