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I recently found this lithium polymer battery which claims to be 12.6V, 10Ah:

http://battery.com.sg/un_product_details.asp?pid=4252

for S$ 67.

For reference, a single 18650, 3400 mAh cell costs between S$ 12 and 20 in Singapore. For the same capacity and voltage, a battery made of 18650s (3S3P) which means that this battery is way cheaper than it should be.

The seller claims that it is protected, too. I know that Li-Po has great energy density, but is this too good to be true?

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closed as primarily opinion-based by uint128_t, Dmitry Grigoryev, pipe, ThreePhaseEel, Enric Blanco Apr 29 '17 at 6:03

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. If this question can be reworded to fit the rules in the help center, please edit the question.

  • \$\begingroup\$ Can you link to the datasheet instead of a picture? \$\endgroup\$ – Christian Apr 13 '17 at 8:52
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    \$\begingroup\$ Take any of the reputable manufacturers. Check if its above their best battries. If yes, then its fake. \$\endgroup\$ – PlasmaHH Apr 13 '17 at 8:54
  • \$\begingroup\$ If it's not above, it doesn't mean it's accurate too (it still could be less). So, unless it is from a reputable source, you can't really trust it. \$\endgroup\$ – Wesley Lee Apr 13 '17 at 9:20
  • \$\begingroup\$ Looks POTENTIALLY OK. Website and products offered LOOKS legit. Various voltages appear legit. It's hardly a 13V battery in normal use of course. 12.6V fully charged but rapidly falls below that. Mean voltage across discharge range about 10.8V. They say 7.2V end of discharge but I'd strongly recommend 9V min for longer cycle life. Minimal capacity loss. || This Alibaba 12V 10Ah LiIon battery is too suspect to be safe but looks very similar and MAY cost $US21 in 100 quantity. ($ on ad often wrong). \$\endgroup\$ – Russell McMahon Apr 13 '17 at 12:31
  • \$\begingroup\$ It seems to be plausible i guess, so short of opening the thing up there isn't a way to verify. Thanks all for your help! \$\endgroup\$ – Jayce Cheng Apr 15 '17 at 6:28
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a single 18650, 3400 mAh cell costs between S$ 12 and 20 in Singapore

That's way overpriced, even if you are talking about prices in Singapore dollars. Panasonic doesn't sell cells directly to consumers, but an indication of their true value is that you can easily find e.g. 3.4 Ah ncr18650b cells from shops for vaping and flashlight enthusiasts for about 5 (US) dollars a piece, with battery manufacturers paying even less as they source the cells in bulk directly from the manufacturer. A 3s3p pack of them would cost about 45 dollars, plus the price of the case, labour and protection and balancing circuitry.

Radio control hobby shops also sell cheap high discharge rate batteries to consumers. For example, you can buy a 3s 2200 mAh 20C pack for 10 dollars, 5 of which in parallel would yield a 3s5p 11 Ah $50 pack.

I'd say it's quite probable that that pack is legitimate. However, there are many scammers in the world that count on you not having a charge counting charger. Beware of anything suspiciously cheap, or with "fire" in the brand name, you can bet that they lie about the specs.

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  • \$\begingroup\$ Oi!!! " ... or with 'fire' in the brand name" is my line :-) :-) :-) \$\endgroup\$ – Russell McMahon Apr 13 '17 at 12:01
  • \$\begingroup\$ Thanks jms! I visited 4 stores around Singapore and it seems like cells here are just super overpriced. It may be because of strict import controls sadly. I'll give hobbyking a go! \$\endgroup\$ – Jayce Cheng Apr 15 '17 at 6:26
  • \$\begingroup\$ lol yes, one shop was trying to push a 8000 mAh ultrafire cell. \$\endgroup\$ – Jayce Cheng Apr 15 '17 at 6:27

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