I have a solar charger rubber suckered to the garage window 4ft opposite the house wall, facing north. The blue charge light still flashes and keeps the motorbike battery at 13.4 volts all year round. They don’t need strong sunlight, any light will do.
Another thought, if leaving your car away from the usual parking home for weeks, do the insurance have to be notified? They usually ask the question when applying for insurance, “where is the vehicle usually kept” and small print usually says something like except when away from home (holidays) and ex number of days.
On the subject of the battery, if you have breakdown cover get them to come out to get you started if needed. Surely there should be enough juice left to keep the radio active if not enough to get you started.
The solar charger is only a £10 ish cheapo one off ebay and the best tenner I’ve ever spend. It came with crocodile clips for the battery and a cig lighter plug. Obviously you won’t be able to use the plug because they’re on the accessory key, you’d have to use the clips on the battery. My bike has a permanent live socket which is great and I don’t need to remove the seat to access the battery. Note, these chargers will only maintain what’s already in the battery and prevent them from going flat from seepage. Advise you fully charge the battery before going away and make sure the solar panel suckers aren’t going to fall off the window which can happen after a few days. A spot of washing up liquid on the suckers helps.
The one I have is probably similar to yours, special offer from Farnell wholesale, who I used regularly when in business. Had it for several years now, never used it, as I couldn’t figure how to put it in or in the car, but your post makes me realize I could put it on the rear parcel shelf, except I have to work out how to fix it, or it will get slung around a lot when I corner. The car is always on the drive, or a parking lot if travelling. Nose out, facing south, so the rear window is north facing. Your post helps no end!
I’m back again with an interesting update…decided to phone the mazda dealership where I bought the car from as it was 2 1/2 years old when I bought it last year and the dealer gave me an extended warranty. Explained the situation to the Manager and he said that not many people actually use a code and the code is not factory set so he would be surprised if, after disconnecting the battery I will get a problem, but if I do, phone them back and they will be able to supply an over-ride code, but in order to do this I would have to prove that the car belonged to me and forward documentation as they would have to apply for the code on my behalf. Even though they remember me I would still have to provide documentation for security reasons.