There have been a couple of Ultrabook battery-related news items in the last few months. Both, I believe, stem from what was talked about at Intel’s IDF event in Beijing. The first article highlighted how Intel introduced a standard size battery. The most recent article mentions the cylindrical 16650 type cell, a smaller version of the very common Li-Ion cell found in removable laptop battery packs. “Intel Hopes New Batteries Can Reduce Ultrabook Cost.” said the article title.
Most of what is going on is summarised in this slide.
What’s really happening here is that Intel had a room full of industry partners and took the opportunity to put their thoughts forward. Lets work with standard size cells. Li-Polymer (prismatic cells) for flat solutions and the new 16mm 16650 Li-Ion cylinder batteries for larger, lower cost solutions.
Intel also said that Ultrabooks need higher energy capacity cells with a longer life cycle and ability to deliver short-term high power bursts. They suggested that faster charge would be good too!
Makes sense, not news! I hope the room was listening and agreed.
16650 vs 18650
The 18650 3.7v cell must have sold billions. You’ll find it inside most laptop battery packs in 3, 6 or even 9-cell set-ups. Cheap versions don’t have as much capacity as expensive versions but the average 18660 cell delivers 2200mah. That’s enough to power an Ultrabook for web activities for about an hour – about 8Wh of capacity. There are 2400mah and 2600mah versions available too for another 10%-20% battery life. Panasonic even have a 3100mah version which uses their NNP technology. (Link) At 18mm, these are too big for Ultrabooks.
The newer 16650 is becoming available now in a 2200mah capacity. Given that the cell is 2mm thinner than the 18650, this is an impressive feat. However, prices are high compared to the 18650 and suppliers are limited. Sanyo are one supplier (part UR16650ZT) but there’s a 2400mah version listed on Alibaba that might not be from Sanyo. China BAK are said to be producing a 16650 too so maybe this is it. I couldn’t find it on their web page.
With a 2400mah battery at 40gm and 16mm you could quite easily create a 6-unit pack inside an Ultrabook and that’s a likely scenario for a decent capacity of around 53Wh, that same as you’ll find on the Lenovo U300s.
And there lies the issue. The 16650 isn’t going to bring you more capacity. 6-cells is likely to be the perfect balance between size, capacity and cost.
I track battery news closely and I do my research and testing. It’s the one component in a portable device that improves battery life with a 1:1 use ratio. Improve the efficiency of a screen by 70% and you’ll end up with, 20% real-world battery life improvement. The same with storage, etc. With a battery, if you increase the capacity by 100%, you get 100% more battery life.
It frustrates me that battery technology has been so slow. A 7% year-on-year improvement in energy density is poor, if not suspicious because it’s clear that a company producing batteries that are longer lasting, with more capacity is going to suffer! They’ll tell you that chemistry doesn’t permit big advances and to some extent it’s true because you can just build a new manufacturing plant and close the old one but we’ve seen so many news items about major breakthroughs in improvements to the current technology that you wonder why they’re not reaching the market. Here’s an article from today about a breakthrough at Washington State University.
We can’t expect major changes in battery technology due to the billions invested in chemical plants around the world but it’s reasonable to expect 15 or 20% per year, surely.
I wrote the same story in 2006 and again in 2007. Nothing much seems to be happening in the battery industry except tiny step improvements. In reality, that’s what’s likely to continue to happen unless someone steps in. Intel, their customers and their 300 million Ultrabook capital fund are the people to do this. Let’s get some action in the battery industry. Let’s get some transparency too.