Charging in a powerless garage

Hello, what solution would you propose to keep the battery topped up in a garage with no access to power? Running another larger battery in serial? Automated generator? Is there such a thing? Open to ideas. The car is a 996GT3 2003. Thank you. Richard

I think the second battery is your best bet, get the biggest you can find, 120amp/hr? Should extend life for 3 weeks or so. You could get a solar charger but you would need one about 1m square to actually work and they aint cheap!

A good selection of solar chargers here https://www.sunstore.co.uk/product-category/solar-panel-kits/12v-solar-battery-chargers/ I have used solar in the past and it did the job pretty well. If you go down that route make sure you have a charge controller between the panel and battery.

Welcome Richard! I have a 10W solar panel and controller sitting in my garage, from when I used to store my 911 in a barn without power. It just about did the job, but I reckon 20W would be better. You are welcome to have it (inc P&P) for a £15 donation to charity. PM me with your email address if you want to give it a go.

Thanks for the replys. In reverse order. The garage is a 3/4 minute walk away and with where it's situated, if the alarms kicks off it'll disturb others but not me. Solar therefore sounds the best solution but I'm renting the garage in a locked compound which currently means I don't know yet if I can fit a solar panel. May I come back to you on that? I like the idea of a 120amp/hr battery but then getting that back, charging and resintalling I'm sure will become tiresome. Just a thought, has anyone tried a battery isolation switch with the alarm separately isolated (and battery flattened)? Has anyone got thoughts on that idea or gone down that route? Don't mind about radio settings as once going it's too noisy to hear anything but the fabulous engine. Oh, and thank you for the welcome ????

I’ve also used a solar panel. I can’t remember the specs but was around the size of an A3 sheet. I mated it to a controller and in worked okay. Hope that helps, John

Thing is, if you disconnect the battery there is no way of fully locking the car. You can lock the driver's door with the key, but not the passenger door. The alarm and central locking unit are all in one unit, and you can't have one without the other. Even disconnecting the battery isn't straightforward. The alarm siren has a backup battery inside. To disconnect the battery without the siren going off, you have to switch the ignition on before disconnection.

That's interesting, so if I had an ignition isolator switch fitted as long I turned the ignition on before pulling it out, the alarm would not go off. Yes, I would have an unlocked car. The car though will be in a locked garage, in a restricted locked compound with no power to start. My thinking is that if they were that keen to steal it, alarm or no alarm, locked or unlocked, it's going anyway. Really appreciate any further thoughts / feedback. Very useful conversation.

The alarm siren needs a Terminal 86S feed before disconnecting the battery, otherwise it goes off. Terminal 86S is activated when you switch the ignition on, and de-activated when you remove the key from the ignition switch. So, basically, switch the ignition on, then off, but don't remove the key (or just leave the ignition on). Then disconnect the battery, after which you can remove the key. Before re-connecting the battery, it is best to turn the key to the on position, then off, and leave it in the ignition switch until you have fitted the battery. Bear in mind that if you have electric lid releases you can't easily open the front compartment. You have to rig a 12v supply to the terminal in the fuse panel. If that doesn't work for any reason, you have to use the emergency lid release cable, tucked behind the front wheel arch liner. Is solar charging beginning to sound more attractive?

Hi, thanks for the response. Did the controller come with the solar panel? Cheers Richard

Yes, will look into solar panels. Thank you. Will call my local Porsche specialist tomorrow to likely rule out an isolator switch completely. Thanks slot for your detailed response. Has helped a lot. ???? Cheers Richard

Richard (H) - do you know if this trick with the ignition (or similar) works with the 993 (PA1000) alarm? - when I disconnect my battery I and my neighbours have to put up with my siren (the original siren had a key switch that silenced it but I had to replace the siren and on the latest version the key switch controls internal battery charging) Thanks

I haven't tried it on my 996 yet so don't know. It kinda makes sense and given the background of the person who provided the suggestion I have no reason to doubt. Give a go and let me know? Cheers Richard

I have a garage without power. In the end I bought a new Bosch battery for the car. It's held its charge for past few winters and starts first time - although I will start and drive the car over winter. As backup I bought a battery pack to jump in the event of no charge. As an aside the starter lead (top of engine) can lead to poor or lethargic starts, more noticeable when hot. I swapped this lead and ensured earth straps are good.

Hi Mark. Simple answer is that I don't know. I have a PA1000 on my Carrera, but I have never tried it. I turned the key switch on the siren, which stops it sounding when you disconnect the battery, but it still goes off when you reconnect it! Wierd that the new siren switch works differently - I can't see the point of it controlling the backup battery charging.

The latest update. I spoke to Jaz Porsche (specialist nearby and in the outskirts of St Albans). Asked about the options given above and they said first they would want to know why the battery is draining so fast. They say the alarm draws power and some trackers do. Therefore before deciding on the best solution, what's causing the problem. Makes sense to me so will book the car in over the coming weeks and see what the conclusion is and update this post. Like the ideas suggested as it means there are work around. Cheers Richard (S)

Alarm, immobilizer, radio, tracker clock...............in the cold I wouldnt want to leave any car unused for more than 3 weeks at most, realistically less to be certain you will start on the button. How fast is your battery draining?

The battery drains sufficient in a week for my tracker to email me with a warning and sometimes for the alarm to go off. Not long enough for an occasional weekend car.

Hmm! Time to try pulling some fuses Richard to see if you can locate the source of the current drain. If the battery's a few years old I'd be inclined to fit a replacement - continuous discharging and recharging the battery won't be doing it any favours. Jeff

What about a trickle charger connected to the live cigarette lighter socket? I believe that's possible with the CTEK (other brands are available [ ]) and is what they are designed to do... You should be able to permanently fix the connectors to the battery terminals and then when you leave the car in the garage connect them to the trickle charger and plug that into the live socket. There is a cut out in one of the door seals to allow a cable to run and then drop it down under the top of the frunk near the wiper blades.

I think the answer to your suggestion, James, is in the title of the thread.....[ ]

Hi, Thanks for the responses. Without going into detail I will let the specialist do the investigation. While there is a cost, the practicality is a lot easier. The car is on a Ctek all the time now but I want to park it closer to me but more importantly be park it in a garage so that after each use I do not have to clean it (put a cover on afterwards). So will go ahead with the investigation, then see if I can install a solar charger, it not it will be the ignition on and undo the battery. That's the plan at at least. I'll update this post with the results but it'll be a few weeks away. Thanks.

May I add a further question after a bit of thought. The 996 currently sits on the recommended Ctek. We all choose Ctek becauseof it's cycling, protecting the battery and alternator. How does a solar charger cope with this aspect of battery / alternator longevity? Thank you.

With one of these.. https://www.sunstore.co.u...ar-charge-controllers/

Thanks for that. On the case (Sunstore). Cheers, Richard

I have a garage a 15 min drive from home for my 996 Turbo - I bought one of these and using a c-tek charger charge it once week - seems to work perfectly. https://www.goalzero.com/shop/power-stations/goal-zero-yeti-400-portable-power-station/