Which battery maintainer out of two?

Sorry, I could not find an appropriate forum for this question, so asking you 4th gen gurus with experience
I have two chargers/maintainers.
The first one after it charged the battery to 100% it keeps constantly fluctuating from 13.4V to 13.55V non stop never dropping below 13.4V.
The second one after charging the battery to 100% it drops to 12.7V and stays there forever.

I have my 4runner which starting from the next week i'm going to use approximately ones a week for 5-10 mile runs during summer months and stay in the garage during winter 100% of time.

Which one do you think is a good charger and behaves correctly for winter/long time maintainer?

 

My choice would be something smart like a Ctek that can condition the battery as well as maintain charge.

 

These work to charge or maintain any type of battery. I throw something like this on my 4runner while I am draining the battery testing stuff while the car isn't running.


Thats really interesting though because 12.6 ot 12.7 is the battery voltage when topped off.

sounds like the ither one id always trying to charge maybe?

sounds like both would work?

$50 NOCO GENIUS2, 2A Smart Car Battery Charger, 6V and 12V Automotive Charger, Battery Maintainer, Trickle Charger, Float Charger and Desulfator for Motorcycle, ATV, Lithium and Deep Cycle Batteries

https://www.amazon.com/dp/B07W6B987...3_nIdjuL_mVQm-lOxr720xLbdXnZN_toaAhipEALw_wcB

 

Has been tried n true I’ve heard

That’s a good idea
I 2nd noco…have their jump starter n the genius 10 I believe…I don’t keep it on board but hook it up like once a week to keep things freshish

Side note: 27f x2 power agm n also use a voltage booster…
your battery selection may have sway in what you need???

 

Full SOC Battery voltage on a standard flooded battery is 12.6V. I think the one that drops to 12.7V is doing it's job correctly. The other one is charging continuously.