Technical Fiat MK2 Car Battery & Solar Charger

[deeinlondon]

I don't drive very much as I live in London - usually it's a few miles drive to the tube station and then train into London.

I find if I don't drive my car for about 2 weeks the battery is flat.. is that normal?

There is no added car alarm and I've installed a cut off switch for a LIDL Made Car Radio so it shouldn't add to the drain - is two weeks too fast?

I checked the battery and it was above 12V and with the car turned on and engine running reading 14V - is that normal? Battery is Bosch from Costco, no idea how old it is - over 4 years I'd say.

I have a CTEK charger and use that quite often, always before a big car journey which isn't very often but now I go camping one every few months and drive about 200 miles round trip. So charge the battery before I head off just incase.

I just found a Solar Charger from Maplins I had inthe loft, bought maybe 15+ years ago for my firs Punto - thinking of fitting that to the car but I read the volts and it was giving out 20V in bright sunlight, is that too high?

I believe I need to hard wire it into the battery terminals as the cigarette lighter is cut off when the key isn't turned. Any tips regarding this? I was thinking about buying a cigarette light extender and then cutting off the end and fitting to the battery with the solar cell placed on the rear parcel shelf 24/7

 

[g8rpi]

@deeinlondon

The Voltages you have measured are about right, no obvius battery or alternator fault.
If the Maplin solar panel was sold as a car battery charger it should be OK. The 20V would be off load. The best idea is run in an extension "lighter" socket. Connect it directly to the battery, but you MUST put a fuse (2A is OK) in the positive wire close to the battery connection. use an insulated fuse holder, look at Maplin's MX15R or RC71N. Make sure not to run the cable over any sharp edges or parts that get hot.

Robert G8RPI.

 

[AndyRKett]

Be wary of using a very old solar charger a lot of the older ones did not have protection against reverse currents, this means when the sun isn't on the panel or over night the panel acts as a load across the battery and will be a drain it's self, these days you can get a similar and probably more powerful panel for £10-15

As for the battery lasting only a couple of weeks, this is pretty normal for a Punto

 

[Southsea]

I too have a Ctek charger they are great. I stored a Volvo for four years using one. I have also tried the solar panel on caravans and cars, the,y do not work on sun rather UV but they cannot be relied upon to service your battery end of.

 

[g8rpi]

I too have a Ctek charger they are great. I stored a Volvo for four years using one. I have also tried the solar panel on caravans and cars, the,y do not work on sun rather UV but they cannot be relied upon to service your battery end of.

Solar cells do not work on UV, the efficency falls off below 400nm (not least due to the glass cover) Peak is in the red/near infrared.
A typical car unit won't charge a flat battery, but it will supply power to support the fixed drain and reduce the discharge of a charged battery.

Robert G8RPI.

 

[Ziggy122]

A battery not lasting a forenight....

To me thats crap, never had that issue

If you go into the guides
A1ant did a guide on paracitic drain testing

Or look up
Eric the car guy - paracitic drain test on youtube

The puntoa battery aint very big
But id happily leave my month and be very co fident itd start

Ziggy