Short answer: choosing a third-party NB-13L comes down to three things — whether the decoder is complete, whether capacity is stated in Wh and stays within the physical ceiling, and whether the charger controls its bays independently. The decoder decides whether the body shows charge correctly, Wh decides whether the numbers mislead you, and the charger decides how long the pack lasts. Pass all three and a compatible pack is perfectly usable as a primary.
The genuine NB-13L is rated 3.6V, 1250mAh and 4.5Wh. Energy density at this size has a hard ceiling, so anything of the same dimensions claiming 1800mAh, let alone 2000mAh, has either changed cell chemistry — all but impossible in consumer products — or simply written a bigger number. Understanding that filters out most of the marketing.
The first gate: complete decoding
Canon bodies read pack information through the communication contacts to calculate remaining charge and health. Third-party packs fall into three tiers here:
- Full decoding: the body shows a percentage and remaining shots normally, and the original charger recognises and charges the pack. This is the pass mark.
- Partial decoding: the body powers on and shoots, but the gauge is inaccurate — slow at first, then falling to zero abruptly. The original charger may refuse it, leaving you with a third-party charger.
- No decoding: the body reports an unrecognised battery and treats it as unknown. It usually still supplies power, but with no charge information at all.
Partial decoding is the awkward tier because it looks workable. Halfway through a shoot the body says two bars remain when there are only minutes left, and that misjudgement wastes more time than a plain error would. The test is simple: charge fully, then record continuously and watch whether the gauge falls evenly from 100% to shutdown. Uneven steps mean the estimate is being padded.
One further detail: some bodies change how they handle third-party packs after a firmware update. If a pack worked when you bought it and errors after an update, read the release notes before concluding the pack has failed.
The second gate: overstated capacity
| Measure | Genuine | Acceptable third party | Cause for caution |
|---|---|---|---|
| Rated capacity | 1250mAh | 1150-1300mAh | 1500mAh or more |
| Energy | 4.5Wh | 4.1-4.7Wh | mAh only, no Wh stated |
| Charge time | About 2 hours 10 minutes | 2-2.5 hours | “Full” within an hour |
| Weight | About 30g | 28-33g | Noticeably lighter |
| One week at rest, full | Very little loss | Under 5% | More than 20% |
Why look at Wh before mAh? Because mAh is only comparable at the same voltage, whereas Wh reflects energy directly. A 3.6V pack rated 1250mAh is 4.5Wh, and that relationship is fixed. A maker who lists mAh but not Wh usually does not want you doing the arithmetic.
Weight is an underrated indicator. Cell energy density sets a lower bound on weight for a given volume, so a pack claiming far more capacity while weighing less is almost certainly overrated. Without a precision scale, comparing it by hand against an original is enough to feel the difference.
Charge time is the third check. A 1250mAh pack charged at 0.7A should take close to two hours. If a pack reports full in half an hour, either its capacity is far below the claim or the charger’s cut-off detection is faulty — neither is desirable.
The third gate: the charger
The genuine CB-2LHT outputs 4.2V / 0.7A in a single bay and fills a pack in about 2 hours 10 minutes. Its real value is not speed but cut-off accuracy: 4.2V is the charging ceiling for this cell, and going past it accelerates ageing.
The common failing in third-party chargers is paralleled bays. A unit advertised as three-bay may feed all three from one output, so whichever pack fills first keeps receiving a trickle and swells first over time. Check whether the manual mentions independent control or independent channels, and whether each bay has its own indicator. Put three packs in and the lights should change individually, not in unison.
A USB charger is the other option. It is small, runs straight off a power bank and suits travel. The drawback is an output usually around 0.5A, so a full charge takes two and a half hours or more, and protocol compatibility with power banks varies. Fine as a backup; judge it on real behaviour before making it primary.
If you also use other Canon bodies, keep chargers separate. The NB-13L is a 4.2V single cell, the LP-E17 is 8.4V with two cells, and the LP-E6 is also 8.4V but at a different current. Similar-looking connectors do not mean interchangeable, and the wrong pairing can damage the cell outright.
Cells and protection boards: invisible, but they decide lifespan
At the same 1250mAh, cell quality determines how much capacity remains after 300 cycles. A properly built pack uses cells from a reputable supplier and typically holds above 80% after 300 cycles; poor cells can fade visibly within 100, which shows up as a pack that gets less useful the more you use it.
The protection board handles overcharge, over-discharge, overcurrent and short circuit. It is invisible until the day it matters. How to judge: a good product has even seams, clear capacity and voltage printing, and gold- or nickel-plated contacts, while a poor one has burred mouldings, blurred printing and plain brass contacts that blacken after a few insertions.
On price, an acceptable third-party NB-13L usually costs about half the original, and anything cheaper invites the question of where the cost was cut. The unit price in this class is low to begin with, so gambling on a cell that may swell to save a small amount is a poor trade.
The buying logic for small packs of this kind is universal: Sony’s NP-FW50 system is judged on the same three dimensions — decoding, Wh and charger. Learn it once and it carries over to whatever body you buy next.
FAQ
Will the camera treat a third-party pack as counterfeit?
Not if it decodes fully. The body only reads information; it does not judge brands, and correct communication is all that is needed for the gauge to work. A “cannot recognise” message means the decoder is missing or has failed, regardless of brand.
Is an NB-13L rated 1800mAh worth buying?
Not advisable. Energy density at this size has a physical ceiling, and 1800mAh is close to 1.5 times the original, which is not achievable without a change in volume. Such products are either overrated or built on very short-lived cheap cells.
Can the original charger charge a third-party pack?
A fully decoding one, yes; a partially or non-decoding one may be refused. Refusal is not a fault but the charger’s protective response when it cannot read the pack. Use a third-party charger in that case, and confirm its cut-off voltage is 4.2V.
How long will a third-party pack last?
At two or three charge cycles a week, a properly built pack starts to fade noticeably after about two years, showing as shorter runtime and faster drain. Retire it immediately if it swells. Storing at around half charge and avoiding heat adds considerably to its life. More maintenance detail is in the NB-13L section.