Hi all ok so was thinking today on how long it would take (1) solaris 26 giving me 26 watts of power or (2) solaris 26 solar panels linked together giving me 52watts of power to charge a dead car battery?   they come with alligator clips.

If i had to guess? In perfect conditions i'd say a day+, assuming the Battery is completely dead.

Well that's about 4.3 amps in perfect conditions, so you'll be GTG in 2 weeks.

these are the specs for (1) solaris 26.........also read on another site said 1600 milliamps

Wattage:
26 W
Output:
12 V
Power:
1.4Amps MAX
Weight:
1.7 lbs
Open Size:
21 3/8 x 42 in (cm)
Closed size:
8 ½ x 11 in (cm

52 Watts at 13.8V (minimum charge voltage, usually 14+) is roughly 3.77 amps in full sun. Some of the biggest car batteries have a rated capacity of 100Ah. At that rate, it would take 26.5 hours of full sun time to recharge that battery. I've seen smaller ones that only have 55Ah so that would be ~14hours of full sun. Sometimes car batteries are down enough that they won't turn over the vehicle but their voltage hasn't dropped completely to zero (very bad, btw). So, you're battery may be down to 40% capacity remaining but it can't deliver enough current to turn over the motor.

Recharging a dead car battery requires a pretty beefy power source. Even the 200W folding solar panel I have would take a long time and might not get done in one full day from dawn to dusk. Having a jump battery is probably the way to go and use the solar to keep the jump battery maintained at full charge. I got a 35-ish amp hour battery from Harbor Freight in their solar power section for about 60 bux. I use it to power my ham radio and have a gizmo that uses the cig lighter socket to maintain charge when the motor is on. I've had to use it to jump my wife's car a couple of times when she wasn't driving it enough.

Panel output watts /12  = panel amps.

Amp hour storage of battery / panel amps = number of hours at 100% panel output = theoretical full charge time, ignoring cable resistance, sun movement, etc.

so you guys are saying if I linked both my solaris 26 solar panels together it would take about 24hrs of full charge time........sorry guys and I know a couple of you are only trying to help so don't read this as me being rude, but I suck at math and on top of it your equations make no sense to me what so ever lol its all greek to me.

just need to know if both are linked together roughly a day or so full charge time......and if I use only one solar panel(26 watts) safe to assume 2/3 days?

It depends...

Full sun?  Keeping the panels turned towards the sun?  Cloudy day?  How low is the battery really?  Winter or summer?  What is the temperature outside?

All of those and more can increase or decrease your time needed.  If no parasitic loss from a bad battery or some issue with the vehicle (if you leave it connected while charging) I think you could get the vehicle to start in a day or less with both panels, assuming the battery is just below capacity for starting and the car isn't going to need to turn over for a long time before it hits.  An alternator is a much better charger than solar panels, hence why I think in "how long until I can start the engine?" than time to fill a battery to capacity.

I know, that doesn't help...

no it does......thank you

In my experience as a rule of thumb, real world portable solar panel output tends to be about half what is claimed under ideal conditions.

Here's a little graphic to help ya with the math.
If you know two of the variables the third is easy to find.
Cover the unknown and the math becomes obvious.
Good luck..

I'll take 'what are the panels' open voltages in direct sun?' for $500, Alex.

What ever you do, get a digital charge controller like my Morningstar SS-10-L.

Chris

Peak power doesn’t come at 12v, it is about 17. OP needs a charge controller, I like the 50w one that DIYSOLAR4U sells.

A battery DOES NOT have to be at 100% charge to start a vehicle.
So, how much do you need to start it, where is the battery currently at and how fast will the panels get you there.
Oh, manual transmissions which can be bump started require very little power to energize the alternator which will almost immediately bring up enough voltage to keep an engine running and charge the battery further.

I have stopped a few times in the last few months to assist people on the side of the road.    Most of them have been flat tires, one was a dead battery/non-operating alternator.   On the flat tires, two for them didn’t have a jack to change the tire.   One of them had a spare tire that was also flat.   On that one we couldn’t air up the spare because the valve stem of the spare didn’t have a cap and it was packed full of dirt.   One of them was an Army vet that didn’t have a jack and it was -4 F outside.   He was nearly giddy that I stopped to help.   He figured that he was going to be stuck for hours.   One of them they had the tire off but couldn’t get the spare on.   It was interesting in that it was a full sized spare and it had really deep holes for the lug nuts.   I had to lay on the ground to line up the holes with the studs.

If you are prepared with a spare tire, jack, proper lug wrench, jumper cables and jump-start pack then you are miles ahead of most people.

Things that I carry and am thankful that I do:

Flash lights/Head lamps
Phone Charger
12 Volt Air Compressor
Tire guage
Spare fuses
15000 lb tow strap
Shackles and short chain for the tow strap
Small First aid kit
Small Collapsible Snow shovel
Military issue E-Tool
Work Gloves
Rain gear
Cold weather gear, including 0 Deg F boots
Poncho liner
Poncho
Mosquito repellent
Knee pads
Zippo Style hand warmer with extra bottle of fluid
Full Change of clothes
Topo and County maps of the state
GPS
Small Cooler with some water (keeps it cool in the summer and unfrozen in the winter)

I have used everything on this list on more than one occasision.

Hopefully that helps.

2Hut8

Edit:  I have no idea how this post end up on this thread.......    I wrote it for a thread involving a guy wanting to outfit two vehicles for SHTF.   I knew that I wrote the post but never figured out where it went.

Solar panels are rated for a very specific condition, full direct sun. Meaning the panel is pointed directly at the sun. In reality that will never happen. On a sunny summer day with stationary panels you can figure the equivalent of 5 hours of "full sun". Moving the panels to face the sun every 30 min. or so will give you a bit more.

So a 1.5A output will give you about 7-9 amp hours of power on a sunny day. A typical small car battery, discharged to 50% capacity, would charge in about 3 days. Even then it wouldn't be a full charge.