Crosstrek batteries

[davidphaney]

I recently had to replace both of the front batteries on my 2016 Crosstrek hybrid at only 35,000 miles (cost: a little over $1000). The dealer acknowledged that this was early for the batteries to go bad, but that a couple of months of inactivity could be the culprit. (car was parked while I was on a long trip with another vehicle). Is it advisable to use a battery tender on these batteries during long periods of inactivity in order to lengthen battery life? One is a standard starting battery the other is the hybrid system stop-start battery, which costs over $600.

 

[olliesgrandad]

A battery conditioner for the standard battery would help, but I don't understand why the hybrid battery would give issue. I've just come from 4 different Lexus Hybrid models and their hybrid batteries are so bulletproof they warrantyy them in UK for 15 years if you have an annual check up.
I have a Ctex battery charger /conditioner that I use if our cars are laid up.