On my 2011 NA spec LR4 HSE with 60k miles I had a series of 3-4 dead battery issues over the last 6 months on a 2 year old Interstate H8 100AH. Also a series of "low battery" warnings to start it. But, a lot of around town short trips, which always preceded the failures. A volt meter at the terminals consistently found 12.2-12.3v after these short hops. The LR4 is still under a CPO warranty, and when checked the dealer techs repeatedly said the battery was fine, charging system working, etc., all good.
Well, I finally had it when stuck in the Sierras with a dead battery last week so put in a fresh Deka H8 AGM, reset the profile using the IID BT tool to H8 100ah HD, and reset the battery monitor. All good. But the next day, running the IID tool's graphing live values for the alternator voltage, charge, and battery capacity, I'm a bit confused.
The morning after the install the battery was at 12.60v before first start up (the evening before it was 12.67v after install). Once the car was started, over the first 15-20 minutes idling/starting/idling cycle, the car sucked the battery down to 12.3v then 12.2v. The only charging took place during the first 30 seconds or so after startup at 14.7v, then nothing. The IID graphed the battery at a constant 83-85% state of charge, all while running the car depleted it from 12.4 to 12.2v.
So after 20 minutes of mostly idle, with a few restarts, with no charging being shown including if revved, I took it for a drive around some hilly areas, 15-45mph. On flat stretches, the alternator wasn't kicking in... voltage stayed at 12.2v. Going down hills, if you touched the brakes, immediately 14.7v kicked in until off the brakes. Then back to 12.2v. cruising around under 45mph. I didn't try it on the highway, but wow, unless it's a "start-up" emission battery algorithm, this is pretty severe profile even if it gains a mpg or two.
At 12.2v state of charge the car should be throwing everything its got at bringing the battery up rapidly to a safe state of charge. Anybody else look at this issue? Is the system just this emission sensitive during the first 20 minutes of start-up routine and working properly? Or is something wrong?
I have the traxide kit and a second battery on the shelf but if on short hops, the profile doesn't do well with keeping the primary charged, it likely won't appreciate a second one to maintain.
Thanks
Well, I finally had it when stuck in the Sierras with a dead battery last week so put in a fresh Deka H8 AGM, reset the profile using the IID BT tool to H8 100ah HD, and reset the battery monitor. All good. But the next day, running the IID tool's graphing live values for the alternator voltage, charge, and battery capacity, I'm a bit confused.
The morning after the install the battery was at 12.60v before first start up (the evening before it was 12.67v after install). Once the car was started, over the first 15-20 minutes idling/starting/idling cycle, the car sucked the battery down to 12.3v then 12.2v. The only charging took place during the first 30 seconds or so after startup at 14.7v, then nothing. The IID graphed the battery at a constant 83-85% state of charge, all while running the car depleted it from 12.4 to 12.2v.
So after 20 minutes of mostly idle, with a few restarts, with no charging being shown including if revved, I took it for a drive around some hilly areas, 15-45mph. On flat stretches, the alternator wasn't kicking in... voltage stayed at 12.2v. Going down hills, if you touched the brakes, immediately 14.7v kicked in until off the brakes. Then back to 12.2v. cruising around under 45mph. I didn't try it on the highway, but wow, unless it's a "start-up" emission battery algorithm, this is pretty severe profile even if it gains a mpg or two.
At 12.2v state of charge the car should be throwing everything its got at bringing the battery up rapidly to a safe state of charge. Anybody else look at this issue? Is the system just this emission sensitive during the first 20 minutes of start-up routine and working properly? Or is something wrong?
I have the traxide kit and a second battery on the shelf but if on short hops, the profile doesn't do well with keeping the primary charged, it likely won't appreciate a second one to maintain.
Thanks