?'s about a 12 v. ice chest

[dudevato]

.......The chest itself is large enough to put in 4 six packs of beer. It's missing its lid.  The cover to the electrics of it say "input: 12 volts @ 5 amps"  The fins outside get warm and the fins inside get cool. Each set of fins is approx. 3"x5" There is one small motor with a long armature that has a small squirecage type fan on each end, blowing on each set of fins.  It wouldn't stay spinning when I first connectecd it to my car battery, engine off, but after some spray WD-40 is does. Maybe a bit slow, but if it was spinning twice as fast I can't imagine any heat or cold being moved off the fins. I'll give this cooler a full checkout before I spend any money: wired to the battery with the car running and checking temps after 30 minutes.

Finally my question,(if this thing checks out):

   Can you tell me what size solar panel I'd need to run this. The cooler would be wired with what ever size wire is needed to make it effectient and maybe 30 feet from the panel.  I'm thinking I'd like a panel that puts out 17 volts, that seems to be a common amount and I'd also like to be able to run a portable radio (uses 8 size D batteries) The radio plays well from a 5 watt panel, but needs a 10 watt-er to be able to play CD's. This will be a little hobby project and I'm thinking if I put all the mechanics in a smaller cooler, with 6" of rigid foam insulation I could keep a 6 pack real cool in the shade, on the patio. I'm thinking the more 'fan' blowing on these fins the better. I could find a couple of 3 or 4" fans like computers use and run them off the panel also. So again, what size panel would make this all happen for me.  And figure in some 'lee-way' cause I don't want cool beer, I want Cold beer. I'm not interested in any battery backup.  Could all this happen for $100? Thanks for your time and knowledge.

[Countryboy]

12 volts at 5 amps is 60 watts.

If you have 24 hours a day of sun where you live, you can get away with a 60 watt solar panel.  Unfortunately, most places only get about 5 good hours of sunlight.  60 watts an hour consumption, for 24 hours is 1440 watts.  You would need 288 watts of solar, for 5 hours a day, just to break even on power.  This also means you would need a battery to store extra power you get for the 5 hours, so you can run the fridge 24 hours a day.

If you don't want any battery backup, then plan on the fridge NOT getting cold until you have sunlight.  It may take a couple hours of running before you get COLD beer.  And, you will only have cold beer for a couple of hours.  If you want cold beer at all hours, then you will have to have a battery.

If you just run the fridge when the sun is shining, you are going to need 60 watts of solar.  Considering that solar panels are running between $4-$5 a watt, a 60 watt panel is going to cost you $240-$300.

For what you want, it is unrealistic to do it for $100.

[Volvo farmer]

Countryboy hit the nail on the head for your solar requirements.

I haven't used many of these peltier devices but I've read a bit about them. Cold beer to my taste, is in the 33F-36F range. Sorry I don't have references but I've read somewhere that these types of coolers can maintain something like 40F on a warm day, now you're into the range of cool beer, not cold.

Additionaly, if you had to spray WD40 on the fan bearings to make them go, they are shot. If you're persistant, you could continue to spray lubricant in there every few days and keep them working but in the long run, you need to fix that.

[coldspot]

I've got a couple of smaller TEC coolers

They only hold about 9 cans each.

Because they are coolers, they do stay cold if not

out in the sun getting cooked, (lids closed shady place).

They only have fans on the outside, to cool the hot side of the TEC. Or Vis-a-versa if switched to warmer mode.

I figured they are about 80 watt units, TEC's are power hungry and need lots of juice.

I've put a few 180 watt+ units in computers for cooling and used an extra power supply just for them!

No, I don't think you can do what you want for that price range.

But, with a storage bat and a wind/solar combo???

Yea much more money, but it's only money well spent!

[nothing to lose]

As others have said.

I have had 2 or more of those power hungry Ice chests. One perfectly good sitting in the yard right now, same place for over a year now

They are ok if used right, by right I mean NOT as intended!

They do not get cold fast at all normally. Put cold meat in one at ambeint temps at the store and meat warms up before the cooler gets cold. Run the cooler on the way to the store so it's cool before you put in the meat and it works ok.

Manual says do not use ice in it, if you want something cold you use the ice anyway!!

 IF you leave it plugged into the car for awhile with engine not running, forget starting the car later!

More similar reasons you may have found it somewhere, maybe it was one of mine before I Knew what a peltier was. Hopefully the newer ones work better but I dought it.

That Peltier, cooling heating device, is a nice toy and expensive to buy. Save it even if you don't use it for beer anyway.

Since you have it, play with it. Heat one side HOT and cool the other, makes a little power, or should.

As already said, 12V at 5amps is 60watts. Alot of money for a solar pannel to run it for no more that it does.

If sun comes up good around 7Am I would not expect the beer to be cold untill 12Noon. Even then the best will probably only be cool beer, not actaully cold. When the sun goes down and the pannel stops making power, you have an ice chest without ice full of beer which is slowly getting warmer.

For the money and effert to have cold beer using that unit you might be better off making ice at home in the freezer and filling a $5 ice chest with it.

All is not lost though, you could make a nice 4-6 can cooler to plug into the car while driving and have a cold/cool Coke or Pepsi instead.

[Opera House]

I have a 12V 4A fridge with a compressor at my camp.  It should only run about one quarter of the time.  I bought two new 75W panels and a 100AH battery.  It would run for about 2-3 days before the battery died.  Sometimes 5 hours of sun is very optomistic.  Your dream of cheap cold beer is not realistic.

[elvin1949]

 Got one of those.It get's 40 deg. below the

outside air temp.

 120 deg.outside 80 deg. beer NOT COOL.Work's good in cool weather.If ambient temp is 80 deg. or less

work's ok.

 Uses to much power.

later

elvin

[The Crazy Noob]

I know from expirience that those electric ones are very poorly insulated. Just put a lot of insulation around it and it should stay cold to cool for a few days if left unopened.

[richhagen]

Hmm, It would cost quite a bit to run that chip continuously by solar.  The Peltier device sounds like it is insufficient for the task it is used for.  If one reduces the surface area of the cooler, and increases the insulation, the heat transfer by conduction and radiation could probably be reduced dramatically.   It seems like one would be better off to make a one or two can cooler with it, using an ultra insulated box.  Open it from the top like a deep freeze to minimize the convective losses when opening, and add a thermistor controlled circuit to turn off the power to the Peltier device when it is cold enough inside.  Maximize the surface area of the heatsinks on both sides, perhaps making a thick aluminum box to line the inside of the cooler, and a huge heatsink on the outside to negate the benefit of a fan.  It would cool more rapidly and hopefully would not run all the time.  still one would need a battery, a way to charge it, and a low voltage disconnect to protect the battery from damage.  I do not know what one could realistically reduce the percentage of runtime of the Peltier chip to, but I would guess that you would still need a sizable battery and relatively costly generating capacity.   Rich Hagen