Always on 12v for easy battery tender trickle charge lx 570

[highfructose]

Would anyone happen to know where easy access to constant on 12v might be in an lx570?

I mostly drive my vehicle, during the week, 4 miles…then back…daily…which doesn’t charge the battery…which results in weak starts and dead battery after a while. So I trickle charge it once a week or so.

I’d like to add a simple solar battery tender. Looking at the attached

Limited-time deal: Waterproof 12W 12V Solar Battery Charger & Maintainer Pro - Built-in Intelligent MPPT Charge Controller - 12 Volt Solar Panel Trickle Charging Kit for Car Automotive Boat Marine Motorcycle RV Trailer https://a.co/d/7JZy1lk

 

[KLF]

Maybe through the trailer plug in the back, but not sure if it will tolerate back feeding, there might be a diode or relay blocking it. Otherwise you'll have to clip right to the battery.

NOCO sells various harnesses that you could hardwire to the battery then leave a pigtail sticking out behind the grille.

 

[TeCKis300]

Pretty sure the trailer plug won't allow backfeeding. Agreed a pigtail to the battery is the way to go. Could also have the pigtail routed to the base of the windshield for easy access.

I would also suspect that maybe your alternator or battery aren't in great shape. If the battery has already been systemically undercharged for some months, it's likely already sulfated. But root cause would be the alternator. 4 miles is marginal but should be enough to recover? How many miles on your LX?

 

[highfructose]

Pretty sure the trailer plug won't allow backfeeding. Agreed a pigtail to the battery is the way to go. Could also have the pigtail routed to the base of the windshield for easy access.

I would also suspect that maybe your alternator or battery aren't in great shape. If the battery has already been systemically undercharged for some months, it's likely already sulfated. But root cause would be the alternator. 4 miles is marginal but should be enough to recover? How many miles on your LX?

It’s only “killed” the battery to the point that it wouldn’t start once…a couple years ago.

Since then I always plug it in to top it off once a week (same with my other vehicle).

Battery may have been wrecked by repeated short around town trips…bur tbh it may just be in my head that it doesn’t sound like a “strong start” like the 5.7 hemi does.

I think, also, my inner child just wants to add another practical “accessory” to “the fun-vee.”

i have around 100k miles (2011) and the battery is around 3 years old (5 year warranty/expected life)

Hopefully it’s not an alternator, but if it is so it goes. Is there a reliable metric for testing it?

 

[INTP]

I keep my 100 series plugged in to a battery tender with the little harness run through the grill. I only drive it a couple times a month and have not had any problems

 

[highfructose]

This product may offer a means of using an interior solar panels wired directly into an always on “port” for the battery…

I was thinking of maybe trying one in each of the 3rd row windows

VSTM OBD II Vehicle ECU Emergency Power Supply Cable Memory Saver (3Meter) with Alligator Clip-On 12V Car Battery Cigarette Lighter Power Extension Socket https://a.co/d/0HfIwcW

 

[relaxing]

Do people run interior solar panels and it works? You won’t get good solar performance through glass, plus factory tint, plus bad angle relative to the sun… maybe you’ll get enough of a trickle to keep the battery alive?

A panel on the hood or roof would be better.

 

[highfructose]

Do people run interior solar panels and it works? You won’t get good solar performance through glass, plus factory tint, plus bad angle relative to the sun… maybe you’ll get enough of a trickle to keep the battery alive?

A panel on the hood or roof would be better.

I’m not much of a mechanic/engineer, but I was under the impression that the interior 12v plugs we have aren’t “always on…” thus if you plug something into them when the car is off, they’re not “connected” to the battery

Thus in order to use the car’s 12v system to charge the battery with an interior solar panel when the car is off, you would need to find an “always on” 12v source to tap into.

I think the obd2 plug is “always on” 12v thus the plug I posted, if you plugged an inferior solar panel into it, might get the job done.

A hood panel would be nice (though expensive)…and I may go that route…but I figure I would go down the research rabbit hole of the relatively cheap and easy interior solar panel(s) first.

 

[relaxing]

I’m not much of a mechanic/engineer, but I was under the impression that the interior 12v plugs we have aren’t “always on…” thus if you plug something into them when the car is off, they’re not “connected” to the battery

Thus in order to use the car’s 12v system to charge the battery with an interior solar panel when the car is off, you would need to find an “always on” 12v source to tap into.

I think the obd2 plug is “always on” 12v thus the plug I posted, if you plugged an inferior solar panel into it, might get the job done.

A hood panel would be nice (though expensive)…and I may go that route…but I figure I would go down the research rabbit hole of the relatively cheap and easy interior solar panel(s) first.

Oh sure. My concern was with the “panel inside” part, not the OBD2 part.

 

[KLF]

I’m not much of a mechanic/engineer, but I was under the impression that the interior 12v plugs we have aren’t “always on…” thus if you plug something into them when the car is off, they’re not “connected” to the battery

Thus in order to use the car’s 12v system to charge the battery with an interior solar panel when the car is off, you would need to find an “always on” 12v source to tap into.

I think the obd2 plug is “always on” 12v thus the plug I posted, if you plugged an inferior solar panel into it, might get the job done.

A hood panel would be nice (though expensive)…and I may go that route…but I figure I would go down the research rabbit hole of the relatively cheap and easy interior solar panel(s) first.

You are correct that you can't backfeed through the accessory power ports, they are relayed and disabled when the truck is off.

I tried one of those OBD memory savers in a Lexus IS years ago and it didn't work.

 

[bloc]

Not to mention, tapping into any of the OBD wires just isn’t a great idea lest it hamper ability to run diagnostics in the future. If I’m forced to modify any wiring to run an accessory it won’t be any of those.

 

[highfructose]

Not to mention, tapping into any of the OBD wires just isn’t a great idea lest it hamper ability to run diagnostics in the future. If I’m forced to modify any wiring to run an accessory it won’t be any of those.

Yes. Not an ideal solution.

On the upside, yesterday, even on a fully topped off battery, the start still seemed “a little” weak.

Might just be in my head…or maybe the starter for the 5.7 slowly dies and gives you warning so you can proactively replace it.

Time will tell.

 

[daneo]

Have you done a cranking test on your battery? Most parts places will do a couple tests for free to make sure your battery is ok.

If that checks out, I agree with the hypothesis that your starter could be on the way out.

 

[highfructose]

Have you done a cranking test on your battery? Most parts places will do a couple tests for free to make sure your battery is ok.

If that checks out, I agree with the hypothesis that your starter could be on the way out.

That’s a good idea. I actually have a load tester. I’ll give that a go.

 

[highfructose]

Load test confirmed battery was right on the line between weak and bad after full trickle charge…and well into the bad range on second load test.

Local battery place tells me even though their warranty is 5 years, they really only usually last 2-3 years, with the remaining warranty in essence being a prorated discount on your next battery.

Current plan is to attempt to put a group 31 deep cycle (885 cca with 225 reserve vs stock 27f 710 cca and 120 reserve) in there and see how it goes….the 31 deep cycle and starting batteries (1000 cca, 200 reserve) both only have 2 year warranties so I figure the deep makes more sense overall for my application (winch, lights, random electronics).

I’ll likely more regularly plug into the trickle charger so as to counter the harder life my short around town driving seems to give the battery.