Renters Dilemma..... Charging the battery... Need help!
 

Hey gents!,

I live in the city and I just bought a 2010 boxster for the weekends when I'm not working. So my car as it stands is just only used on the weekends. So it sits and of course with sitting the battery doesn't have the chance to keep a charge going. I've had Porsche test the battery and it's fine it's just needs a trickle charger. I'm renting and I don't have access to a outlet.

So........ I don't know what to do at this point. It's possible that it may just need a new battery. Since it's the original OEM. But even so the battery is only 3-4yrs old... For an OEM battery that's not too bad. Is there any device anyone can think of like a lithium batter pack that you can charge a battery from or something. I'm desperate at this point since I just don't know what to do. I'm pretty sure the car is grounded well I still have the Porsche Warranty.

Thanks a ton guys for any suggestions.

Send me your address. I'll come over and charge your battery for you during the week. No charge. Just leave it with a full tank of gas.

Look for a solar powered maintainer that uses a small solar panel set up on the dash to generate power.

How about using a car battery to provide the storage power, then use an invertor to convert DC to AC, then use a battery maintainer to keep the battery in the car charged. Then, turn everything around and re-charge the storage battery from the charged car battery on the weekends.

(you know I'm kidding,right?) :)

The solar powered idea isn't bad. I've seen them used to keep batteries on car trailers charged up ( to power battery operated winches).
I only drive my car about once a week during the summer and I never have to charge the battery during the driving season. In the winter I use a plug-in Porsche charger that connects into the cigarette lighter socket to keep the battery maintained. So if you drive it every weekend, you'll probably be OK without a charger.

You don't say where you live but ideally a trickle charger is optimum. Failing that my 2001 Box base sits for a week at a time in the winter uncharged in -20C or around -5F when we go away on holidays a couple of times in winter.

In the 2.5 years of ownership the car has never failed to start after a week of sitting. Whether this applies to your 2010 I don't know. I have manual key only so getting into a locked car is not a problem and as long as I have power I can get into the front trunk. Obviously a good long run before you put it away and after you are done is recommended. Trust this helps. :)

Solar tender would be ideal in your situation.

However, if your battery is weak or dead after a week, it's about time to replace it (assuming no parasitic draw).

No access to an outlet. Hrmm, is a really long extension cord feasible? I've worked in hardware stores before and there are some really long extension cords. Otherwise like the above guys said a solar powered charger may be a solution.

Actually, you know, you might have something there, except use a booster unit with a 12V power port to power the maintainer, and re-charge the booster unit from an AC outlet while you are driving the car on the weekend.

So crazy, it just might work....

Guys thanks soooo very much for all the help! The solar charger might actually work! Although I always try to cover my car when not is use I'm sure I can hook something up. I was hoping that there was a lithium battery that you could charge in the house and when it's done you just plug it into the cigarette lighter socket till it drains out. Wash/rinse/Repeat.

I think i'll give that solar panel a try. I'm hoping our cig lighter allow for the reverse charging while the key is not in the ignition.

I've been considering a trickle charger myself, as my car sits over two months sometimes between drives and then gets driven a lot for a week or two (it lives at my vacation house so there are many reasons for this.) Point being here, that my S starts right up every time no problem, and is stored over 15C and on average over 20C with no charging in the storage period. I don't know the age of the battery, but it clearly holds a charge very well.

The solar trickle charger is your friend as others have commented.

I have tried this as simple solution. You need a diode in that cord otherwise the charge will eventually go the other way.....and blow your cig light fuse. If your car battery is really low you may blow the fuse right away anyway. So this did not work for me. I have a gel cell though

I only drive weekends. I travel a lot, sometimes two weeks at a time.
Never had the battery die on me. I think you need to be at like a month+ without turning the engine.

Maybe look to see if one of those jump packs have a low trickle setting? Even better would be one that can hook up to your cig port.

Plug it in at home to fully charge during the weekend then use it to trickle charge during the week.

I didn't a think a solar panel under florescent lights would have enough umphhhh to counter act the parasitic drain so i didn't try it. A car cover complicates this aswell...someone may walk by and snip snip your panel is gone

What i did try:
Locked a plastic tool box to the car
Placed a heavy duty computer back up module in the box
Cut plug sized hole in box
Plugged a ctek into the computer back up box through the hole
Plugged the ctek into the cig lighter
Rotated charged battery backups (2) into the box often enough to maintain some sort of trickle charge

This might work for a regular lead acid but i have feeling that this sulphated my gel cell. Not sure but they really need a high amp charge.
For winter storage i pull the battery and plug it into a wall

Inverters are already built into these power pack devices

Yeah i'm looking on amazon and a few questions pop up all the time.

1. Can we use the cig Lighter as a charger without the key in the ignition.

2. I'm struggling to find a alternative to the solar solution. A battery pack that the car can draw from. I keep reading discriptions on amazon, but none of them say you can use it like that. They all look like you need the wall socket to draw from. Basically all I want is to charge a battery pack in the apartment via wall socket then when it's charged you bring it down to the car and charge it from the battery pack.

3. 2010 boxsters I believe use a Wet battery.. So, i have no clue what charger would be okay for that. A lot i see are just lead/acid based.

#1: Yes.
#2:Forget finding an alternative to solar, you are slowly turning this into physics experiment for no apparent reason.
#3: Correct, you have a flooded cell lead acid battery, so just about any maintainer would do the job.

Here is one I found in about 10 seconds on Amazon.com for about $20:

http://content.westmarine.com/images.../11460334N.jpg

Totally agree with you JFP. I'm definitely looking into the solar route. I did want to keep the car cover on. Also, my car is under a car port. So getting sunlight could be difficult although I hear it gets decent power on a cloudy day so maybe it'll work it's worth a shot. If there is a batter pack alternative though. I think that would fit the bill better. I'll try the solar though for sure.

I would suggest having your battery tested. It's approaching 4 yrs old and factory batteries can die anytime after 4+ yrs.

Also, do you lock your car when you leave it during the week? May seem like a silly question, but your car will go into hybernation mode after a period of time with it being locked vs staying in "awake" mode if it's unlocked. Awake mode will draw more power from your battery. And back to the silly question - a member on P-9 always left his car unlocked in his rear driveway with the key "hidden" under some stuff on the passenger seat. Until it was stolen.

Thanks Husker.

Yeah I just had the battery tested at the dealership. It's a good battery according to them. A good thing since and are you sitting down? The price for a new OEM porsche battery is.............

$480.00 installed. Not covered under warranty

My old lotus was half that cost lol. Even when i had my cheapo Mercedes it's was half that.