Short answer: yes, you can mix them, and it will not damage the camera. The LP-E17 is a 7.2V, three-contact design, and the body reads voltage and temperature signals without caring whose name is on the label. The original at about 1040mAh and the T series tiers sit in the same range, so there is no electrical obstacle to using them together. What needs managing is not safety but the gauge jump that comes from two different discharge curves, and the rotation confusion that follows.
The physical boundaries of mixing
The body and battery communicate over three contacts: positive, negative, and a data line. The data line carries temperature and identification, and the body uses it to set charging current and the low-battery threshold. If a third-party pack is recognized normally, that communication works and the voltage is within the allowed range.
The protection board is a second layer. A reputable product guards against overcharge, over-discharge, short circuit, and over-current, and those protections are the battery’s own last line of defense, independent of the body. In a mixed pair each pack looks after itself; there is no circuit path by which one drags the other down.
Chargers can be shared. The original LC-E17 judges the charging stage by voltage, so any pack of the same form factor can use it. The T series supports USB-C direct charging and needs no dock at all, and the two replenishment routes do not conflict. Whether a dock is needed or can be shared is a matter for the product documentation and the charger markings.
So the claim that mixing damages the camera does not hold when voltage matches, contacts match, and the protection board is intact. The cases that genuinely go wrong are mostly unbranded products that omitted the protection board, or contacts with loose dimensional tolerances causing poor connection. Those are quality problems, not mixing.
Basic rotation principles
The core tension in mixing is that the remaining-charge number shown by the body does not mean quite the same thing for both packs. At the same two bars, the original might still deliver two hundred frames while the T series has eighty. Rotation should be designed around that difference.
- Charge both fully before you leave. Do not start with one full and one half. Inconsistent starting points are the worst thing about mixing, because every later judgment is distorted.
- Fit the smaller-capacity pack first and keep the other in the bag. That way the second half of the day runs on the pack with more headroom, and the finish is calmer.
- Do not wait for auto-shutdown. Swap at one bar and treat the remainder as a buffer rather than usable quota.
- Mark the pack you just pulled immediately so it cannot be confused with a charged one. A rubber band, a sticker, or simply inserting it the other way round all work.
- Charge both fully before storing them after the trip. Mixing makes “I thought it still had charge” misjudgments more likely, and standardizing on full removes that variable.
If the two capacities are far apart, say a 750mAh paired with a 1050mAh, adjust the plan again: put the small pack in the low-intensity stretches such as travel between locations, scouting, or around meals, and save the large one for the main scenes where you know you need output.
Why the gauge jumps, and how to read it
The gauge usually runs two logics at once: one reads voltage, the other uses a coulomb counter. The voltage method is simple but crude, and the reading changes as soon as the load does. The coulomb counter is accurate but needs several full cycles to learn a given pack’s real capacity.
Fit a pack the body has not seen before and the counter starts blank, so the body falls back to voltage estimation and the reading is conservative. It converges over a few uses, but alternating two packs keeps interrupting the learning, so the reading never settles as well as with a single pack.
What that looks like: three bars on insertion, two after a few dozen frames, back to three after a power cycle, and a low-battery warning that arrives without much notice. None of this is a fault; it is the estimator switching between two batteries.
| Symptom | Cause | What to do |
|---|---|---|
| Drops fast right after insertion, then steadies | Voltage estimation; sag under load is pronounced | Normal; watch the trend |
| Gauge recovers after a power cycle | Voltage rebounds when the load is removed | Trust the low-battery warning, not the bars |
| Shuts down abruptly at one bar | High internal resistance; fast sag under load | Move that pack to backup duty |
| The two packs lose bars at clearly different rates | Differences in capacity and curve | Rebuild the rotation around capacity |
A useful rule: when mixing, do not trust the bars, trust how much you have already shot. Set yourself a threshold such as swapping after a certain number of frames, and it will be far more reliable than watching the gauge.
Three situations where mixing is not advised
A one-off shoot you cannot redo. Wedding ceremonies, product launches, single-event coverage: tolerance for error here is zero. Using packs of the same model, batch, and cycle count pushes the variables to a minimum. The money saved on a battery is not worth one extra risk.
Cold conditions. Below freezing, usable capacity is already reduced, and two packs on different curves will lose capacity by different amounts, which makes rotation judgments more error-prone. For cold-weather location work, standardize on one model and carry an extra.
Long video takes. Video is a continuous load that demands voltage stability at the tail. If the pack with higher internal resistance happens to be in the camera, it may cut out while the gauge still shows charge, leaving the file incompletely written.
Conversely, for street shooting, travel, and family recording, anything you can redo, mixing is entirely fine and lets you use both packs down. The most common pairing of an LP-E17 T series with an original is the original as primary and the T series as the runtime and recharge fallback, and the T series category covers those scenarios in more detail.
FAQ
Does mixing shorten the original battery’s life?
No. The two packs are electrically independent and there is no path for current to flow between them. The original’s life depends only on its own cycle count, temperature, and storage state.
Can the body tell a third-party battery from an original?
Most bodies read voltage and temperature and therefore work and charge normally. Some omit the genuine-battery notice for non-original packs, or do not show an exact percentage. That does not affect shooting; it just means less information on screen.
Can one charger handle both capacities?
Yes. A dock judges the charging stage by voltage, and capacity only affects how long a full charge takes. With USB-C direct charging the two are entirely independent. Check the markings on both charger and battery for specifics.
With long-term mixing, is periodic calibration needed?
It helps to give each pack a full cycle on its own every few months so the body’s coulomb counter can relearn it. It is not mandatory maintenance, but it keeps the display accurate. More on capacity and fitment is in the capacity and compatibility guide.