Ok to connect solar trickle charger directly to battery?

If your battery is any good you should just be able to park it, come back in two weeks and restart it without doing anything special. Hopefully you bought a PV panel with an integrated charger instead of just the panel. You're going to lose a lot of power through the window, but maybe it will still be enough since zero should be enough for two weeks. I don't see why you couldn't wire it straight to the battery. Any decent charger will have reverse polarity protection.

If plug in power is an option, there are cheap but good battery tenders available that will do the job with less hassle.

 

Personally, I would buy a "Battery Tender Jr" if the car will be home. If not, I would use one of the Lithium Battery Jump packs since they will hold a charge and be there when you need it. With that said, I have parked for a month in an airport lot and had no problems since the 12v is just for the computer systems, not for the actual starting. Rotating the internal combustion engine is only done with the high voltage battery. The HV battery won't charge from a Battery Tender or a solar panel.

 

all the best!

i just got back from 7 weeks away. will be interesting to see what happens when i try to start mine tomorrow.

 

Most airport park lots I use for long term parking (commercial outfits off the airport grounds) have jumping capabilities. Recall the 12v isn't used for cranking over a motor but rather just starting a computer.

 

Also picking up contactors which is a tougher load due to the inrush.

 

Some of the car solar panels are cheap out there with cheap diodes that can end up draining the battery during the night. I would invest in a good solar controller rather than use straight solar to battery. And I would test the entire system for a few days before leaving it for a few weeks. Monitor battery voltage to make sure it's within safe range. A good solar controller should display battery voltage.

 

VW uses these when the dealers store the cars and they work great. It charges through the OBD port.
OEM Volkswagen VW audi Solar Panel Battery Maintainer Charger OBD2 CS5Q-5D | eBay

 

^ I used to notice all the cars at a nearby VW dealership sporting little solar panels on the dash. Seemed like a good idea. This was 5~10 years back; don't think they're doing it any more though, not sure why.

@vestibule Your best bet, in airport situation, might be to disconnect-and-isolate the battery's negative lead after parking. It's constant low level loads when the car's off that kills the battery; this will effectively avoid that. Be prepared to unlock the car with the manual key, and you will need to crawl through to the back to release the hatch, practice in advance.

You can gamble that 2 weeks is not too much, and that's not a bad bet. OTOH, even if you manage to start up, that 2 weeks of parasitic drain will take a toll.

 

Pin 16 on the OBD II connector is always positive according to the OBD II standard.

 

It was sitting in the trunk of one of the VWs I bought. I guess they forgot to take it back.

 

Charge the battery up and leave it sit.
If it won't last 2 weeks it needs to be replaced.......before it leaves you stranded somewhere.
Honestly.

 

^^^+1
If a 12v battery won't last a month of being parked, its well past needing to be replaced.

 

The sports car 12V has gone an entire "winter" (December-February) without a battery manager installed.

 

If you're going to leave a lithium jump starter pack in your car for 2 weeks. I recommend storing it in an ammo box. In case a cell might explode. Costco carries them.

 

bisco, how did your Prius start up after 7 weeks? Is this the Plugin? What is the longest time anyone ever left their Prius before starting it up without a problem?

I left the fan running in my V for 3+ hours and I was not able to start up my car after that. Had to use a jumper. After that I keep a solar panel and lithium jumper in my car. I can't imagine taking the V out on a road trip and not be prepared. I also keep a usb charger that also shows battery voltage reading so I know I'm in safe range.




The lithium jump starters are very small and very convenient and very easy to use. The only problem is that lithium can be unstable and extra safety is needed to store it in the car.

 

it started fine. was 12.19v when we got home, but after charging it up, it has benn holding at 12.6 for the last 5 days.

the problem with judging by someone else's experience is that you don't know the condition of their battery before they went away. mine was in perfect condition for its age. i monitor it all the time, and have never drained it.

you'r smart to carry the jump pack.

 

btw, don't you have to be in 'ready' to have the fan running?

 

I powered up the car without stepping foot on the brake. This allowed the electronics to function and the engine stayed off. I was hoping that all electronics would function off the HV battery since I just wanted to use the fan. Now I know.