Our 2.5 - a battery biography

[White Exec]

Idly raking though log of battery replacement on our '96 2.5, since getting the car 'new' in 1999.
.

2.5's batteries.pdf

Click table to enlarge

A spell of neglect after we moved to Spain in 2004, and the car was laid up.
Thereafter, fitted Yuasa 096's (currently Yuasa YBX3096), which have not disappointed.

** An investment in a CTEK MXS3.8 intelligent charger in 2015, and with the car getting regular use now around once a week for long and very long journeys, I just leave it hooked up to the CTEK in the garage, where it always starts on-the-button.

Looks like battery life is now around 5 years; will be interesting to see if the CTEK does anything to extend that.

[sageman]

Would be interesting to know the voltage drop/self discharge between uses without your charger which I would think holds your batteries at 13.6v on float

It’s worth noting excessive float charge on a typical car battery will cause positive grid corrosion if the battery isn’t excisized
As you’re using yours every week or so this is unlikely to have any major affect and it’s less noticeable on an engine start battery compared to a domestic/house battery bank in a boat or RV

Battery’s that are being left for very long periods are better left disconnected and put on a charger (preferably a smart charger) every month or so

[White Exec]

With the unit at Step 6, the charge settles to 13.47v, pulsing at 2Hz, with average current showing on a meter as 7mA.

https://www.ctek.com/storage/ma/0f89342 ... -UK-EN.pdf