Camping Camper

Question

[This is x-posted to all the newsgroups I could think of with the knowledge base and possible interest in the topic. If you are uncomfortable, trim the headers, as I read all these groups for info.] Today, while cruising through Sears, I saw one Igloo Kool-Mate sitting on the shelf. (I was getting a couple of lightweight rod and reel combos, Zebco 202s, for a Crappie trip next weekend with the [commonlaw] wife.) Anyway, I got it on sale for about $50.00 and took it to the car. Plugged it in, and drove 40 miles total running it empty. It had cooled completely by the time we got home. I must say I was pleased. But ever looking for as much efficiency as possible, I have some questions. I got the thing for a remote cabin we have for weekend getaways. (I grew up on a dirt farm in ‘Bama, so Atlanta gets me batty!) Anyway, we are going solar out there, and refridgeration was a concern. After looking at all the hi-efficiency fridges, and gas models, I figured this would be a real good compromise. Now, we only store drinks, and a stick of butter we bring with us, and maybe some cheese or steaks or such, for the weekend. We keep the reefer we have now off during the week, empty, since we aren’t there. Now, I was figuring I could hot glue styrofoam sheets to the outside of the cooler, excepting the area where the vents, fan and power cord are, of course. The only problem with it I can find is that it is a continuous use heat pump, with no auto shut off. According to the spec but it could be better. Now, I have a few other ideas to bounce, let me know what ya’ll think. Adding a digital thermometer to the inside, with the readout on the door. Anyone know if I can wire the thermometer to a relay, so that it will shut on and off automatically when the temp. reaches a cutoff and cut-on point? I figure the mods aren’t that difficult to make, especially if the thermometer has an alarm for a high and low temp. Run the alarm wires to a relay switching power to the reefer on and off. All around, how’s it sound? And has anyone played with these before? — “Government is not reason. Government is not eloquence. It is force. And, like fire, it is a dangerous servant and a fearful master.” —George Washington “In matters of conscience, the law of majority has no place.” -Mohandas Gandhi “If you will not fight for right when you can easily win without bloodshed; if you will not fight when your victory will be sure and not too costly; you may come to the moment when you will have to fight with all odds against you and only a precarious chance of survival. There may be even a worse fate. You may have to fight when there is no hope of victory, because it is better to perish than to live as slaves.” — Winston Churchill on the eve of Britain’s entry into World War II

Response

[This is x-posted to all the newsgroups I could think of with the knowledge base and possible interest in the topic. If you are uncomfortable, trim the headers, as I read all these groups for info.] Today, while cruising through Sears, I saw one Igloo Kool-Mate sitting on the shelf. (I was getting a couple of lightweight rod and reel combos, Zebco 202s, for a Crappie trip next weekend with the [commonlaw] wife.) Anyway, I got it on sale for about $50.00 and took it to the car. Plugged it in, and drove 40 miles total running it empty. It had cooled completely by the time we got home. I must say I was pleased. But ever looking for as much efficiency as possible, I have some questions. I got the thing for a remote cabin we have for weekend getaways. (I grew up on a dirt farm in ‘Bama, so Atlanta gets me batty!) Anyway, we are going solar out there, and refridgeration was a concern. After looking at all the hi-efficiency fridges, and gas models, I figured this would be a real good compromise. Now, we only store drinks, and a stick of butter we bring with us, and maybe some cheese or steaks or such, for the weekend. We keep the reefer we have now off during the week, empty, since we aren’t there. Now, I was figuring I could hot glue styrofoam sheets to the outside of the cooler, excepting the area where the vents, fan and power cord are, of course. The only problem with it I can find is that it is a continuous use heat pump, with no auto shut off. According to the spec but it could be better. Now, I have a few other ideas to bounce, let me know what ya’ll think. Adding a digital thermometer to the inside, with the readout on the door. Anyone know if I can wire the thermometer to a relay, so that it will shut on and off automatically when the temp. reaches a cutoff and cut-on point? I figure the mods aren’t that difficult to make, especially if the thermometer has an alarm for a high and low temp. Run the alarm wires to a relay switching power to the reefer on and off. All around, how’s it sound? And has anyone played with these before?

Yes of course, I purchased mine with the automatic temperature control built in, several companies supply them that way and also as food warmers. Which only requires reversing the polarity to the thermoelectric module. If you real want to be efficient do not glue anything to it. Instead build a air tight insulation box to place it in, with a two hinged doors. One to get food and the other to allow air flow when you are operating it (absolutely necessary or it will over heat and be destroyed. When it is cold enough turn it off and close the door it will stay cold for a day if you don’t open it. Never palace warm food in it if possible. It takes more than a day to completely cool a full cooler with warm food. If you don’t shut of the air flow it will warn up the external heat sink then the thermoelectric module and then the heat sink inside and eventually the contents. These coolers are designed to keep things cold and have limited cooling power only about 50 degrees below the outside air cooling the heat sink. You can get them to freeze the contents if it is cool enough at night or place ice or snow near the air cooling it.

Response

Wow Frank, you bought one today too? I was going to tell everyone of this cool little 12VDC cooler, and you beat me to it. Oh well, I haven’t used it yet, but I think it will come in very handy on road trips, camping, and Y2K (if needed). I’m in the process of getting everything I need for power outages to run off 12VDC. Now that I have this cooler, I can load most of what I need from the frig into it when I decide to stop powering the frig using the gasoline generator. Great write up on it, saves me some time talking about it. I’m going to look into a thermometer like you are. DC [This is x-posted to all the newsgroups I could think of with the knowledge base and possible interest in the topic. If you are uncomfortable, trim the headers, as I read all these groups for info.] Today, while cruising through Sears, I saw one Igloo Kool-Mate sitting on the shelf. (I was getting a couple of lightweight rod and reel combos, Zebco 202s, for a Crappie trip next weekend with the [commonlaw] wife.) Anyway, I got it on sale for about $50.00 and took it to the car. Plugged it in, and drove 40 miles total running it empty. It had cooled completely by the time we got home. I must say I was pleased. But ever looking for as much efficiency as possible, I have some questions. I got the thing for a remote cabin we have for weekend getaways. (I grew up on a dirt farm in ‘Bama, so Atlanta gets me batty!) Anyway, we are going solar out there, and refridgeration was a concern. After looking at all the hi-efficiency fridges, and gas models, I figured this would be a real good compromise. Now, we only store drinks, and a stick of butter we bring with us, and maybe some cheese or steaks or such, for the weekend. We keep the reefer we have now off during the week, empty, since we aren’t there. Now, I was figuring I could hot glue styrofoam sheets to the outside of the cooler, excepting the area where the vents, fan and power cord are, of course. The only problem with it I can find is that it is a continuous use heat pump, with no auto shut off. According to the spec but it could be better. Now, I have a few other ideas to bounce, let me know what ya’ll think. Adding a digital thermometer to the inside, with the readout on the door. Anyone know if I can wire the thermometer to a relay, so that it will shut on and off automatically when the temp. reaches a cutoff and cut-on point? I figure the mods aren’t that difficult to make, especially if the thermometer has an alarm for a high and low temp. Run the alarm wires to a relay switching power to the reefer on and off. All around, how’s it sound? And has anyone played with these before? — “Government is not reason. Government is not eloquence. It is force. And, like fire, it is a dangerous servant and a fearful master.” —George Washington “In matters of conscience, the law of majority has no place.” -Mohandas Gandhi “If you will not fight for right when you can easily win without bloodshed; if you will not fight when your victory will be sure and not too costly; you may come to the moment when you will have to fight with all odds against you and only a precarious chance of survival. There may be even a worse fate. You may have to fight when there is no hope of victory, because it is better to perish than to live as slaves.” — Winston Churchill on the eve of Britain’s entry into World War II

Response

Ok, I was sitting here about five hours after my last post when it hit me Why not just have a temperature actuated relay, or some other temperature controlling on/off circuitry. Did a websearch and found this page Dwyer’s Instruments Inc. their recommendation for switching a 12Vdc/5Amp ckt off at <40F and on at 45F. I will post back with their response when I get it. — “Government is not reason. Government is not eloquence. It is force. And, like fire, it is a dangerous servant and a fearful master.” —George Washington “In matters of conscience, the law of majority has no place.” -Mohandas Gandhi “If you will not fight for right when you can easily win without bloodshed; if you will not fight when your victory will be sure and not too costly; you may come to the moment when you will have to fight with all odds against you and only a precarious chance of survival. There may be even a worse fate. You may have to fight when there is no hope of victory, because it is better to perish than to live as slaves.” — Winston Churchill on the eve of Britain’s entry into World War II

Response

[This is x-posted to all the newsgroups I could think of with the knowledge base and possible interest in the topic. If you are uncomfortable, trim the headers, as I read all these groups for info.] Today, while cruising through Sears, I saw one Igloo Kool-Mate sitting on the shelf. (I was getting a couple of lightweight rod and reel combos, Zebco 202s, for a Crappie trip next weekend with the [commonlaw] wife.) Anyway, I got it on sale for about $50.00 and took it to the car. Plugged it in, and drove 40 miles total running it empty. It had cooled completely by the time we got home. I must say I was pleased. But ever looking for as much efficiency as possible, I have some questions. I got the thing for a remote cabin we have for weekend getaways. (I grew up on a dirt farm in ‘Bama, so Atlanta gets me batty!) Anyway, we are going solar out there, and refridgeration was a concern. After looking at all the hi-efficiency fridges, and gas models, I figured this would be a real good compromise. Now, we only store drinks, and a stick of butter we bring with us, and maybe some cheese or steaks or such, for the weekend. We keep the reefer we have now off during the week, empty, since we aren’t there. Now, I was figuring I could hot glue styrofoam sheets to the outside of the cooler, excepting the area where the vents, fan and power cord are, of course. The only problem with it I can find is that it is a continuous use heat pump, with no auto shut off. According to the spec but it could be better.

1== 4.5 amps at 12 volts is 4.5 * 12 = 54 watts, which is a fairly heavy drain. Those contemplating a similar small fridge might want one that operates off propane gas instead….not that propane will always be available either. Now, I have a few other ideas to bounce, let me know what ya’ll think. Adding a digital thermometer to the inside, with the readout on the door.

2== Sure, this is easy. A few months ago I picked up one made in China for a local firm. Liquid crystal display, switchable indoor/outdoor [comes with 3 meters of cord and external probe], switchable centigrade/ fahrenheit. Range plus or minus 50 C, which is minus 58 F to plus 122 F. Display is about 12 mm [ 1/2 inch] high. Constantly on, as circuit uses so little power that get the life of the battery out of it anyway. Say about two years if don’t keep pressing the backlight display button to light up the display. From memory, was about $A 12 which would be about US$ 7.80. Check your local Radio Shack or other electronics store. Anyone know if I can wire the thermometer to a relay, so that it will shut on and off automatically when the temp. reaches a cutoff and cut-on point? I figure the mods aren’t that difficult to make, especially if the thermometer has an alarm for a high and low temp. Run the alarm wires to a relay switching power to the reefer on and off.

3== Have seen similar units to the one I’ve described which to have a settable alarm for high or low temperature, might be slightly more expensive, but not much. 4== Setting up an “automatic” controller is a bit more of a problem. For one thing, if you use a relay to switch the current, the relay coil itself consumes power. There are ways to get around the use of a relay using solid state switching, but the next problem is providing a “dead band”. 5== To explain this, assume you devise a circuit that switches the unit on when the temperature rises to 34 deg F. Fine, easy enough to have a control unit do that. Problem is, though, that the unit starts operating at 34 F. A few seconds later, the temp drops just below 34 F., so it shuts off….so it is continually switching off and on around that 34 deg set point, which not only wastes power, but could eventually cause problems. In a room thermostat, if had something like this the furnace [or whatever] would be continually cycling. So a conventional thermostat set at say, 68 F, actually doesn’t turn on until the temperature drops to perhaps 64 F and doesn’t shut off until it rises to, say, 72 F. So with your fridge, would want something that perhaps switches on at 36 and off at 32. 6== Possibly the easiest way to accomplish this is to salvage an old thermostat off a junked refridgerator and use that in conjunction with a relay of some sort. [ The contacts on the old fridge relay may switch an amp or two at 120 volt AC, but that doesn't mean they will handle 4.5 amps at 12 V DC very long without burning out. 7== The easiest solution, of course, is to find a way to get by without refridgeration. ~ larryn All around, how's it sound? And has anyone played with these before? Yes of course, I purchased mine with the automatic temperature control built in, several companies supply them that way and also as food warmers. Which only requires reversing the polarity to the thermoelectric module. If you real want to be efficient do not glue anything to it. Instead build a air tight insulation box to place it in, with a two hinged doors. One to get food and the other to allow air flow when you are operating it (absolutely necessary or it will over heat and be destroyed. When it is cold enough turn it off and close the door it will stay cold for a day if you don't open it. Never palace warm food in it if possible. It takes more than a day to completely cool a full cooler with warm food. If you don't shut of the air flow it will warn up the external heat sink then the thermoelectric module and then the heat sink inside and eventually the contents. These coolers are designed to keep things cold and have limited cooling power only about 50 degrees below the outside air cooling the heat sink. You can get them to freeze the contents if it is cool enough at night or place ice or snow near the air cooling it.

Response

And has anyone played with these before? Yes of course, I purchased mine with the automatic temperature control built in, several companies supply them that way and also as food warmers. Which only requires reversing the polarity to the thermoelectric module.

I have had several such units. What gives out are the fans. Unless you get the trucker model with a high-reliability fan, the fan will fail in a couple of months and you will need to get yourself ball bearing fan like from Radio Shack and modify the baffle to take it. We had a model from Germany and I spent a lot of time looking for the right model. One day the fan failed suddenly and the unit 'burned up', i.e. the junctions disconnected. They cost about $30 each, if you can find them, so that means getting another unit. Were I you, I'd go in for a small gas refridgerator from an old travel trailer.

Response

And has anyone played with these before? Yes of course, I purchased mine with the automatic temperature control built in, several companies supply them that way and also as food warmers. Which only requires reversing the polarity to the thermoelectric module.

Is this DC cooler based on the Peltier effect? If so, they are convenient because they are almost solid state (minus the fan) but they are supposedly inefficient as all hell... You can see a good description of how simply they work at... http//www.americool.com/basics.htm and then http//www.americool.com/moduleworking.htm And you can see why simple polarity switching changes the cooler to a heater... thus it is often used for laboratory devices that have to keep something at temp X with only 1 degree variance, -- Nat Kimble

Response

And has anyone played with these before? Yes of course, I purchased mine with the automatic temperature control built in, several companies supply them that way and also as food warmers. Which only requires reversing the polarity to the thermoelectric module. I have had several such units. What gives out are the fans. Unless you get the trucker model with a high-reliability fan, the fan will fail in a couple of months and you will need to get yourself ball bearing fan like from Radio Shack and modify the baffle to take it. We had a model from Germany and I spent a lot of time looking for the right model. One day the fan failed suddenly and the unit 'burned up', i.e. the junctions disconnected. They cost about $30 each, if you can find them, so that means getting another unit. Were I you, I'd go in for a small gas refridgerator from an old travel trailer.

Igloo sells all the parts for the cooler, including the PC board and Peltier unit. Am thinking about buying replacements for the peltier and the fan and the board, just to keep onhand. -- "Government is not reason. Government is not eloquence. It is force. And, like fire, it is a dangerous servant and a fearful master." ---George Washington "In matters of conscience, the law of majority has no place." -Mohandas Gandhi "If you will not fight for right when you can easily win without bloodshed; if you will not fight when your victory will be sure and not too costly; you may come to the moment when you will have to fight with all odds against you and only a precarious chance of survival. There may be even a worse fate. You may have to fight when there is no hope of victory, because it is better to perish than to live as slaves." -- Winston Churchill on the eve of Britain's entry into World War II

Response

We have an Igloo like that. The plug to the Igloo melted, as did the wiring within 10 hours of use. I contacted Igloo, and they were very rude, and refused to do anything, even though it was still in warrenty. From what I understand, that is their 'normal' way of doing business. We'll not buy anything made by Igloo again. Dusty

Response

We have an Igloo like that. The plug to the Igloo melted, as did the wiring within 10 hours of use. I contacted Igloo, and they were very rude, and refused to do anything, even though it was still in warrenty. From what I understand, that is their 'normal' way of doing business. We'll not buy anything made by Igloo again. Dusty

Your fan probably shorted out. Once that happens, it is all over. The models sold in truck stops have long-life fans, and you pay a little extra for that. Otherwise, about 10 hours on a fan motor is not unhead of. I have had some fail in that length of time. If they do fail, and you don't pull the plug, everything does start to melt. I have had that happen with a Gemman model I really liked, but I spent a lot of time looking for fan motors too. One failed while I was at work and the leads to the junctions melted and that was the end of that cooler.

Response

Your fan probably shorted out. Once that happens, it is a lot of time looking for fan motors too. One failed while I was at work and the leads to the junctions melted and that was the end of that cooler.

put a thermal fuse in series with the power supply. clip the fuse to the heat sink. If heat sink heats up too much, fuse will open and save the module.

Response

Your fan probably shorted out. Once that happens, it is a lot of time looking for fan motors too. One failed while I was at work and the leads to the junctions melted and that was the end of that cooler. put a thermal fuse in series with the power supply. clip the fuse to the heat sink. If heat sink heats up too much, fuse will open and save the module.

The cooler under consideration really did not have room for that. Further, you would need to experiment to get the right values, and guess, what, you would burn out junctions experimenting. But the person who posted that his cooler 'burned up' in 10 hours is not unique in that problem. Those coolers, regardless of who sells them, are very fragile and have no safety fallbacks. Most seem to have been designed for easy of production, not use, and function quite poorly. I took my Kooltron and had to modify it extensively to use a Radio Shack fan with ball bearings and extended life. Nevertheless, it is probably still a fire risk you would want to think about if using a 120-volt adaptor. I think the 'trucker model' sold at truck stops may well be better since they advertise extended life. Extended from 10 hours at any case, but how long I don't know.

Response

Uh, the fuse is built in to the "cigarette" plug on mine. And I have had Igloo send replacement parts for two different items I have had over time. The earlier poster was quite wrong when he said rudeness was business as usual for those folks. As always, YMMV Your fan probably shorted out. Once that happens, it is a lot of time looking for fan motors too. One failed while I was at work and the leads to the junctions melted and that was the end of that cooler. put a thermal fuse in series with the power supply. clip the fuse to the heat sink. If heat sink heats up too much, fuse will open and save the module. The cooler under consideration really did not have room for that. Further, you would need to experiment to get the right values, and guess, what, you would burn out junctions experimenting. But the person who posted that his cooler 'burned up' in 10 hours is not unique in that problem. Those coolers, regardless of who sells them, are very fragile and have no safety fallbacks. Most seem to have been designed for easy of production, not use, and function quite poorly. I took my Kooltron and had to modify it extensively to use a Radio Shack fan with ball bearings and extended life. Nevertheless, it is probably still a fire risk you would want to think about if using a 120-volt adaptor. I think the 'trucker model' sold at truck stops may well be better since they advertise extended life. Extended from 10 hours at any case, but how long I don't know.

-- "Government is not reason. Government is not eloquence. It is force. And, like fire, it is a dangerous servant and a fearful master." ---George Washington "In matters of conscience, the law of majority has no place." -Mohandas Gandhi "If you will not fight for right when you can easily win without bloodshed; if you will not fight when your victory will be sure and not too costly; you may come to the moment when you will have to fight with all odds against you and only a precarious chance of survival. There may be even a worse fate. You may have to fight when there is no hope of victory, because it is better to perish than to live as slaves." -- Winston Churchill on the eve of Britain's entry into World War II

Response

As far as temperature control goes, just get a thermostat out of a regular junk refridgerator and put it in the power circuit. For efficiency, you'd be much better off getting one of those little 1.7 cubic foot 110VAC refridgerators and running it off a 250 watt inverter. Q [This is x-posted to all the newsgroups I could think of with the knowledge base and possible interest in the topic. If you are uncomfortable, trim the headers, as I read all these groups for info.] Today, while cruising through Sears, I saw one Igloo Kool-Mate sitting on the shelf. (I was getting a couple of lightweight rod and reel combos, Zebco 202s, for a Crappie trip next weekend with the [commonlaw] wife.) Anyway, I got it on sale for about $50.00 and took it to the car. Plugged it in, and drove 40 miles total running it empty. It had cooled completely by the time we got home. I must say I was pleased. But ever looking for as much efficiency as possible, I have some questions. I got the thing for a remote cabin we have for weekend getaways. (I grew up on a dirt farm in ‘Bama, so Atlanta gets me batty!) Anyway, we are going solar out there, and refridgeration was a concern. After looking at all the hi-efficiency fridges, and gas models, I figured this would be a real good compromise. Now, we only store drinks, and a stick of butter we bring with us, and maybe some cheese or steaks or such, for the weekend. We keep the reefer we have now off during the week, empty, since we aren’t there. Now, I was figuring I could hot glue styrofoam sheets to the outside of the cooler, excepting the area where the vents, fan and power cord are, of course. The only problem with it I can find is that it is a continuous use heat pump, with no auto shut off. According to the spec but it could be better. Now, I have a few other ideas to bounce, let me know what ya’ll think. Adding a digital thermometer to the inside, with the readout on the door. Anyone know if I can wire the thermometer to a relay, so that it will shut on and off automatically when the temp. reaches a cutoff and cut-on point? I figure the mods aren’t that difficult to make, especially if the thermometer has an alarm for a high and low temp. Run the alarm wires to a relay switching power to the reefer on and off. All around, how’s it sound? And has anyone played with these before? Yes of course, I purchased mine with the automatic temperature control built in, several companies supply them that way and also as food warmers. Which only requires reversing the polarity to the thermoelectric module. If you real want to be efficient do not glue anything to it. Instead build a air tight insulation box to place it in, with a two hinged doors. One to get food and the other to allow air flow when you are operating it (absolutely necessary or it will over heat and be destroyed. When it is cold enough turn it off and close the door it will stay cold for a day if you don’t open it. Never palace warm food in it if possible. It takes more than a day to completely cool a full cooler with warm food. If you don’t shut of the air flow it will warn up the external heat sink then the thermoelectric module and then the heat sink inside and eventually the contents. These coolers are designed to keep things cold and have limited cooling power only about 50 degrees below the outside air cooling the heat sink. You can get them to freeze the contents if it is cool enough at night or place ice or snow near the air cooling it.

– POWERCHUTES.COM http//www.powerchutes.com

Response

I think the ‘trucker model’ sold at truck stops may well be better since they advertise extended life. Extended from 10 hours at any case, but how long I don’t know.

I drove a big rig for New Prime Inc. out of Springfield, MO. for a while and during three months of constant 24 hour a day running my partners cooler never had a problem. I don’t recall the brand name but he paid 89.95 for it at a truck stop and it came pre-wired for 110 volts (we had a built in invertor, in the truck). We used it as a small refridgerator, but we had to be careful not to accidentally freeze items.

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I have tested both units, an 80 watt 110VAC refridgerator with a 500 watt inverter as well as the KoolMate and these are the results I found The 80W refer worked much better as far as making ice and keeping things cold. It ran on my batteries for27 hours before the inverter shut down at 10Volts. however – The Koolmate continued to run for several hours longer because I allowed it to stay connected until the batteries discharged to 5 volts. It does not make ice but, if kept out of the sun will keep a drink cool (not icey cold). conclusion – I will keep the little fridge! The Koolmate I will keep around for use if the little fridge ever goes kaput. Shep PS I also have a free conversion of a small B&S genset to propane. Will tell my secret to anyone who e-mails me and asks for it. I converted my 3.5 horse for free, no gadgets or carb needed! As far as temperature control goes, just get a thermostat out of a regular junk refridgerator and put it in the power circuit. For efficiency, you’d be much better off getting one of those little 1.7 cubic foot 110VAC refridgerators and running it off a 250 watt inverter. Q

Response

I have tested both units, an 80 watt 110VAC refridgerator with a 500 watt inverter as well as the KoolMate and these are the results I found The 80W refer worked much better as far as making ice and keeping things cold. It ran on my batteries for27 hours before the inverter shut down at 10Volts. however – The Koolmate continued to run for several hours longer because I allowed it to stay connected until the batteries discharged to 5 volts. It does not make ice but, if kept out of the sun will keep a drink cool (not icey cold). conclusion – I will keep the little fridge! The Koolmate I will keep around for use if the little fridge ever goes kaput. Shep PS I also have a free conversion of a small B&S genset to propane. Will tell my secret to anyone who e-mails me and asks for it. I converted my 3.5 horse for free, no gadgets or carb needed! As far as temperature control goes, just get a thermostat out of a regular junk refridgerator and put it in the power circuit. For efficiency, you’d be much better off getting one of those little 1.7 cubic foot 110VAC refridgerators and running it off a 250 watt inverter. Q

Don’t take deep-cycle lead acid batteries down that far. Once you get to 10.5 volts on a 12V battery stop. Cared for a deep cycle lead acid battery will give you 400-600 cycles. The “cutoff” feature of the inverter is a feature, not a bug. Drop below 10.8V and you will be lucky if you lose only 1/2 of its capacity and get 10 more cycles out of it. BTW, don’t use plain starting batteries for this type of work, normal starting batteries are great for short, heavy loads, but if you use more than 5-10% of their capacity you rapidly diminish their lifespan. –

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As far as temperature control goes, just get a thermostat out of a regular junk refridgerator and put it in the power circuit. For efficiency, you’d be much better off getting one of those little 1.7 cubic foot 110VAC refridgerators and running it off a 250 watt inverter. This causes thermal fatigue, on the peltier device. If you do this, put a resistor in paralell with the switch, so that it allows around half the rated current to flow. (Don’t forget to connect the fan to the supply before the resisitor.

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For efficiency, you’d be much better off getting one of those little 1.7 cubic foot 110VAC refridgerators and running it off a 250 watt inverter. This causes thermal fatigue, on the peltier device.

Huh? If you do this, put a resistor in paralell with the switch, so that it allows around half the rated current to flow. (Don’t forget to connect the fan to the supply before the resisitor.

Right. Controls the Unseen Forces. Nick

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shadow laughs. you need to read about peltier junction coolers. There is a limit to how cold they will get your igloo coolmate. It is possible to hook them up in series and get an actual really cool refridgerator or freezer, but you are better off getting a small refridgerator instead if you are going to do that. your concerns about putting a thermostat on it to shut it off when it gets cold are not really a problem. the thing will never get that cold that you will want it to shut off unless the ambient temp is kind of cool to begin with. check out the manual that came with it….it gives a list of the ABSOLUTE coolest the inside will get depending on the ambient temperature. its a usefull toy, and i have camped with one for years, but quite frankly i gave up and just bought dry ice when i was going to be out for more than three days at at a time, and regular ice for periods less than that. i KNOW it violates the principle of making an alternative source of refridgeration to do that. If you are REALLY interrested in a peltier cooler refridgerator, i suggest you do a web search, or better yet, go to the nearest magazine store, and buy a copy of the magazine “nuts and voltz” In their advertizement section (the whole thing is basically advertizements) they have peltier cooler assemblies for sale cheap. you can make your own refridgerator out of them easier than modifying the coleman coolmate. i did the above and had better success with it than the coolmate. but i was only playin around and i took the junctions apart to use them for cooling the chips in my computer (thats why nutz and voltz sells them) so that i could overclock it. (pentium 200 running at 400 mhz….hehe) shadow laughs. the space shuttle uses peltier junction coolers for its perishable items. I am not sure what set up they have but i do know that it isn’t cold enough to actually freeze anything. I believe that to do that, from what i was looking at, in any reasonablly speedy time frame, you would need, get this someplace around 11 or more peltier junctions cooling in series….three then two then one, of course you could do it in other ways, but it certainly isn’t efficient if you are planning on using a lot of food from the fridge quickly….i still like the idea but it isn’t a panacea.

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