Why Is It So Difficult to Produce High-power 12V PTC?

12V 300W PTC Heater can be produce and High Power 12V 600W PTC Heater is Difficult to product

Last time we introduct "12V or 24V Parking Air Conditioner (V-Cool 26) add PTC heating is Okay?" we said it is okay, but when we prepare to install and find out the right 12V PTC and find there some questions make it is difficult to produce and cannot used for parking air heater, of couse at our test result 12V 300W PTC heater is no problem (please see the follow test results), we can produce it, but if 12V 600W PTC heater there have some problem now cannot soulution. by the way, 24V 800W we used for 24V parking air conditioner is no problem, Please see below for the specific reasons why it is difficult to produce 12V PTC heaters
 

The 12V 300W PTC Heater test results are as follows from VehicleAC‘s Technical Engineer:

1. The power is 224W at the specified wind speed (5.5m/s),
2. The power is 291W at low wind speed or no wind,
please know the above, thank you!
 

Technical Barrier: High-power 12V PTC In a Negative Heat Working Environment

Today, the technical engineer of 12V PTC from VehicleAC explained to me a technical barrier why low-voltage 12V PTC is not easy to do: because under normal conditions, the power of PTC with wind is 1~2 times higher than the power without wind, but this 12V PTC voltage dut to its voltage is too small, and if the wind speed is high, so the heat carried away by the wind speed is larger than the heat generated by the PTC itself. This causes the 12V PTC to be in a negative heat working environment, and then increasing the power does not solve the actual problem, but makes the current becomes larger.
 

The Resistance Must be Controlled within 5 Ohms, Which Makes It Particularly Difficult to Screen Out Suitable 12V PTC Ceramic Chips

Another problem with PTC production is that PTC low voltage ceramic chips are very difficult to screen. For example, the normal 110V~220V PTC, the resistance can be between 500~5000 ohms, and there is a 10 times error, while the low votalge 12V PTC has relatively high requirements for the resistance of its ceramic chips, which the error must be controlled within 5 ohms. Which results in a very low qualification rate of 12V low-voltage ceramic chips and very low production efficiency. the most important is that it's very difficult to screen out suitable low-voltage 12V PTC ceramic chips.
 

Comes from VehicleAC’s Partner Professional PTC manufacturers 

Professional PTC manufacturers who have worked with VehicleAC for more than 10 years reported that they have failed to screen out suitable PTC ceramic chips in many tests. The main reason is that the resistance of the ceramic chip exceeds 5 ohms, which makes it difficult for the 12V PTC heater to start. so there is particularly difficult to screen out suitable 12V PTC ceramic chips to produce 12V PTC heaters  

About VehicleAC Truck Air Conditioner Manufacturers

All of VehicleAC’s truck Air Conditioner made in China have high quality and competitive price. So we are looking for truck air conditioning system dealer, to sell our rooftop 12v 24V truck air conditioning and tractor air conditioning in your local areas, furthermore please apply to join VehicleAC truck air conditioning dealer system for greater support, Interest please contact us by eamil info@vehicleacparts.com !