RX450h left for a month.

flookyk · April 14, 2023

It is now three and half weeks since I left my car at a hotel near an airport in order to come back to the Philippines, and around another week to go before coming back.

Following advice on here I bought a solar charger panel to make sure the 12V Battery was OK and also bought a Stoplock steering lock for extra peace of mind.

As long as the Lexus Link app is working correctly then it's so far so good with it telling me the Battery is still showing green for good and still in the same place I left it.

The advice on here was, and always has been, most useful.

welland · April 16, 2023

Which solar panel did you buy?

flookyk · April 17, 2023

10 hours ago, welland said:

Which solar panel did you buy?

Just the Halfords 10W

flookyk · April 23, 2023

Well ... got back yesterday morning, dropped off at my car by Emirates chauffeur, unlocked car then opened rear no problem then unplugged the solar charger and started with everything working.

The advice was spot on ... the solar did its job, I would have been worried without it fitted leaving it for the month.

Sybaris · April 23, 2023

I have a 4.8 watt charger, never used it yet but wondering if that will do?

Herbie · April 23, 2023

46 minutes ago, Sybaris said:

I have a 4.8 watt charger, never used it yet but wondering if that will do?

I don't think I've needed to do this since my apprenticeship but, if I'm right, I (current) = P (Watts) / V (Voltage)

P (4.8W) divided by V (12V) = 400mA

If everything is alright with the car we can say that the quiescent current draw is nominally 50mA. So in theory, you're pushing more into the Battery than is coming out, so yes, it should do.

Given that I completed my apprenticeship in 1978 and only worked as an electrician for two years after that (rest of my career was as a telephone engineer with BT) I've probably got something wildly wrong but there you go.

ColinBarber · April 23, 2023

The problem with solar chargers is the power stated is the maximum they produce - on the brightest day, fully aligned. Realistically at this time of year you are going to get 1 W average over 10 hours from the 4.8 W charger and then nothing for the rest. So that's 10 Wh per day. At 50 mA (and I think that's a little low if you have keyless entry enabled) the vehicle will consume 0.05x12.8x24 = 15.4 Wh per day. So the solar charger will help slow the rate of discharge so the vehicle can be left for longer but it isn't going to stop the Battery going flat over a prolonged period.