Leaving car at the Airport Holiday

[scoobeesnac]

I'm not convinced 4.8W is anywhere near enough. I have a 20W solar PV I leave in the window facing south when I leave it for extended periods (like 3 months at a time) and that only just keeps the battery at 12 V. No camera on that. When I have the camera in, I use 2 x 20W panels.

According to the battery monitor there is only a trickle loss over time so I don't expect it needs much on our vehicle - I did look at the 20w+ solar panels but the efficiency seems to vary and the reviews on the AA 4.8w seems to suggest that it works fairly well. Humm.

It makes sense to me to have a maintenance option over a 'flat battery & revive' solution - but it needs to work of course may need to test...although the jump start option would get us out of other problems.

 

[profdraper]

Anywhere except super low or 100%. 50-80% is current practice.

 

[apzs]

I've left mine in the airport car parks for a week and left it at about 70%. Been perfectly fine, not a single percent drop. Came back started and drove back home

 

[MG steve]

Does putting your cooling or heating remotely charge the 12v battery?

 

[yellowking]

We came back after a month in Thailand and mine was just fine. Drove it straight away no issues

 

[tkmaxx5]

This is a random related question, if your 12V battery goes flat would plugging your home EVSE remedy that, or does there need to be some juice in the 12V to begin the charging process?

 

[Coulomb]

or does there need to be some juice in the 12V to begin the charging process?

There needs to be some juice in the 12V to begin the charging process.

Before you can do anything with the big battery, you need to close the contactors inside it, and for that you need a little energy from the 12V battery. A lot of computers wake up at this point, so they need some 12V energy too. Ten seconds after plugging in an EVSE or a DC charger, the car's DC-DC can take over the 12V duties, including recharging the 12V battery.

It's worth remembering that allowing the standard lead acid 12V battery to go totally flat, even for a day or so, pretty much ruins it. If the time it spends being totally flat is short, it might recover enough to work for a while, but it will be wounded, i.e. it will have suffered some degradation, in other words, a loss of capacity.

If you had to leave an EV at the airport regularly and can't rely on AC power for trickle charging, or a solar panel, you could replace the lead acid 12V with an expensive LFP model, which has a battery management system that can save it from such degradation. Then a portable recharger in a fireproof bag could get the car going again after many times when the 12V ran flat, and the LFP battery should survive this punishment.

Of course the best solution is for the car itself to automatically charge the 12V battery as needed, at least until the main battery reaches a low SoC limit. Out If Spec Reviews did a video on an EV abandoned for something like 10 years. The 12V battery was toast, but the traction battery was still at 30%, having charged the 12V battery as needed until the traction battery reached 30% SoC itself. There are a few posts on this forum about it, which is how I heard about it. But I suspect that MGs don't all do this. My ZS Mark 1 in particular never seems to charge the 12V battery. Maybe I never leave it undriven for long enough.

 

[DBedford]

No issues what so ever with our left at a friends while we were on holiday for a week.