Originally Posted by
GrumpyDiver
Cameras use a particularly tricky breed of batteries - Lithium ion (Li-on) for short. Lithium is an extremely reactive metal, i.e. it bursts into flames in the presence of oxygen; there is a reason that commercial airlines do not transport them; there have been a couple of fatal crashes where Li-on batteries have been identified as likely culprits and there have been some instances (check YouTube) where there have been runaway thermal incidents with these types of batteries, destroying the laptop, cell phone, etc. This is one reason you are legally not allowed to have these batteries (including equipment with these batteries installed in them) in your checked luggage as any fires they cause would go unnoticed until it is too late to react.
They also have another "issue", thermal runaway when charging to quickly. This causes heat and the battery housing can be breached, exposing the lithium to oxygen in the air causing a fire. Li-on batteries are supposed to have circuitry built into them to monitor and prevent thermal runaway conditions during charging, but this all costs money, so there is no guarantee that the no-name batteries have these safeguards built into them.
So, am I going to save myself a few dollars by going to batteries that are not backed by the manufacturer? No, not with a $3000 camera body. To me, it's not worth the risk. I do know that both Sony and Nikon have had recalls on Li-on batteries for safety reasons. I'm pretty sure that this isn't going to happen for the low cost "alternatives", just because the controls that that the manufacturer and distributor has are likely to be fairly weak.
I've seen some reports that Panasonic cameras communicate with the batteries and if the battery cannot be authenticated, the camera will refuse to turn on. While many will see this type of approach as being one to sell more branded batteries (and there may well be a component of that), there is also a liability aspect involved. Any camera manufacturer could incorporate similar functionality into the camera's firmware.
When it comes to Li-on batteries, there are inherent risks that other battery types do not have. They are light weight and have high power densities, but this does come at a price.