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Graphene Batteries

Posted: 15 Oct 2020, 12:51
by John Mcnamara
I have used Turnigy batteries with good success over the years. At the beginning they were relatively cheap and proved to work well. They may not have lasted as long as some of the older brands I had used, but they were a fraction of the price. I had been using some 6s 5000mAh batteries in my Miss Wind biplane and they were getting tired. I had no complaints after several years of service, so when I built (that is a wild exaggeration really. Threw some servos and glue inside, then shook for two minutes is more like it) I look for some exact replacements. I realised that two batteries in series would provide the 12S battery I needed for this model. So, I went online to find that they had been replaced by Turnigy Graphene Batteries at a much higher price. Still, given god previous experience and having read the blurb about how good they were I took the plunge.
They had much the same size and weight but apparently a much better C rating. I had heard that you needed to treat them gently at first so I did a run in process for several cycles.
What a disappointment they have been. They provide less power than the cheaper earlier version and they cost far more. To add insult to injury, flying my miss wind biplane the other week I was suprised when one 6s 5000mAh battery was depleted after just 3500mA had been used. I have an alarm set to 4000mA's and I normally Have power to spare. Despite always doing a balance charge on every charge, one cell showed up as very low and continual balancing has not recovered the cell.
I have subsequently heard from a source in the electric flight competition scene, that it’s has been shown that there is in fact no Graphene in these batteries at all! If this is true, then it’s a scam plain and simple.
I was advised by the same source to buy from MyLipo.de. I have done so for some 3s batteries. The early results have been superb, and I intend to go back for more.
Avoid Turnigy Graphene guys. They are a waste of money.

Re: Graphene Batteries

Posted: 15 Oct 2020, 13:11
by Cliff Evans
Thanks John.

Re: Graphene Batteries

Posted: 15 Oct 2020, 15:17
by John Mcnamara
My Pleasure Cliff. I was just thinking Power batteries for up and go and FES systems is a potential topic in its own right. It would be good to know the results other have got, good or bad, especially with the bigger batteries, Its damned expensive when you get it wrong. What do you think?
John

Re: Graphene Batteries

Posted: 15 Oct 2020, 16:44
by Cliff Evans
There are a few members on here that would be good to advise on batteries, it's always been a tricky subject for me, I used to pick Gordon Tarlings brain a lot but, he seems to have disappeared shame, he was very knowledgable. As I say, Pose the questions, there are a few that are in the know and would I am sure, be glad to help.

Re: Graphene Batteries

Posted: 15 Oct 2020, 23:03
by Jolly Roger
Anecdotally, I have used mostly Hyperion Lipos from 3s to 5s (and in series as 10s) and found they give good duration with reasonable cycle life. Not the cheapest, but I look out for sales at Robotbirds to get decent deals.
I tend to draw not much more than 10C current, so my 4500mAh cells are only propped to take 50A max.
My general approach is to get the power I need by increasing voltage (by adding cells) rather than increasing current draw.

Re: Graphene Batteries

Posted: 17 Oct 2020, 12:45
by John Mcnamara
Hi Cliff,
Right I will do that.
You are right about Gordon Tarling. He was the Guru on the subject. Back in the 80's he and I used to co-operate on electronic design for ESC's and Chargers. I still have one of those chargers. Only good for Ni-Cads, 'cos thats what we have back then.
Roger,
Yes that is the way to go. The lower the current, all else being equal, the lower the losses.
John