I can’t claim much knowledge about batteries, but I do wonder whether you’re looking for something that doesn’t exist and if it did wouldn’t help you much. This comment ...
Got a new job. Courier work. ... the issue was that when I turn my engine off, remove keys from ignition and lock my car so many times a day towards the end of the day the battery struggles to start the car.
...
Lithium resolved this problem. I can turn engine off and on all day long and it won’t struggle to start.
... suggests that your usage cycle is such that the car doesn’t run long enough to keep the battery charged given the number of stops & restarts you do. Surely any battery will eventually run down under those conditions? A fancy battery may take longer than a conventional one, but eventually you’ll have to charge it whatever type it is. The fact that stop/start isn’t working is just an early reminder that the battery is struggling. Fudging the stop/start with some clever electronics, even if that can be done, won’t prevent the need for recharging the battery at some point, either with an external charger or by going for a long drive.
I agree my varying usage & changes affect how battery is charging etc, and I am not an expert neither, but I know the basics such as:
- if only doing short journeys / frequent stops, battery will never charge fully and should be hooked up to charger when needed
- a long drive in good weather conditions should get it fully charged
That said most of the time up until recently car was driven mostly on medium and long distance drives, and everytime the battery was replaced for a new one it behaved exactly what I would expect it to, unfortunately getting worse over time and a noticeably poor performance of the battery could be noticed about a year after it’s been installed. I factor in time of the year such as in winter stop start hardly ever works and that’s normal. If battery was replaced in spring, the following spring it was in a poor state and needed to be replaced again before winter. Talking about dedicated stop start battery (supplied and fitted by honda).
Now with this courier work the car still drives a mix of “courier miles” and “normal driving”. I wouldn’t leave it overnight if battery was weak.
A while ago I found an article I can’t find it now about installations of 2 batteries. It was about putting expensive batteries in cars and to ensure their long lifespan an additional cheapest lead acid battery was added to installation and the cheap battery was to be replaced yearly and the good expensive battery last 10+ years. I am wondering if this could be a solution to have power / capacity of lithium and stop-start from AGM (not lead acid in this car for stop start) but I’ve no idea how to potentially install it if there is not enough room for 2 batteries, and how to connect them together?