Maxwell Ultra-Cap's/Lithium cells hybrid pack

[aqwut]

woah... 1 farad can be that small cap... that is cool

[BrianG]

Originally Posted by aqwut

woah... 1 farad can be that small cap... that is cool

Yeah, it is quite small. Because it is rated for such a low voltage, the plates can be very close together; and because the current rating is so low, the thickness of the plates can be ultra-thin.

I think that if I tried to use these, they would heat up and expand/pop before too long. Plus, if you look at the ESR, it is kinda high compared to caops designed for high currents...

[zeropointbug]

Have you ever had a cap blow on you?! I have, it's not fun, reverse polarity... the end vent opened right up, filled a large portion of my room with steam from the electrolyte. Very stinky :020: :036:

Ya, the new Super-Ubar-Ultra Caps from that group from MIT uses Nano carbon tubes like hair that drastically increase capacity and current. They claim 60Wh/kg gravimetric density. EStor, another company claim i think ~120-150 Wh/kg, IMPRESSIVE. For a capacitor.

[BrianG]

Oh yes, I've had a couple pop. One was because of too high voltage - I could actually see it expand until it vented. It happened before I could shut the power off. The other was from reverse polarity. That was a 1,000uF 50v cap in a power supply. Yes, they do stink.

[zeropointbug]

BTW, I now going to give in and get the DX 2 Spektrum Radio. I don't really like running out of room after one small town block. How are they for range?

[BrianG]

I've had good luck with my DX3 system. The range is about as far as I can effectively control it; ~100 yards at a guess give or take. Although, I always try to make sure the receiver is as far away as possible from the noisy motor wires to avoid potential interference problems.