Waeco Project Complete!

Submitted: Tuesday, Feb 08, 2005 at 13:00

ThreadID: 20235 Views:3412 Replies:4 FollowUps:9

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Member - Jeff M (WA)

Well I've finally finished my experiments-turn modifications to the Waeco 44L Cooler. (I know most of you probally have fridges and don't care, but for those poor buggers who either can't afford a real fridge or are not allowed to buy one this may be of some use).

Here's a Break down of costs:
Waeco 44L Cooler: $149
2 x 90mm 50CFM 12v Fans from Dick Smith $20ech $40
1 x 6amp Peltier Replacment Chip (Jaycar) $14.95
1 x Air Con Digital Thermostat (Jaycar) $30
1 x 12v Automotive Relay $5
Plus Misc wires, crimps etc etc.
TOTAL $238

Performance: Tested last night. Ran it off a 7amp 13.8V Power Supply.
Turned unit on at 7:40pm exactally.
Ambiant Temp and Inside Temp were both 22.1c
Run for 1 hour empty and checked temp's again at exactly 8:40pm
Ambiant temp had risen to 23.2c and inside temp was 8.8c
I went to bed and woke up this morning and the thermostat I installed was cycling the cooler between 4.5c and 7.2c
IMHO a success.

Process/Mods
Firtsly I took out the old peltier (3 amp module) and replaced with the 6amp jobby. Very simple, just undo the heatsink screws and it just slides out. Put some thermo paste on and re attach. Cut wires and solder new ones in place.

Secondly silicone around the bottome of the heatsink as the tape they used in the factory was crap at sealing inside outside temps.

Thirdly remove crappy pooh fan from outside heatsink and replace with 50CFM jobby. Then angle gride the heatsink on an angle and instert the second fan on the exaust vent and wire up.

Fourth Run main power through relay hooked up to Digital Thermostat and silicone thermostat to inside of lid. (gives you digital push button tempeture control).

Fifth: Plug in and put beer inside. Dink Beer and be merry. :-)

I'm assuming that with drinks etc inside the fridge's cycling temp will steady a little as the drinks etc will keep the temp more regular?? I think? Maybe I'm wrong. I can set the thermostat to cycle with a less difference, however I want the unit to be off for as long as possible between cycles to conserve battery power.

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Reply By: Member - Bradley- Tuesday, Feb 08, 2005 at 13:19

Tuesday, Feb 08, 2005 at 13:19

ingenuity, product improvement, personalisation,,,,, I LIKE IT.

Well done mate , sounds good, hope it works well under heavy testing (psssss glug glug)..

Now whats the power draw to the tenth decimal place ??? :-))

AnswerID: 97233

Follow Up By: Member - Jeff M (WA) - Tuesday, Feb 08, 2005 at 13:39

Tuesday, Feb 08, 2005 at 13:39

To be honest I'm not 100% sure on the power draw. I've tried hooking it up through my multimetre but it creates too much voltage drop. Because Peltiers draw more amps the higher the voltage is I'm not getting an accurate reading that way. But it's a 5amp/7amp@50% duty cycle supply and it's runningit well so I can only assume I'm drawing 7 amps or less. I am still getting some voltage drop off the power supply but I think that's to be expected while peaking it out as I am.
The advantage of the Peltiers is that they will naturally draw more power and cool better when plugged into the car because the voltage will be higher (around 13.8) but when you turn the motor off and setup camp the voltage (under load) will drop to about 12.1v or so making the Peltier draw less amps ergo conserving power. The flater the battery get's the less current it will draw. But having the digital thermostat means I can turn it right up at night and hopfully it won't run much at all (as long as it's not tooooo hot at night).

FollowupID: 355842

Follow Up By: Member - Bradley- Tuesday, Feb 08, 2005 at 14:51

Tuesday, Feb 08, 2005 at 14:51

i was only pulling your chain about the power, as some people will want to know the nth degree about it , but it sounds ok for what youve ended up with, not much to go wrong either. (and the price was right)..

ps - temp at night wont be the problem - how often the lid is opened during the night may be !

FollowupID: 355860

Follow Up By: Member - Jeff M (WA) - Tuesday, Feb 08, 2005 at 15:10

Tuesday, Feb 08, 2005 at 15:10

Yeah you gotta love solid state gear. I've even kept the other peltier chip, I should whack it in the with the car spares. Then if it ever carks it, in 10 minutes I can have the fridge up and running again!

It's amazing how much the temp rises by just opening the lid for a couple seconds. I'll just have to drink the long necks hey? :-)

Price, well yeah the missus was not keen on spending $1k on a fridge I can tell you!
It seems from what I've seen that it's pretty close to a 50or 60L compressor fridge inside too as the compressor fridges must measure their "litreage" including the compressor and electronic gear. It's the biggest peltier cooler I've seen on the market.

FollowupID: 355869

Follow Up By: Member - Bradley- Tuesday, Feb 08, 2005 at 18:19

Tuesday, Feb 08, 2005 at 18:19

i'll definetly keep it in mind for a future second fridge, cant go wrong for that price, got the 40lt engle which i mainly use as a freezer, but may need a dedicated fridge for future long trips.

BTW got the insulated fridge bag with the fridge but have since modified it by adding a layer of foil sided foam around the front and sides (foil side out), makes a big difference to running times, if you stick your hand between the fridge and the foam its pretty cold , other side is close to ambient. Before the foam there wasnt much cold between the fridge and bag, so it wasnt a very efficient insulator. Might be worth making up a cover out of this gear for yours, Clark rubber have it 20mm thick about 1.5m wide - cost me about $38 for a linear metre.

take it easy Jeff,

Hey next project, use that peltier chip, a ciggy lead and some alluminium to modify a stubbie holder. mmmmm icy drinks while driving :-))))

FollowupID: 355892

Follow Up By: Member - Jeff M (WA) - Tuesday, Feb 08, 2005 at 18:30

Tuesday, Feb 08, 2005 at 18:30

Well that's an idea, I hould go make a bag for it, that'd probally help heaps. Thanks Brad, next little project! :-)

FollowupID: 355897

Reply By: crfan - Tuesday, Feb 08, 2005 at 16:18

Tuesday, Feb 08, 2005 at 16:18

What about sticking the old peltier in the glove box to keep your chocy's cool.

AnswerID: 97262

Follow Up By: Member - Jeff M (WA) - Tuesday, Feb 08, 2005 at 18:25

Tuesday, Feb 08, 2005 at 18:25

LOL Good idea, but the only thing that fits in my glove box are the tyre guages and stauns and spare fuses! :-) Besides I don't think the ol' alternator on the surf can take much more!! Got so much crap hanging off it as it is. It's really struggles with the laptop and spotties going on top of everything else.

FollowupID: 355893

Reply By: REX.....(Adelaide) - Tuesday, Feb 08, 2005 at 18:00

Tuesday, Feb 08, 2005 at 18:00

just replaced the fan in my el cheapo no name brand cooler/warmer with a high speed one from a computer store works heaps better now within 15 minutes it was down around 10 deg normaly it would take twice as long

AnswerID: 97276

Follow Up By: Member - Jeff M (WA) - Tuesday, Feb 08, 2005 at 18:27

Tuesday, Feb 08, 2005 at 18:27

Yeah I toyed around with the idea of getting a computer radiator and coolant to cool the peltier, but came to the conclusion that for the extra $150 I could go out and buy a 3 way. Also then you'd have the problem of putting the radiator somewhere where it would't get damaged or blocked air flow.
It's amazing what difference there is between a good fan and a sht fan though hey!

FollowupID: 355894

Follow Up By: REX.....(Adelaide) - Tuesday, Feb 08, 2005 at 19:00

Tuesday, Feb 08, 2005 at 19:00

well i have a 3 way chescold goes well .
this little thing keeps the beer cold on those long trips hold a six pack and only cost me 30 bucks to buy

FollowupID: 355900

Reply By: Bob of KAOS - Tuesday, Feb 08, 2005 at 20:21

Tuesday, Feb 08, 2005 at 20:21

Jeff
very interesting and informative. I guess the critical issue is "will the beer be cold enough to drink at 6.00 pm when its been 30 plus outside all day?"

AnswerID: 97316

Follow Up By: Member - Jeff M (WA) - Tuesday, Feb 08, 2005 at 20:27

Tuesday, Feb 08, 2005 at 20:27

YES. That's why I upgraded it from the 3 amp to the 6 amp. Out of the box Waeco calimed that it was capable of 25 Deg C below ambiant. (slightly wishful thinking on their part IMO). So with the 6amper and better fans I'm hoping for cold beer at 6pm! ;-)

90% of the time we have been traveling for the most part of the day anyway with the air con on so ambiants should be fairly reasonable. The cooler should be able to keep it's temp under control until the sun goes down (while we set up camp etc) and then it'll be right as rain.
But even if I'm getting 27c under ambiant on a 30degree day that's allright.
The other thing I find that works absolute wonders are those ice packs (the soft blue ones). I whack a couple of them in their and they stay frozen for days in the cooler and keep the temps WAY down. With those packs in there (before I put the thermostat on) it would easily get into minus tempetures and start forming ice on the sides of the cooler.

FollowupID: 355921