rawky

A mixture of winter cold and short journeys has meant that my 928 has died on the drive again, is there anyway (apart from trickle chargers) to keep the battery charged. I realise that the cold is one of the main factors in draining the batteries, is there maybe a way of heat insulating the battery? ANy other suggestions welcome...

Nightfly

I'm using a VW beetle solar panel charger, you can get them on ebay for about $20. Seems to work fine. Just lay them on top of the cargo cover, or put a box of some kind in the back under that big rear window so the sun can get to it.

jon928se

I know it has been cold in the UK recently. But not Ice road truckers cold.

Cold doesn't kill batteries unless it gets cold enough to freeze them and once the engine is running and the alternator is charging the current from charging will keep them warm enough to charge.

Whatever the temps, unless it's in the minus twenties or worse, short journeys meaning multiple engine starts and with the lights and probably heated rear window switched on will take more out of the battery than the alternator can replace. A voltage sensing trickle charger is the simple answer - just plug it in everytime you're at home. I have both of my 928s connected whenever they're at home - wired in a gold plated phono socket to the permanently live supply to the seat height adjusters, socket located in the hump under the handbrake - just plug it in whenever a 928 is int he garage. Easy. No more flat batteries.

Got fed up spending £100/year on batteries.

rawky

My battery hasn't died, but isn't charged up enough to start the engine, are you saying you have a fast way of plugging in the charger without removing spare wheels, compressor, etc.? What is it?

WallyP

Porsche put a battery terminal under the bonnet for just that purpose...

If you want it even easier, put a fused lead from the jump start terminal and combine with a ground lead, then run the pair to the grille area, and put a phone jack, phono jack, or any other slip-fit jack on the end. A matching plug on a battery maintainer (NOT a battery charger!) and you are good to go. The slip-fit plug lets the maintainer stay in the garage when you back out without remembering to unplug the system.

If you really want the battery to last a long time, you need to add a desulphator to the system. One approach is shown here:
http://home.comcast.net/~ddenhardt20...esulfparts.htm

A UK source:
http://www.courtiestown.co.uk/batter...esulfators.htm

If you want a charger and desulfator in one commercial package:
http://www2.northerntool.com/auto-re...tem-167988.htm

None of these are recommendations, just ideas to get you started.

RngTrtl

When you buy the trickle charger it should come with a set of terminals that you mount to the battery terminals. These in turn plug into the cord on the charger. I have run mine so that the cord just barely pokes through so I can plug it into the charger real quick and easy. I got one similar to the one below and use it all the time. Best 20 bones I ever spent. I have had my 928 for almost 4 years and am still on the same battery that was in there when I got the car. You can see the terminals that I was referring to in the lower left of the picture.

WallyP

For long-term usage, a "battery maintainer" is much better than a "trickle charger".

A battery maintainer cuts off completely when the battery is fully charged. A battery charger, even a trickle charger, will over-charge the battery, shortening its life.

Alan

I believe a battery maintainer and trickle charger are in all practical senses the same thing - I'm unaware of trickle chargers you can buy today that do not have voltage & current sensing just like any battery maintainer - so I use the term interchangeably...

I'd suggest you consider a block heater as well - this will significantly ease what will probably be your coldest start every day saving juice that you will otherwise need to recharge. Try to avoid heavy use of the rear screen defroster if you can - e.g. help it. by cleaning the screen yourself mechanically..

You can integrate the whole battery maintainer and have a 110V plug in for the maintainer and the block heater - I'd do this if I lived somewhere cold and had to leave the car out.

Alan