Dual charging mode for car batteries

[duck__dodgers]

A lot of you already know about this, but I didn't know about this until I bought a cigarette lighter voltmeter, battery tester, and dove into the auto electrical rabbit hole.

My car w/LED headlights, doesn't charge the lead-acid battery at 14.4 unless the car's air thermometer reads in the mid-20's; around 14.0v in the low 30's. All when the temps were higher, my car stayed in <13.3v when charging.

This has been standard w/Hondas for a long time, and I guess that my car does it too.

If you're a Normie, this has no impact on you, unless you have a car that is only short-tripped. don't worry about it.

Given what I'm seeing w/my battery and my OCD, I'm going to try to top-off charge it when there are warm spells and see if this does anything to extend the life of the battery from 4.0 years to 4.1 years.

https://search.brave.com/search?q=dual+charging+mode+honda
pdf about the system, https://opensiuc.lib.siu.edu/cgi/viewcontent.cgi?article=1011&context=auto_pres

 

[ctechbob]

Ford generally sets their cars/trucks to only charge the battery to 80%, which would be a good bit under 14v for the AGM's they're putting in them. Some of us up that to 95% plus via Forscan. I'll sacrifice the fuel economy for better charging.

 

[f355spider]

BMW has been using various battery charging algorithms using a BMS (battery management system) for close to 20 years.
What some similar OCD owners do is connect up a charging pigtail either to the battery directly in the trunk, or to the jump starting terminals in the engine compartment and run them out the front grill. They will connect up a battery tender once per week, either overnight or over a weekend. This satisfies the desire to have the battery get a complete charge at least once per week.