ronnie993tt

I'm a very sensitive guy so please be gentle if this is a stupid idea (Clive!). Lacking an outlet in your underground parking, why not plug a trickle charger into a Power Box sitting in the back seat instead? You can then re-charge the Power Box every month or so, and put it back in the car. You never even have to unplug the cigarette lighter end.

Imo000

Sounds logical, give it a try.

Turbodan

if it is in your garage (not underground) you can purchase an inexpensive solar trickle charger or run an outdoor extension cord

ronnie993tt

Now there's a great idea if you have sun access. I'm heading over to the Chick'n Deli for some beers Danny. Tell the bride you have to go visit a sick friend. You won't be lying. ...I'll have a cold one waiting for ya....

Jaak Lepson

The powerbox would last for about a day or so. You would have to charge this up dailey if you wanted to constantly charge/maintain it. A battery will hold a charge for a while depending on the load on it. One can do this once every couple of weeks depending on what is still connected such as the alarm to keep it topped up..

ronnie993tt

If the battery would normally go dead in a month with the alarm system on, why would the power box not last much longer?

petee_c

1. why not bring the battery up to your condo?

2. it would be more efficient to just hook up your booster pack to the car in parralel and take out the inverter and trickle charger out of the equation...

(you are taking 12v DC power, converting it to 120V AC, and then back to 12V DC power to plug into your Porsche.....)

Each step adds inefficiencies to the system.

What happens if you just unplug the battery from the car?

P

ronnie993tt

Very bad to power down any car with an ECU. Apparently ya loose the programing. In fact if you remove the battery you should plug in a trickle charger beforehand to maintain programming.

aviography

From purely technical perspective, this is only true for any parameters specifically to your car stored in the memory requiring power to maintain, the actual ECU programming code (i.e. firmware) should not be affected since they will require electrical power to erase, i.e. it has to be a deliberate software command with electrical power applied to cause any code to be lost.

It's not a bad idea in theory, however you would be back to square one if you have even a momentary power outage, unless you plug the trickle charger into an UPS (uninterruptable power supply) to maintain constant 110 VAC the trickle charger requires.

911 Rod

I scratch my head ever time this comes up.
I do nothing and my cars starts faster than it does in the summer.
Is my car that much of a relic?

Jaak Lepson

The charger has a constant draw on the powerbox of 0.5 A as listed on mine. That's a constant draw on the box 24/7 and as the voltage on the box drops ... the current draw will rise. Think of how long your battery lasts with a trunk light left on? You will get maybe two days at the most out of it which may be enough every two weeks to keep your battery up to snuff.


ronnie993tt Very bad to power down any car with an ECU. Apparently ya loose the programing. In fact if you remove the battery you should plug in a trickle charger beforehand to maintain programming.


Not true. Once the battery is reconnected the ECU relearns the programing/operating parameters after about 100 km of driving. The EPROM still keeps the vehicle parameters "on file". Look in your manual as to how long one needs to drive for the ECU to re learn YOUR driving habits. It is always updating it's self. On the older cars you will need to keep the radio code written down somewhere.

Jaak Lepson

I always charge the battery up to 100% before I put it in storage. Once there I disconnect the neg terminal and cover the car. In the spring I reconnect and it always starts up. In storage around 15th of Dec and out around April 1st.

When I get it home, I always connect a charger to it and bring it back up to 100% (ACT type, smart charger). I have done this now for 8 years with both the 951 in past and Beepster last two years. No battery issues!

One can bring the battery to the condo and charge it up once a month. Hard to steal the car with no battery attached.

ronnie993tt

Thanks guys. Great feedback. I'm going to be storing the Z - no ECU issues - in a condo lot so I'll just yank the negative terminal and hope for the best.

Imo000

All I do is pull the negative pole off and that's it. When I want to start it, I reconnect it and crank it over. If it sounds like there isn't enough power, I just hook up a charger for a few hours and that's it. This only happens if the car sits for months. Otherwise it fires up every time. My brother's 928 S4 used ot have a slow power drain and had to disconnect the battery or it woudl go flat in 3-4 days. Never had any issues with the ECU. The adaptive learning gets the proper parameters fairly quick.