Short answer: the YO DR-FW50 is a two-bay charging case, not a battery — it holds no charge of its own. Its job is to charge two NP-FW50 series batteries at once and, with the lid closed, to carry them as a storage box. Push each battery into a bay in the correct orientation and connect a 5V supply; the bays are managed independently, the battery loaded first usually finishes first, and once the indicator moves from “charging” to “full” you can take it out. Charging with the lid shut builds a little heat, so open it in summer or during back-to-back fast charges.
First-time buyers often assume it is a case with a battery inside and are surprised to receive an empty shell. So the positioning is worth stating plainly: it is an accessory for an accessory, and it serves batteries you already own. Before buying, count how many batteries you have; with only one, its value is mostly as storage.
The most accurate way to think of it is a battery box with a circuit in it. The shell is hard plastic, the two bays follow the FW50 outline, and each bay floor carries metal contacts and locating pins; the inside of the lid usually has a foam pad so the batteries are held still when it closes. Three sentences cover its boundaries:
- It is: a two-bay charger, a battery storage box, and a way to keep batteries organized on a trip.
- It is not: a battery, a power bank, or anything that can power a camera body.
- It cannot: charge an NP-FZ100 (the FZ100 is larger and will not fit an FW50 bay) or charge a phone.
That distinction matters, because “charging case” invites comparison with a power bank. It needs an external supply to work and stores no energy itself.
Reading the indicator lights
Light colors vary slightly between production batches, but the logic is consistent: one light per bay, using steady, blinking and off to express four things. The table groups them by function; for exact colors, follow the sheet in the box.
| Light behavior | Meaning | What to do |
|---|---|---|
| No light after connecting power | Bay empty, no battery detected | Check that the battery is seated fully and the contacts are clean |
| Blinking or pulsing steadily | Charging | Normal; wait |
| Turns steady | That bay is full | Remove the battery, or leave it in place |
| Rapid blinking or an unusual color | Battery fault, poor contact, or overheating | Remove the battery, inspect the contacts, let it cool and retry |
The key to reading the lights is to treat the two bays separately. They are independently managed rather than wired in series, so the left bay can sit steady while the right is still blinking; that is normal and does not indicate a fault. If one battery blinks for hours without going steady, move it to the other bay first — that quickly tells you whether the problem is the battery or the bay.
Charging order across the two bays
There are two common designs: both bays output at once and each proceeds at its own pace, or a primary/secondary arrangement fills the first bay before switching to the second. The DR-FW50 belongs to the independent group, so both bays run together, though differences in starting charge, internal resistance and age mean they finish at different times.
In practice, this order works well:
- Put the least-charged battery in the left bay. The left bay is often the primary one, and some designs give it priority on current, so starting with the emptier battery gets you a usable pack sooner.
- Load both batteries, then connect power once. Repeated plugging and unplugging makes the control circuit renegotiate and actually slows things down.
- Pull either battery as soon as its light goes steady. There is no need to wait for both; before an outing there is often only time to fill one.
If your habit is to plug in at night and collect both in the morning, order is irrelevant — both bays finish before dawn. Order only matters in the case of “two hours until I leave and both batteries are empty.”
Heat: why the closed lid runs warm
Both the batteries and the charging circuit generate heat, and a closed lid traps it in a small space where it escapes slowly through the shell. In winter this is a non-issue; in summer, or when charging two in a row, it is noticeable.
A few practical habits:
- Charge with the lid open when the room is warm. The lid is mainly for storage and dust protection; leaving it open while charging costs nothing and dissipates heat far better.
- Do not charge inside bedding, on a sofa, or in a bag pocket. These are the places where heat cannot escape, and where problems are most likely.
- Unplug if it feels genuinely hot to the touch. Normal charging is warm; if you feel you need to move your hand away, the ventilation is inadequate.
- Do not charge a battery straight off the camera. A battery coming out of a body is already warm; give it ten minutes or so before it goes into the case.
One clarification: heat during charging is normal physics for lithium batteries, and warm does not mean faulty. The signals to act on are “too hot to hold” and “accompanied by a smell or swelling” — the latter means stop using it immediately.
Everyday use and storage
Storage is the case’s second job. Two batteries and a case are far easier to manage than two batteries loose in a bag: no keys or coins scuffing the shells, and no contacts shorting against metal objects. Closed, it is roughly the size of a cigarette pack and fits a camera bag’s front or side pocket.
For long-term storage, leave the batteries at five or six tenths of charge before they go in, rather than storing them full or empty. On travel and security checks, see the rules for carrying lithium batteries with you (the same rules apply to the FW50). The body compatibility list for the batteries themselves is on the TNP-FW50 category page; if your batteries are the USB-C versions, case charging and direct charging can run in parallel, as described on the NP-FW50 battery page.
FAQ
Does the DR-FW50 include a battery?
No. It is an empty case and you supply the NP-FW50 series batteries. Confirm you already own batteries before buying, because the case cannot be used on its own.
Can it charge one TNP-FW50 and one genuine FW50 at the same time?
Yes. The bays are managed independently, so mixing is fine and each battery’s progress is judged separately. They simply finish at different times because of their different ages.
Can the case charge the FZ100 battery used in the A6600?
No. The FZ100 is larger and will not fit an FW50 bay, and the contact layout differs. The A6600 belongs to a separate battery system.
Is it safe to charge with the lid closed?
Under normal conditions, yes — the case is designed to be used closed. In a hot room, on bedding, or inside a sealed bag, leave the lid open and make sure air can move.