Thank you all so much for your advice. I am looking into the solar charger as I have nowhere to plug the car in regularly. Question to those of you who use one - does it charge via the charge point in the car? Can I just plug it in, leave the solar panel on the dash and let it trickle away?
I could use a plug-in as a one off through the front door/window but not on a regular basis. I had to move it forward just a few feet the other day to fit a mini-bus behind it - long story - had to just push it as it was as dead as a door nail.
Unless it is getting on for a metre square, a Solar panel will not have enough welly to recharge a flat battery in the UK and inside a car, but a smaller one will cancel out most of the dark current being lost by a charged battery.
If you canât put the car into a garage and conveniently charge it with a Smart mains plug-in, you need both a plug-in and a solar.
Now your battery is flat, take it out of the car, bring it into the house and connect it to the new mains plug-in Smart charger you are going to have to buy.
As has been said before in this thread, there are many Smart plug-ins around with a wide range of prices, but there is no point in going much above 5A, and 3A to 4A will be fine for our cars with their small batteries.
Too high a charge current over a long time (eg 12 hours for a totally flat battery) can damage some types of battery, but as long as the current it is less than about the 1/10 C rate (ie it is less than 1/10 the Ah (Ampere Hour) rating) it will be fine, and the Smart chargers are clever enough not to boil the battery.
A typical solar panel (eg 30cms square) can plug into your OBD2 port once the battery is back in the car. Here in UK its average daily output in Ah will be about equal to the losses the car has through âDark Currentâ ie alarms, radio memory, battery itself slowly losing charge.
Aiming the panel directly at the sun makes an enormous improvement to how much output it has. Snag, the sun moves.
Size of panel is very significant and this sets the maximum current possible.
Amount of direct sun on the panel is the final limit. Snag, the clouds pass over, and it rains.
Iâm using a nominal 2.5W panel (ie in tropical midday sunshine correctly aimed!) to counter the losses on my Mazda3, but I expect it is probably giving me less than 0.5Ah per day on average, so eventually Iâll need to give it the plug-in boost. In UK youâll need a nominal 5W or 10W panel to be on the safe side and average about 1Ah per day, which is a typical Dark Current loss.
With my solar panel I connect the clips to the battery, run the cable along the side of the bonnet area up through the scuttle (wipers) area and in through the drivers door (pushing it into any grooves i can find). Never had a problem.
As i said before because you battery is flat you will need to charge it properly on a mains charger first before the solar charger will help maintain it after
WellâŚwe used the battery pack to start the car. First attempt - nothing - after my husband had gone out ahead of me and opened the door with the key as the button wouldnât work. I walked out to a beeping sound and immediately thought, well it probably wonât start anyway as it thinks itâs being stolen!!! Beeping stopped we had another go, using the force start button on the battery charge pack - tada! Started. I clapped and whooped. Never been so pleased to hear a car start.
We let it run for a while and then I took it for a ten minute drive, never even left the island, as I felt so bad with it being extremely non-essential! Checked the brakes before going, and the noise changed as I was out. Weird having the windows down and the roof up! I drive with the roof down in December if I can. Anyway, I stalled the car as I was so busy listening to the brakes. I never ever stall the car. Ever. Any car. Mini-buses, big car, Dadâs car, little car. So typically on a day like today where I am being ultra careful I go and stall. It started immediately much to my relief and I intend to drive it every time I go anywhere that doesnât require a big boot! Next job is to maintain the charge using all your advice about a charger. Although it started every time no problem right through the Winter and sometimes was only being driven once a week. Cannot wait to get the roof down and enjoy it again!
The battery is typically discharging slowly due to the immobiliser (alarm) drawing constant power, my battery tends to flatten after approximately 10-14 days if the car is left unused. I have found by disconnecting (a fully charged) the battery, prevents it from going flat, but the radio and trip odometers lose there stations/numbers, but the battery lasts for months - handy if you donât have a suitable electric supply. But as this is a little fiddly and my MX5 is garaged, I do now use a CTek smart charger
Take care
Drove it yesterday to collect shopping for parentals. Started no problem. Roof down. Only drove 3 miles there and 3 miles back but loved every minute. Husband took it to pop petrol in for me as I wasnât keen on negotiating that atm. Will be driving it every few days from now on! Love that I love the car, and that I can come here and talk about it and ask questions and you kind people help me out.