How much airflow is actually required for a 3696 LiPo pack?
How do you hold the pack in place with room for airflow? I assume velcrow so you can remove it to charge?
Thanks.
Battery Ventillation
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In most cases that I've seen, folks are using Velcro on one side of the pack to hold it to the fuselage. This leaves three sides free for air circulation.
The rule of thumb that I know about for air cooling is outlet area = 2xinlet area. That being said, there is always too much or too little of a good thing, e.g 2 times zero is still zero. The two items producing heat in the system are the battery and the ESC. The more you stressthem, the more heat they put out, then the more cooling airflow you need. My He-219 battery compartment has about 1/2 sqin inlet and about 1.5 sqin outlet, but I am barely getting the 2250 25C battery warm drawing 14 amps. If I over rev the 2908 above 16 amps, the ESC and the battery get very warm, so the Dauntless and Zeros have about 2 inches of inlet and about the same outlet, which seems OK for 16 amps, but if I over rev to 20 amps you can feel the heat through the foam (and it will potentially fry the 8C battery).
So, the answer to your question is the standard consultant's answer: "It all depends ...". It depends on the heat load you are trying to disipate, and some of that will come from trial and error with your selected components.
The rule of thumb that I know about for air cooling is outlet area = 2xinlet area. That being said, there is always too much or too little of a good thing, e.g 2 times zero is still zero. The two items producing heat in the system are the battery and the ESC. The more you stressthem, the more heat they put out, then the more cooling airflow you need. My He-219 battery compartment has about 1/2 sqin inlet and about 1.5 sqin outlet, but I am barely getting the 2250 25C battery warm drawing 14 amps. If I over rev the 2908 above 16 amps, the ESC and the battery get very warm, so the Dauntless and Zeros have about 2 inches of inlet and about the same outlet, which seems OK for 16 amps, but if I over rev to 20 amps you can feel the heat through the foam (and it will potentially fry the 8C battery).
So, the answer to your question is the standard consultant's answer: "It all depends ...". It depends on the heat load you are trying to disipate, and some of that will come from trial and error with your selected components.
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<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Ed Kettler</i>
<br />If I over rev the 2908 above 16 amps, the ESC and the battery get very warm, so the Dauntless and Zeros have about 2 inches of inlet and about the same outlet, which seems OK for 16 amps, but if I over rev to 20 amps you can feel the heat through the foam (and it will potentially fry the 8C battery).<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">So I would assume that batteries rated for a higher discharge rate will stay cooler at a given amp draw... Right now I am using 20C packs.
<br />If I over rev the 2908 above 16 amps, the ESC and the battery get very warm, so the Dauntless and Zeros have about 2 inches of inlet and about the same outlet, which seems OK for 16 amps, but if I over rev to 20 amps you can feel the heat through the foam (and it will potentially fry the 8C battery).<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">So I would assume that batteries rated for a higher discharge rate will stay cooler at a given amp draw... Right now I am using 20C packs.