Multiple batteries?
 

Hello all

My car is pretty much a weekend / dry weather vehicle. Consequently it tends to spend a lot of time stood on the drive during the winter. This forces me to have to keep changing the battery, on the car and out on the drive.

I don't want to leave the car with a disconnected battery as I want the alarm to still be functional.

Would there be any problems with connecting two batteries to the car in parallel (positive to positive, neg to neg)? In theory, in my mind anyhow, this would double the capacity of the system.

I realise this would then take twice as long to change when needed but as I have 2 chargers I can do 2 at once if I separate them.

Do I have a win win here, twice as long to discharge but the same amount of time to recharge?

I suspect things are not that simple but please let me know what you think.

I would certainly not run the car with this configuration.

Thanks Frank

Solar battery charger left on the dash/ window and connected to the 12v Cigarette lighter.

Are these things good enough to make any kind of an impact in the winter?

Hi Frankie

I'd recommend fitting / using a CTEK charger / conditioner with comfort charger, you can leave it connected as much as you wish and it automatically shuts off any functions if the battery doesnt need anything . . . .

Charger:
https://www.ebay.co.uk/itm/New-CTEK-...kAAOSw-0Jdgf6K

Comfort Indicator Panel:
https://www.ebay.co.uk/itm/CTEK-COMF...sAAOxyW7tRhiV5

You can leave the charger in the boot and run a power cable to it and still close the boot for security as the lead will run through the seal ok

I actually have a MXS 5.0 and an MXS 10. These are the 2 chargers I was planning to use to change both batteries. I also have a Ctek device that trsnsmits battery voltage via Bluetooth. I can even pick that up in the house.

Not sure I feel comfortable leaving a 240v power cable running down the drive 24/7 although that would be the perfect solution.

My own stupid fault for buying a house without a garage. Or is it my own stupid fault for buying a car and not using it?

Arctic-grade cable (yes, there is such a thing - typically blue insulation, sometimes orange) and a plug-in circuit breaker and it should be fine whatever the weather. Anywhere it might be a trip hazard, mark its path with something bigger that people have to pay attention to - pot plant, boulders, etc ;)

For what it's worth, mine seems quite happy with a Halfrauds 2.4W/12V solar panel (£25) combined with the (essential in my view) OBDII plug (£10). The 12V sockets front and rear always tend to be slightly hit and miss in my opinion and the crocodile clips won't be viable in mine due to the lack of ski hatch. The OBDII plug just works and the terminal is always live. Reverse polarity protection too.

My recent battery woes detailed here:

http://forum.a8parts.co.uk/showthread.php?t=15074
http://forum.a8parts.co.uk/showthread.php?t=15132 (related thread from Nognar)

There is a larger 6W panel available but that's the size of a house.

The Aldi one I highlighted above is an excellent trickle charger, been using one of mine for over a year now..and at £12.99 well what's not to like +++ Just bought another 2 recently as No 1 son has buggered off doing some round the world travelling stuff+++

Don't bother with it. I had 2.4W and 13W solar chargers and in summer 2.4W did not make noticeable difference, 13W was taking up 2/3 of windscreen and while it was slowing down discharge it could not keep battery fully charged. In winter there is less light so less power and less hours that you have sunlight so results will be much worse. If it says 13W, it's 13W only max rating in best case scenario if it's facing sun at 90 degree angle in direct bright sunshine in the middle of summer. Cloudy winter day not in optimal angle and behind windscreen you will get maybe 0.5-2W. Depending on equipment you probably need about 2W to run it. So for couple of hours a day it would stop discharging but most of the time battery would still be discharging.