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Unread 10-12-2013, 20:13
yash101 yash101 is offline
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Re: Battery powered raspberry pi

Quote:
Originally Posted by efoote868 View Post
Added emphasis, as this is a point I'd like to address. One reason in particular that FIRST would be fine with having extra batteries integral to COTS components on the robot vs. teams fabricating their own devices with "integral batteries" is because there is already an element of safety to COTS devices.

A laptop or tablet manufacturer will have already designed out the risk to the lithium batteries in their device; they will have dropped and kicked and abused the devices to the point of failure many times over to ensure it is safe for the end user. While putting their device on a FIRST robot might not have been their intent, the forces involve should be pretty similar to the abuse the device will take in the real world.

The manufacturer is confident enough in their device that they're willing to take on liability when selling it.

Yash, you might be excited to take on the challenge of designing, prototyping, manufacturing and selling this device. You need to appreciate how dangerous lithium batteries are. Even if you pick a different chemistry, safety is still a very real concern for any electrical circuit. So much so, that you may even succeed in everything you do - build a working prototype, design it for manufacture-ability and all that, only to find that no one wants to take the risk in selling your device, so it never becomes COTS.

Just a heads up.
Yeah. Thanks. I was thinking about starting with NiCad/NiMh, because it is hard to overcharge them to the point of explosion. I can have an MCU charge the battery to 95% and then put a very small amperage into the cell, to top it off slowly! I think that it still would be better to use a supercapacitor, with a tie resistor to discharge it automatically! I would like to test safety by: running it in a nitro rc car at top speed and ramming into steel (Bye bye, expensive RC car ), and hitting it with a hammer with a force greater than any robot would receive! Also, I would like to short it out and see what will happen. Also, I wish to seal the case with some sort of rubber or teflon, etc. so no metal shards will get in. Also, there will be a fuse soldered onto the battery pack!

Basically, I want to torture the device with a greater torture than what could be received by the device under the worst case!

I just thought, how should the power be transmitted to the SoC? Should I have a USB port? A miniUSB for the chip, debugging and configuration (like output voltage, preset to 5V), and a USB A Female to power the Pi?

Last edited by yash101 : 10-12-2013 at 20:17.