Solar Questions

[paulnptld]

As you can see, I'm 'camping' at the moment and just hooked up a 150 watt portable solar kit.

Here's the question: It has cable ends that are similar to jumpers. I've hooked it up directly to the battery. Is this generally ok?

I'm guessing the battery is draining more quickly than it's recharging anyway because we have our 12V refrigerator running.

[zero]

As you can see, I'm 'camping' at the moment and just hooked up a 150 watt portable solar kit.

Here's the question: It has cable ends that are similar to jumpers. I've hooked it up directly to the battery. Is this generally ok?

I'm guessing the battery is draining more quickly than it's recharging anyway because we have our 12V refrigerator running.

It's not good for the battery long term but won't hurt it for short usage. 150 watts of panel will barely make 7-8 amps @ 14 volts in noon sun. Not enough power to hurt a large battery unless hooked long-term. Generally speaking any panel over 20 watts and hooked full-time to a battery ought to have a controller. I assume your panels have built-in blocking diodes? If not and with no controller- they will drain the batteries when the sun is blocked. Most new panels have them.

[MontanaChinook]

I have a portable panel with different connectors. One of the sets of connectors are the jumper style cables. So yeah, they're fine. Mine has a built on charge controller. I'm guessing yours does, too?

From what I hear, the 12V fridge draws a very large amount of power (so large that most people don't even use it on 12V while they're driving). I'm guessing it'll drain your battery pretty quick. Do you not have a propane option? I've been keeping mine on propane 100% of the time, unless it's so windy while I'm driving that it keeps blowing out.

I don't have a microwave, tv, or ac. I haven't even had to use my solar panel, even after sitting for 5 days...Guess I kind of spent unnecessary money on that.

[zero]

From what I hear, the 12V fridge draws a very large amount of power (so large that most people don't even use it on 12V while they're driving). I'm guessing it'll drain your battery pretty quick. Do you not have a propane option? I've been keeping mine on propane 100% of the time, unless it's so windy while I'm driving that it keeps blowing out.

An absorption refrigerator draws 7-10 amps @ 13 volts when the thermostat calls for cold. A 12 volt compressor-type refrigerator draws 5-6 amps @ 13 volts when the compressor is running. The latter tends to run less and draw less average amps per hour. Either one can be used with no problem when driving. That assuming the Toyota has the 60 amp alternator. Some older ones like a 78 Chinook only have a 45 amp alternator. Maybe if someone has a small alternator and a lot of lights on - and a stereo drawing high amps - they might have some problems when the engine is idling. Otherwise - I don't see the problem. I've done a lot of night driving with an absorption refrigerator and never had any real issue. Only time I came close was a big Class A that only had a 45 amp alternator. I was driving at night with all the lights on, and the engine-driven AC on (electric clutch) and the 3-way refrigerator in 12 VDC mode - and then my charge light would start to glow a bit when sitting at a long red light.

Long story short - a truck without the lights on draws around 7-10 amps unless the air conditioning is on. The 60 amp alternator puts out 25 amps at engine idle and a lot more as soon as the engine is running a little faster. Running a frig usually won't be an issue. Run with headllights, and AC on and with a small alternator - and then yes, it can be a problem.

[paulnptld]

The refrigerator ran fine for two days with just a single battery and the solar panels hooked up. It's an older 12v Norcold. My next project is to either a) better insulate the Norcold or buy this small Kenmore energy star model: http://www.sears.com/kenmore-3.1-cu-ft-2-door-compact-refrigerator/p-04695693000P?prdNo=5

[MontanaChinook]

Great. I insulated my new Dometic when I put it in. I think that as important as insulating the fridge is making sure the cooling fins on the back are well ventilated. I insulated the heck out of mine, but that's only half the battle. Insulating it will help keep it cold once it's cold, but won't help with the actual cooling. I know some people install little computer fans to blow on the back of the fridge to help the cooling unit stay cool.

I didn't help my cause when I painted the fridge vent on the side of my camper black...wasn't really thinking about what the vent was for, was just thinking the all white exterior of my camper needed some contrast.

That's good to know that you aren't drawing that much power.

Can't decide if that will help me...I know mine runs the most efficiently on propane, but since I'm in the southwest with plenty of sun, it might make sense when I'm camped for a bit to run it on 12V, and actually make use of that solar panel I bought! I've been basically living out of my camper for the last two months, and I've had to fill my 20lb propane tank three times, each time cost less than $10. That's with the fridge running constantly, cooking on the stovetop, and occasional (until the heat really hit) furnace use, just a couple cycles on the coldest mornings to get an initial blast of heat for comfort.

Weird thing about my fridge (weird to me who doesn't really know much about this stuff, anyways) is that there is no adjustable thermostat for the 12V setting on my fridge. Propane and AC I can set a thermostat, but for 12V, it's just "on". I might have to experiment on a hot day with 12V and see if it does the job.

It was 100 in Tucson yesterday...yuck.