The problem and why it matters:
Lithium batteries lasts way longer when the charge level is limited over the service life of the battery. Batteries will also wear while not in use, so leaving a battery at a high state of charge will increase wear exponentially. This is a fundamental characteristic of lithium batteries. Keep in mind that the degradation of a battery starts the second the battery leaves the factory. And while it degrades the capacity will gradually be reduced. You want to slow down this process as much as possble not only to prolong longevity but also to maximize the energy capacity (which obviously directly translates to battery life/recording time per charge). More on this in the reply to this post below.

Battery longevity can be prolonged several times over by treating a battery properly, mainly managing thermals and limiting upper charge limit (lower limit also matters to an extent). This is well-documented and statistically confirmed many times and the scientific consensus on this matter is crystal clear. For this reason I do not see the necessity to provide sources as this is widely known in the industry and easily verifiable by looking up scientific publications online.

This matter becomes even more important when batteries are not user replaceable or serviceable. Very few customers will take their electronics apart and perform repairs or for this possibility to even occur to them.


This option is important regardless of use-case, but even more beneficial for certain users:
Some users have power constantly supplied to their cameras. Others frequently use battery modules that continually maintains the state of charge level on the camera module at 100 % as programmed by the firmware. There will also be people who simply want to prolong the life of their cameras no matter their use pattern. Especially when the battery is not user-replaceable. Even lowering the limit slightly will have a meaningful advantage. The health degradation is exponentially worsened the closer towards 100 % state of charge it is subjected to as well as the time spent at this given state of charge. In short, the choosen charge pattern of a battery is a compromise between capacity and longevity.

Either way, this should be a choice for the individual users to make. The advantages speaks for themselves.


This does not have to come at the cost of maximum recording time in the field:
DJI Action 2 is an example of a camera that supports battery modules. When you connect such a module it will charge the camera unit to 100 % and maintain that charge level. If you limit the upper charge level you will still be able to take advantage of the energy stored in the battery module but at the same time prolong the life of the camera. As this would be optionally configurable, users could decide for themselves whether they want the default behaviour or not.

In some scenarios some users might prefer to use the charging module simply for filling up the camera unit with as much energy as possible as to maximise recording time without the module. FPV and weight concerns comes to mind. However, many users, like myself, mostly use the camera with a constant power supply or using the power module in a dual module cage.


Other possible advantages:
For scenarios where the recording time is limited by thermals, reducing the heat generation from the battery and charging circuitry may contribute to increasing the recording stamina (this may be part of the reason why the recording time for Action 2 is longer with a power module connected). The less heat generation inside the unit, the better is the cooling solution able to cool the internals. Depending on capability this may also be helped by optionally configure the device to only ask for the energy it consumes and let the battery be unused. The reasoning for this is that this will avoid the heat generation from battery discharging as this heat generation will be shifted over to the external USB-power supply or battery module. Whether this is technically programmable via firmware with the current hardware design is something DJI engineers know.


Which devices will benefit from this feature:
Any device with a lithium battery.


How the solution should be implemented:
The user should be able to specify a percentage value for when the camera will stop charging. When it reaches this level it should discharge for a certain percentage values before starting to charge again. This value should preferably be adjustable as well. Especially when considering use-cases where the device is always plugged in (for example motorsport applications). Settings are optional, so the more the merrier. There should also be a mode where the firmware will limit the internal heat generation from charging and battery discharging, preferably with a lower limit (this will ensure a minimum state of charge is achieved regardsless of which energy consumption mode is enabled).

Obviously, the upper charge limit is the most important setting of them all, but it would also be beneficial to see the other options implemented as well.

For people wanting more information on how they can prolong the life of their other lithium powered products:
Note that not all products provide the user with preservation settings and the state of charge percentage level vs physical energy is defined by the manufacturer. An example of this is modern phones showing 100 % when in fact it is not actually at 100 % (I do not have a list over all phones that are programmed like this). Batteries wear in an S-curve. There is an initial degradation which levels out and slows down and after a certain amount of service life it will accelerate again. At this point, the battery is likely nearing its end of life. The industry standard for a dead battery is 70 % and it is not uncommon for batteries to be unreliable and volatile in its behaviour when it is quite worn-down. The degradation does also manifest itself as a reduction of total capacity. This is gradual from the second the battery leaves the factory and accelerated depending on environment and useage.

Warning about buying so-called "new battery": It is extremely common that used batteries are re-branded simply by putting a new sticker on as well as resetting the BMS (batteries usually have a little brain with a memory that keep track of cycles and wear as well as having certain protection behaviours). So buying replacement batteries is hard as it is super difficult to find actually new batteries and also original ones with the same properties. Many of such batteries sold are already pretty much used up.

Electric cars generally have a small percentage reserve at the top and bottom that is not useable. This is specifically to prolong battery longevity. This does vary depending on the model. Some cars have charge limit settings.

Business-grade or prosumer laptops generally let the user set these limits either in the BIOS or via their software suite. In Linux, which does not have the limitations of Windows in this regard as Linux is generally more customizable, this can (not always) be configured via the terminal or via system settings (KDE Plasma has system settings for this and I know there are GUI-solutions for Gnome and other environments).

For Android it is configurable via ADB on rooted devices only, or provided as an option on Sony-devices. I know Samsung has a few devices with some basic battery preservation settings but as far as I am aware only Sony has done this properly. Without root and OEM-provided settings you will have to use something like AccuCharge which sound an alarm at a user-configured charge level (similar software exist for Windows). I have used this solution on Android for years and it has no downsides for me personally. For iOS users, you will have to use a charge level alarm solution. As far as I know there are some basic settings in iOS that are better than nothing. Similar to that of Android in many phones.

There are also hardware-based products like Chargie that help you set a charge limit when otherwise not configurable.

Thank you for your feedback. I will take this as a suggestion of yours and will forward it to our designated team for attention. Rest assured that we are doing our best to gather customers' inquiries and work on solutions to provide the best customer service to our consumers. Thank you for your understanding and support.