Powering Peltier with LiPo battery

[dansteinb]

I'm looking to build a peltier that is powered off of a LiPo battery
I don't need it to cool/heat more than +/-10C ambient and then I want to be able to adjust the temperature to less than that differential

The peltier I'm thinking about using is:
https://www.digikey.com/product-detail/en/marlow-industries-inc/NL1025T-01AC/1681-1032-ND/6159080

The LiPo I'm thinking about using is:
https://www.digikey.com/product-detail/en/adafruit-industries-llc/2011/1528-1857-ND/6612469

How do I limit the current going into the peltier? I don't think that a resistor could do the job and it would be burning off a significant amount of heat but I'm new to this.

How do I get the temperature to adjust up and down?

I'm also considering using a fast discharge LiPo to give the peltier the full current it needs but I would still want to limit the temperature given off of the peltier to be between +/-10C ambient. Could this be done using PWM? Are there circuits that already perform this function or would I need to go the microcontroller route and use power FETs to do the switching?

 

[KlausST]

Hi,

For best performance you should use
* DC instead of PWM (not pulsed, not ON/OFF)
* a switched mode controller instead of linear current regulator
* current control instead of voltage control

Did you do a search for suitable circuits?

About the temperature regulator:
There are many options, depending on your requirements.
* absolute temperature control / difference (relative) temperature control --> 1 or 2 temperature sensors
* what human interface? Pot, Led, PC, display, keys...
* regulation speed, accuracy
* what are you trying regulate? And by what values (error) is it influenced! (Ambient temperature, load temperature, Q...)

Klaus

 

[dick_freebird]

Peltier coolers are current hogs and woefully inefficient.
Amp-hours divided by amps (as a function of heat flux
and temperature differential) will probably give you a
less than encouraging number for run time. Do not neglect
the fan which has a key role (holding down hot face temp
is the single best thing you can do) along with a proper
heat sink / heat exchanger on the hot face.

 

[dansteinb]

The idea to have a device that can be held in the palm of your hand (assuming the use of a LiPo) that creates a cool enough temperature on one side that is very noticeable to the user (let's say 10C below ambient). If a Peltier would be used then an added bonus would be that the user would feel heat on the other side of the device. The user would be able to adjust the temperature to a few different settings using a single button push.

If there is a more efficient way to cool this?