Looking into the battery future
I do not need a crystal ball to know battery related headlines that will be hitting our screens during the coming year: ‘Get More From Your Battery’, ‘New Battery Charges to 85% in ¼hr Using Renewables’, ’Breakthrough in Extended Battery Life’ or ‘WizzoXzX Hampered by Poor Battery Performance’, ‘User Arrested for Stealing Electricity to Charge Phone’, or a combination and variation on these themes.
You cannot really blame the headline writers, these are the problems that have been associated with battery powered portable equipment right from the start. Yes, they grab the attention of the reader, but it is rare to find an article that really justifies the headline. Too often the article is a recycling of already established ideas, or a research programme that will take many years before it escapes the development laboratory.
Only a couple of days into the new working year I had a contact email me an article asking for my opinion on its contents. ‘New (kit) charges internal battery to 80% capacity in <½Hr from built in solar panels’ the headline proclaimed. Now that is a headline that does nothing for me, 80% of what? Although a theoretical run time for the kit was given, this was presented in a way the suggested that this was from an add-on external pack. The problem with the article was that no details about the capacity of the internal battery was given. And this was without considering environmental conditions
Battery Charge Efficiency, Nothing New
The reality of the article was that it was not reporting on a new technology breakthrough. In practice even old generation Lithium Ion and derivative type cells/batteries have very good charge acceptance figures, typically 90 to 95% especially during the early phase of charging. If you are charging a small lithium ion cell with a capacity of a 200mAh, charging to 80% capacity is 160mAh. Allowing for typical charge acceptance efficiency, this battery will only need a 1.5W output solar panel (approx. 120cm²) to charge as per the headline, hardly ground breaking!
It is not about the battery
This example shows up the real problem, it is not about the battery but rather how it is used and specified. Imagine how efficient your car engine would be if the available energy from the fuel you put in was 90% plus! Your typical Lithium Ion cell with and in/out efficiency at this level is clearly not the problem. Even if a new technology battery appeared that could take charge faster, or doubled the capacity in the same space, the limit would still be the provision of sufficient energy and power to charge in the specified time.
After all was said and done, I reported back to my contact that there was nothing wrong with the article, it was just that it did not really tell anything that was not already known. There was no magic, no technology breakthrough, just a lithium ion cell doing what it does best – accepting charge efficiently!
Battery Power Solutions
This example shows how it is important to look behind the headlines. The headlines may look enticing, but there is no substitute to having someone who knows the battery world inside out to advise you on your battery power source solution.