My wife and I have been stricken twice now with dead car batteries after leaving our cars parked for a week or more during vacations.
The last time it required calling a AAA to give us a jump as we parked at a hotel and they didn't have a jumper box.
I'd like to keep this from happening again. It's Phoenix, so sun is plentiful (as is interior heat). I want a jump start (or battery tender) option that won't lose juice after a few days, won't explode, and is fairly reliable.
I had a lithium jump pack stashed in my camper just in case. Finally had a reason to use it this weekend - battery was swollen and toast. So I can't recommend those.
What about just bringing a wrench and disconnecting the battery? Or check for dark current, as a week shouldn't take out a battery.
How about using a battery disconnect switch?
Keith Tanner said:battery was swollen and toast.
Lithium does not like heat at all.
How about a solar trickle charger?
https://www.harborfreight.com/15-watt-solar-battery-charger-68692.html
You can find larger capacity ones, same plug in concept, at RV stores.
NFI or personal experience with this, but I have thought about one for the camper.
mike h
red_stapler said:Keith Tanner said:battery was swollen and toast.
Lithium does not like heat at all.
Then it's a bad idea to leave one in your car in the PHX long term parking lot!
Mine wasn't exposed to any extreme heat, but I didn't keep it in the fridge either. If you can't keep it in the car, then it's pretty useless as a jump pack.
I have solar trickle chargers on 2 vehicles. The RN Truck has an old HF one on the dash. My batteries seem to last longer since I put it in years ago. The RAV has a Mil Spec one, same as used on the Abrams. Oh, the Army put them on the Abrams tanks because, you know, tanks sit around in the parking lot all the time except for the rare events when you take them out to go kill someone or practice killing someone. Batteries go dead with them just sitting there. So they started putting these solar trickle chargers on them and their battery replacement costs dropped to nothing.
These solar trickle charger - are they wired to the battery or through the cigarette lighter?
Do military vehicles have cigarette lighters?
I have the solar on my camper set up to also charge the starter battery. The battery that's in there is a tired Optima that was dying with extended parking. Now it's topped up permanently. It's not quite a little dashboard panel with a 100W panel on the roof and a fair bit of electronic switching going on, but the concept works for sure.
I have the RAV one wired directly to the battery. The Truck one goes to a cigarette lighter socket that I wired to an always on circuit. In Toyotas, the lighter is switched with the key.
I made some solar chargers out of some surplus panels a friend had and they're awesome. I love love love the ability to park a car for as long as I like and have the battery be as fresh as can be when I get in.
If the cigarette plug is live with the key off you can plug in there. Works great. If not you'll either need to rewire it, add one that's on all the time, or use alligator clips to some always on wires or to the battery. Usually you can close the door on the wire and sneak it under the trailing edge of the hood and hook it up then close the hood without damaging anything.
I have used solar chargers in the past.. they work great
at least as long as you do not get a cloudy week or two
I go on week long trips in Minneapolis. Boy she cranks slow after a week in -10
Fueled by Caffeine said:I go on week long trips in Minneapolis. Boy she cranks slow after a week in -10
I had that once--not mn, but a battery already on its way out sat for 5 days. Tried to start it in -18. Lights came on very dim, couldn't get it to crank. Had to dump the clutch to get it to start after running down a hill. Still didn't want to start.
Seriously, you guys need to look at your dark current loads if you're having that much trouble after such a short inactive period. And don't tell me I don't know cold!
Keith Tanner said:Seriously, you guys need to look at your dark current loads if you're having that much trouble after such a short inactive period. And don't tell me I don't know cold!
On mine, it was a battery that already needed to be replaced. 14 years old!!!
But yeah, in this case something is definitely off.
Dark current sounds so sinister. Parasitic draw just sounds gross, like worms are eating your stray electrons. Dark current suggests Voldemort is nearby. I like it.
To the OP: solar panel works great. Voldemort hates the light.
In reply to Keith Tanner :
I've never had a starting failure even in the coldest weather, but It sure does crank slow.
And modern cars have lots of dark current from the factory.
Yeah, IIRC many modern cars basically say “expect a dead battery if you leave for a few weeks.”
It's not a direct answer to your question, but if I self-park at the airport I pretty much always disconnect the battery. But then, all our cars have trunk mounted batteries, so it's easy to do when pulling out the bags. BLOWS though when I've had to reconnect standing in pouring rain.
Anyone have a recommendation on solar trickle chargers? Most of the cheap imports don't seem to have over charge protection.
Battery Tender has some options with "built-in charge controller to prevent overcharging," they're kind of proud of.
Battery Tender also has a stand-alone solar charge controller you can add your own solar panel to.
With that stand-alone Battery Tender and something like this skinny 10 W Polycrystalline panel, you could come up with a 10 W solar charger about $30 cheaper than the ready made one from Battery Tender. I'm sure most of you are like me and have your own Professor Farnsworth-esque drawer of assorted lengths of wire. Hard wiring would be simple, or cannibalizing something I have laying around with a 12V cigarette liter plug or alligator clips on it would be simple enough.
VWs and Audis a few years ago would get a solar charger from the factory during transit to the dealer. The dealer would take it out before selling the car. There are two versions, one that plugs into the lighter and the other one will plug into the OBD2 plug. Some cars have the lighter switched so it won't work plugged in there. OBD2 connector has B+ all of the time.
There are dealers who will sell you one of these used if you look. Ebay can be your friend. This one's $16.50
Ooo, plugging into the OBD-II port is a good idea. I like that solution.
OBD-II Plugs should all be the same so should it work in a car that isn't a VW? I suppose combining VW bits in a Fiat is probably asking for trouble though.
You'll need to log in to post.
