RC-Hangout

Just read about this, sounds interesting.

http://www.tomsguide.com/us/solidenergy ... 23242.html

http://www.networkworld.com/article/310 ... onics.html

http://news.mit.edu/2016/lithium-metal- ... onics-0817

Interesting. They say they're planning to use them in "drones" (sounded like commercial scale, not necessarily DJI phantom sized consumer level models). With the higher energy density and the typical reactance issues of lithium-metal batteries, I'm wondering how well these react to punctures, dents, and other damage compared to Li-ion. The articles indicated they were just as "safe" as li-ion, but that seemed to be a statement relating to random phone and laptop fires and overheating issues that have happened before, vs actual resilience to physical damage.

Still, has some promise. If they're considering these for drones then they may well be able to deliver the kind of currents our models desire. And safety wise, even if for hobbyist uses they end up having to go with a slightly bulkier cell package to provide additional protection against shorting, still would be a boon to the market.

On a side question: Anyone trying out the new graphene packs HK started selling a few months back? Any results you want to share with us?

I've seen a few videos of the new Graphene batteries. Maybe guys are liking them but I did see this one video of a guy that seemed to be real experienced with electronics, batteries, and battery composition. He took the Graphene battery apart and he mentioned that there really wasn't anything special about the Graphene battery guts in comparison to a LiPo battery. Now, is that really true? Who's to say.

pvolcko wrote:On a side question: Anyone trying out the new graphene packs HK started selling a few months back? Any results you want to share with us?

I almost threw a couple in to my last battery order but I just didn't have enough money.

I know one person using them (3s 2200mah size). They seem to be heavier than comparable packs, and a little smaller. He's flying in foamie aerobatic planes, so not a huge current draw compared to helis and racing quads. HE seems happy with them in his application. I'd be interested to hear what people think of them in more stressful applications though.

pvolcko wrote:I know one person using them (3s 2200mah size). They seem to be heavier than comparable packs, and a little smaller. He's flying in foamie aerobatic planes, so not a huge current draw compared to helis and racing quads. HE seems happy with them in his application. I'd be interested to hear what people think of them in more stressful applications though.

I will be getting some in my next battery order, but that may be a while away.
Here in New Zealand our only real option now is to get them from Australia. (Or pay 3 times as much and buy local.)
They have to come by boat so the shipping is not cheap and it takes a while so we have to get as many as we can afford at once.
On the up side, shipping cost is for up to 30kg so if we get enough at once the shipping is cheaper when split.
The problem is being able to afford up to 30kg of batteries.

Man, I'd be finding some buddies or clubs and getting group buys going if that's how you have to do things. Wouldn't think shipping from Australia to NZ would be that bad.

I think this is the video of a guy that I was talking about above. He tears a Graphene battery down and gives his thoughts. If you have about 10 minutes to watch this......

https://www.youtube.com/watch?v=fBy4eoDVp_g

He tore apart a battery. Did no analysis of either behavior (charge/discharge/IR/temperature measurements) or the materials (layer composition, electrolyte composition, etc.). No layer count or measurements to compare against another battery's cells.

The graphene thing may be marketing BS, but this doesn't answer it. He poo-poos it based on his visual observation of the materials as he rips it apart, but it also doesn't seem like he knows what he's even looking for or if he should be able to "see" something different. Perhaps he was expecting some visual difference to jump out at him, but if the normal layer material composition is black and he isn't going to throw some electrolyte under a scope, I'm not sure what he was expecting to see.