sunnyr

So my battery is on the last throes of death. I got a Ctek charger and the cigarette lighter adapter and would like to use it. But the manual says, to charge the battery, you have to remove the battery? Here is the relevant portion -

1. Pay attention to all warnings and follow instructions
that come with your battery charger.
2. When charging, ensure adequate ventilation.
3. Remove battery.
4. All vent caps should be open.
The fluid level should meet the indicator mark
in each cell.
5. Ensure that charger is switched off – danger of
short circuit!

The gazillion warnings in the manual about the battery blowing up makes me think I am dealing with a bomb and not a battery. And there is also this thread about teh battery really blowing up. From reading it, it looked like the explosion happened from hydrogen buildup during trickle charging.

So what is safe way to use the charger? Do I have to remove the battery, in which case I rather not. Or will just leaving hood open and removing the plastic lid do? Should I be disconnecting the transparent tube (vent tube)? Is it safe to trickle charge with a car cover on?

Thanks for any advice.

Spyerx

Plug in to cigarette lighter, turn on charger, done. Your battery is vented already assuming you have a little tube going from one side of the battery.

I've been doing this for a couple years now and there are others that have been doing for much longer than me.

J. Kid

Before I started driving my cars year round I did the winter storage thing and had my fun car on trickle charge continuously via cigarette lighter all winter with car cover in place. In addition to what spyrex said when you take it off trickle remove the outlet plug 1st then the cigarette lighter attachment. I never had a problem with my battery using this routine for 3 years and the battery was old when I bought the car.

mooty

how often you drive it?
i use full size batt
i drive once a month, sometimes once every other month. never used trickle charger ever. always fires right up.

sunnyr

I probably drive it once in 2-3 weeks, at least for a short drive. But the problem started after I forgot the keys in the ignition overnight once - big mistake - it is almost dead since. I plan to get a new battery, but was curious what is the right way to trickle charge.

brake dust

I would replace the battery. Why take
the chance of getting stranded for 200 bucks.
Use the trickle charger preventative on new battery.

911rox

Ensure electrolyte levels are right, plug in your charger and charge. As others have indicated, battery is ventilated... I charge using a ctek but don't leave it plugged on all the time... 1 day charge every fortnight. Hood closed, tube connected, alarm armed (locked)... 3.5 years later and no issues or mishaps ...

When I switch off and disconnect, I leave the car to sit for half an hour before starting (if I plan to drive) to allow any built up hydrogen in the battery to vent... Apparently they can explode if the car is started immediately after charger is switched off and electrolyte level is lowish exposing the plates within the battery which can result in a spark, igniting gases in the battery... Thus the warning about ventilation and plugs off...

LVDell

Which CTEK do you have? I have a 3300 and it states NOWHERE in the manual that the battery is to be removed. Further, the CTEK3300 isn't just a charger, but also a maintainer so you can leave it on long term. I have been using CTEK3300 chargers for a decade now and the main reason I like them is the maintenance feature so it's no longer charging when the battery is at full charge. It's truly a "set it and forget it" unit.

Nizer

Why risk messing with chargers? Just disconnect negative lead and leave it as long as you want.

LVDell

Battery will still slowly drain with battery disconnected. As me how I know. One charger short and tried that approach to a car that sits for months at a time. Also, not a good idea to completely remove power from the car with all the electronics it has (read that somewhere).

sunnyr

Yes, good advice. I do plan to get new one right after Christmas. Just want t make sure it starts up then.

Thanks Chris for the detailed instructions.

Dell, I meant the Porsche manual, not the Ctek one.

Steve W

In the lowest power state, with the doors locked, the car has a parasitic drain of about 0.8 Ah/day. Leaving the car parked for three weeks discharges 18 Ah out of the battery. With a 40 Ah battery, that is about half of the total capacity being drained out. Each one of these deep discharge cycles kills the battery; 50 of these and it's junk. Leaving the doors unlocked triples the parasitic drain. Keep it on a quality maintainer. Wire the connector to the battery terminals, and connect it there with the front trunk open. No risk of hydrogen gas explosion ever with it open. Hydrogen gas is really only created if a charger continues to pump excess current into a battery when the absorption capacity of the battery has already been reached, the excess current goes into boiling the electrolyte to expel the energy. Force pumping a lot of current with a high power charger to a battery in a closed compartment is how you cook the battery and risk an explosion.

The Mick

When I picked up my Porsche charger the parts department told me to use it in the motorcycle setting with the doors locked.