jiffy

I have an 04 that's pretty much only driven on weekends. The battery dies out after 4-5 days. Whether there's a drain or not this seems to be about expected and a solar panel battery charger that you mount to the glass seems to be my best option to keep the battery topped up. If gives you an option to connect it directly to the battery but I'm not clear on how that works getting that wire from the inside of your car to under your hood. The easiest connection looks to just be the lighter but it needs to be "live" in order for that hook up to work. Can anyone confirm and if not, does anyone have any direct experience with one of these?

rkw77080

Confirmed. All three lighter receptacles are "switched" with ignition via relays. Refer to the diagram below, you can pick another "always hot" fuse to connect your charger.

Striker223

Check for a drain? Then if there is one solve it?

jiffy

Thanks for the diagram but I hardly know what I'm looking at and how I'd apply that knowledge to a step by step tutorial. I know absolutely as little as humanly possible with respect to my car and I apologize to the faithful lexus and car lovers of the forum for that. Has anyone used a variant of one of these for your own cars here and how did you go about connecting it for regular use? Again I want to make this a long term/permanent addition as I almost never need to drive

Debonair

I would run a 12v (+) and a ground (-) wire from the battery into the cabin. This would be the same process as wiring for an aftermarket amplifier except you stop in the cabin, not the trunk. Then install a cigarette plug or use the plug they supply routed into the glove box or wherever. You could even swap one of the existing cigarette outlets to be direct to battery. Make sure you fuse the positive cable at the battery though.

There are lots of videos and guides on getting the wires from the engine bay into the cabin for amplifier purposes. Any stereo shop can do this for you too.

Has the battery been tested?

Tom57

Before buying a trickle charger, check the alternator output and the health of the battery. Even with the SmartAccess system "on" (keyless entry), the battery should not be drained in 7 days. Your mileage and whether the car is mostly in hot weather determines the life of the alternator. You can check alternator output at the battery using a multi-meter, or use the onboard diagnostics on your multi-screen. Over 14 volts is excellent. But as the charging volts drop below 14, charging of your battery on the short weekend drives is insufficient to recharge the battery.

I've replaced alternators on my LSs with remanufactured OE and it makes a huge difference in fast starts, longevity of battery between starts, as well as the cold-cranking amps to start up the engine here in the dead of cold winter.