The big voltage rip off in my SUV
Since day one, I've always had marginal charging ability from my VW Touareg to charge up the travel trailer battery on trips. Almost without fail, driving and trailering all day, the silly 1/3 or 2/3 charged wall light indicator would show 2/3 charged within minutes after stopping for a lunch break or a Wal Mart overnighter.
Yesterday, I was dinking around with the electronic control module with some Ross-Tech Volkswagen Audi Group (VAG) software, and that software allowed me to see and set all kinds of parameters. The clue to me was that even after starting up glow plugs on a cold motor, the maximum Voltage ever shown on my Scan Gauge II was 14.2V. It would drop down to 14.0 or 13.9 within minutes. And it was then, when I saw the adjustment in the Ross-Tech for voltage charging setup, that I saw that my SUV diesel is set for running a factory AGM battery... and a factory AGM battery should get, tops 14.4V, and 14.4V is not enough for my T-1275 to keep it topped off and fully charged while driving.
So forgive me for having a double facepalm moment. The point is don't mix types of batteries and expect 100% performance. Eventually, I may get an AGM battery that likes 14.4V for my travel trailer. Or just set up the solar panel quickly when I get to a campsite and hope I have a few hours of daylight left to get that last 25 or 30 AH back into the battery and topped off before night fall.
But a fussy charging 14.8 or 15.0V demanding battery on the trailer and an AGM that likes 14.2 to 14.0V from the alternator on the SUV is not the best working combo while driving down the road trying to get to my destination.
Yesterday, I was dinking around with the electronic control module with some Ross-Tech Volkswagen Audi Group (VAG) software, and that software allowed me to see and set all kinds of parameters. The clue to me was that even after starting up glow plugs on a cold motor, the maximum Voltage ever shown on my Scan Gauge II was 14.2V. It would drop down to 14.0 or 13.9 within minutes. And it was then, when I saw the adjustment in the Ross-Tech for voltage charging setup, that I saw that my SUV diesel is set for running a factory AGM battery... and a factory AGM battery should get, tops 14.4V, and 14.4V is not enough for my T-1275 to keep it topped off and fully charged while driving.
So forgive me for having a double facepalm moment. The point is don't mix types of batteries and expect 100% performance. Eventually, I may get an AGM battery that likes 14.4V for my travel trailer. Or just set up the solar panel quickly when I get to a campsite and hope I have a few hours of daylight left to get that last 25 or 30 AH back into the battery and topped off before night fall.
But a fussy charging 14.8 or 15.0V demanding battery on the trailer and an AGM that likes 14.2 to 14.0V from the alternator on the SUV is not the best working combo while driving down the road trying to get to my destination.
