Battery Trickle Charger

[johnbergen]

My 2000 Boxster S sits for about a week or more between drives so sometimes the battery runs down a bit making the cranking slow. I’d like to get a decent trickle charger, any recommendations? And so that I don’t have to leave the front hood open (the car is kept outside in the driveway with a good quality car cover on it and I’m in California so weather is mild) is there a simple way of routing the power wire through the body without needing to drill a hole? Maybe though an existing hole with a rubber grommet? Thanks. JB

[LittleBastard]

I’m a fan of battery tender brand.

We use them on all of our cars and motorcycles

[tonythetarga]

A week or two should not drain the battery enough to slow crank. My Cayman sits for 2-3 weeks sometimes w/o a tender and starts right up. You might want to check your battery or clean the terminals. Could be time for a new one.

[JFP in PA]

Originally Posted by johnbergen

My 2000 Boxster S sits for about a week or more between drives so sometimes the battery runs down a bit making the cranking slow. I’d like to get a decent trickle charger, any recommendations? And so that I don’t have to leave the front hood open (the car is kept outside in the driveway with a good quality car cover on it and I’m in California so weather is mild) is there a simple way of routing the power wire through the body without needing to drill a hole? Maybe though an existing hole with a rubber grommet? Thanks. JB

Your Boxster came from the factory with an indentation and notch at the bottom of the driver's door (just below the outside mirror) that is specifically for running a cord into the car for a battery maintainer. The car is also wired so the cigarette lighter plug is always hot so you can plug the maintainer in there, run the wire out under the door, close, lock, and arm the alarm while the maintainer is plugged in in a weather tight manner.

[911elektrisch]

Originally Posted by johnbergen

My 2000 Boxster S sits for about a week or more between drives so sometimes the battery runs down a bit making the cranking slow. I’d like to get a decent trickle charger, any recommendations? And so that I don’t have to leave the front hood open (the car is kept outside in the driveway with a good quality car cover on it and I’m in California so weather is mild) is there a simple way of routing the power wire through the body without needing to drill a hole? Maybe though an existing hole with a rubber grommet? Thanks. JB

I Second what Tony said. Check your battery and terminals. That being said I have a factory Porsche battery maintainer lying around somewhere that plugs into the cigarette lighter as mentioned in the previous post. PM me if you're interested.

[M. Murphy]

My 98 base spends the winter in a Car Jacket bag in an unheated garage. I have been removing the battery , putting it in the basement on a Stanley battery maintainer. Would it be safe to store it in the jacket with the maintainer on the battery in the car? I am concerned about long term build up of hydrogen gas in the bag, it is very flammable.

[mikefocke]

Used to live in the DC area and my car would hibernate for weeks in the winter sitting outside with a Noah fabric outside car cover over it and a battery maintainer connected to the lighter socket and with an extension cord running through the door in the notch JFP described above. There would be days I'd brush off 6" of snow and remove the cover and just disconnect the extension cord leaving the maintainer sitting on the passenger footwell just so we could go out and play. Started every time but then I was sure the battery was a good one. Get it load tested.

[tonythetarga]

Originally Posted by M. Murphy

My 98 base spends the winter in a Car Jacket bag in an unheated garage. I have been removing the battery , putting it in the basement on a Stanley battery maintainer. Would it be safe to store it in the jacket with the maintainer on the battery in the car? I am concerned about long term build up of hydrogen gas in the bag, it is very flammable.

I wouldn't change your procedure. The only battery out disadvantage is re-programming the radio code, which is not a big deal either.

[M. Murphy]

Thanks, thing is that battery is heavy. I'm kind of looking for a way around having to lug that thing down n the basement.

[tonythetarga]

Right, and the central location at the back of the frunk is not an easy reach. Same as the Cayman. Maybe rig a vent flap or a mesh vent that allows air (gas) to move out but not critters to enter.

[Brian in Tucson]

Battery Tender is a brand name. Get one, it includes everything you need to either temporarily or permanently install t he wiring in the battery. They are safe, gentle, and I wouldn't worry about hydrogen gas. The back of the hood vents pretty well.

[M. Murphy]

Perhaps I'm not explaining this correctly. The car is sealed up in a plastic bag for two plus months. My concern is that over that period of time while the battery is being "maintained" if there is enough accumulation of hydrogen gas to be a problem. Providing a vent is a non starter because the reason I seal it in a bag is to control humidity.

[mikefocke]

I wasn't exactly young or strong but by climbing into the frunk I could lift the battery out without difficulty and for a two month zip bag storage I'd do it. Gives you a chance to clean the posts and cables.

[M. Murphy]

Mike, you sound like a guy who has "been there, done that". Just hope my wife doesn't video that and send it into "America's Funniest Videos".

[mikefocke]

The battery I replaced was itself a generic replacement and not original from the factory. But after 5-6 years it gave out and so I wanted an upgrade and, not being financially constrained, went looking. I installed an Optima ordered mail order and a yellow dog mounting kit likewise mail order in 20-25 minutes discussed at the end of this page. But the same process less the special mounting plate would apply for a generic battery and P-car batteries are just batteries. The table in that blog post is really old but the basic notions are the same, any good generic battery of the right size and terminal orientation will work.

It ain't rocket science if I can do it.

[Turd]

I have a 6 year old generic battery that I plug into a battery tender if the Boxster S sits for more than a couple of weeks. The car sits in a fabric cover in a carport through Canadian winters and starts readily every month or so through the winter. I put a little hole through the car cover to run the cable through and I leave the frunk unlocked. I swear by the generic battery tender (which looks identical to the Porsche battery tender).

[Brian in Tucson]

If you're going to go big and replace the battery, AGM sealed batteries are available in auto sizes and configurations, and some are not vented so they don't outgas. The way I would do it is to charge the battery with a regular charger and then using any of the methods mentioned, keep it on a battery tender for the off season. Battery tenders are very low amperage, so charging is slow--and hydrogen molecules are the smallest in nature, so they will leak out through zippers or even plastic. I look for them at garage sales, both my Battery Tenders (TM) were less than $10.

My battery isn't a generic, the PO bought a Bosch as a replacement. To tell the truth, it's just a battery, paying more for it is just paying for a label. Walmart MAXX batteries have served me well and you can afford larger capacity--which will (imho) last longer. BTW, I have a little digital voltage gauge mounted in the left side cigarette lighter spot. Turn on the key to check the battery voltage.