Author Topic: LiIon battery certifications  (Read 1282 times)

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Offline 5upercircuitsTopic starter

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LiIon battery certifications
« on: March 19, 2018, 11:50:02 am »
Hey guys :),

I'm making an audio recorder device that will be powered by a LiIon battery from Varta Microbatteries (Type 1/LPP 523450 S PCM W). What certifications are needed to sell such a device internationally specifically for the battery?
So far I've read about the standards:
- UN38.3 - Seems like this is mostly needed to be allowed to transport batteries i.e battery manufacturer will anyway have to do this
- UL1642 - Seems to be the world wide standard and is applied to most batteries
- IEC 62133 - Seems to me like an addition for more safety in case it's needed (maybe medical, aerospace?), however, I don't think that this is needed for general consumer devices

Is my assumption correct that I should be fine if the battery has a UN38.3 and IEC62133 certificate? Of course I don't expect legal quality advice  ;), just tell me what you think and your experiences  :)

Link about certifications:
- http://www.metlabs.com/battery/top-3-standards-for-lithium-battery-safety-testing/

Link for battery:
- https://www.varta-storage.com/wp-content/uploads/2017/08/CellPac-Lite-all-Product-Information-Sheets.pdf
- https://www.varta-storage.com/wp-content/uploads/2017/08/CellPac-LITE-Technical-Handbook.pdf
 

Offline SiliconWizard

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Re: LiIon battery certifications
« Reply #1 on: March 19, 2018, 03:10:25 pm »
Hi,

for portable devices of this kind, the UL1642 compliance is recognized pretty much everywhere in the world, so that's enough for the safety of the battery itself if you're not selling the battery separately.
As a side note, you can't go wrong with VARTA batteries. :-+
So, as far as the battery is concerned, you've made a sound choice.

That said, you probably know that selling electronic devices entails a certification of some kind (depending on the countries) for the whole device and not just for the battery. In the EU, the CE mark is mandatory for this class of devices, but it can be self-marked by the manufacturer. You have to ensure that you comply to the essential requirements of the appropriate directive(s). The CE mark is recognized in some countries outside of EU, but it may not be enough. China, Japan, the USA have specific certification requirements and the CE mark won't work for those markets. And there are a lot of other specific cases...

Electrical safety requirements will not only involve the battery itself but also the way it's integrated in your product and the added protection measures you have taken. Having a certified battery won't be sufficient to make your device safe as whole.
 
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Offline 5upercircuitsTopic starter

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Re: LiIon battery certifications
« Reply #2 on: March 19, 2018, 05:19:30 pm »
Thank you very much for your answer  :). I also found that Varta looks like a pretty good quality battery. I don't want to save money on the battery and then have customers with burnt body parts  :scared:

Regarding certification in general. Yeah I know that I have to comply to CE, FCC, etc. I used a bluetooth module NINA-B112 from u-blox which is precertified in terms of radiation etc, but I'll still have to comply to the rest (e.g. EMC tests). Those test are not cheap at all, so if the project goes well then I'll do a crowdfunding and see if people are interested in the idea.

Regarding electrical safety. It's a low power product but still, it has a LiIon battery built inside. Not accessible to the user though. In terms of safety, I added a battery protection chip AP9101CAK6-CATRG1 by Diodes. I have mostly worked in railway before this, so I'm not really familiar with consumer standards and also railway doesn't really use LiIon batteries  ;)

Do you think the AP9101CAK6-CATRG1 will be enough to call it safe or do I need to do something more serious? I also think the mosfet to separate the battery from the rest of the circuit will be crucial so I used a fairly strong 11A double N-mosfet with 60A peak (ECH8695R-TL-W)
 

Offline SiliconWizard

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Re: LiIon battery certifications
« Reply #3 on: March 19, 2018, 07:27:06 pm »
This Varta battery already contains an electronic protection circuit (usually called PCM), so using an external IC (such as the AP9101C series) doing the same job (as far as I gathered) adds no value IMO. (Cascading such circuits may even confuse the PCM inside the battery itself in some cases.)

Safety issues will mostly be related to your circuit itself. This battery can provide a generous amount of current, so you probably want to add some kind of fuse, PTC or hard current limiter between the battery and your electronics, just in case your circuit goes wild. Your circuit may overheat in case of a short-circuit well before it's unsafe for the battery and its PCM kicks in. This battery also contains an NTC so ideally you should choose a charger IC that can monitor the NTC (there are quite a few) to avoid excessive battery heating. The charger IC will be part of the safety of your device, so choose it carefully.

You also have to provide some room around the battery in your enclosure to allow for some expansion. Li-ion batteries will inflate during their lifetime and they don't like being compressed. The amount of typical worst case expansion is usually provided by the battery manufacturer.

 
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Offline SiliconWizard

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Re: LiIon battery certifications
« Reply #4 on: March 19, 2018, 07:55:35 pm »
By the way - Additionally, since you're going to use a radio module, you'll have to comply with the associated requirements even if the module has been pre-approved. A radio solution can only be "certified" in its nominal environment, thus your product. In the EU, it's the RED, which is a bitch.

Some starting points:
https://library.ul.com/wp-content/uploads/sites/40/2015/02/UL_WP_Draft_EU-Approval-of-Host-Devices-with-Integrated-Wireless-Modules_v6.pdf
http://www.elitetest.com/sites/default/files/downloads/ce_mark_low_power_transmitters_june_2016_6-17_keh.pdf

Hopefully you're not discouraged yet.   ^-^
As you mentioned, this will really matter only when you're thinking of going commercial, but just know that they can take a substantial amount of time and money.
 
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Offline 5upercircuitsTopic starter

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Re: LiIon battery certifications
« Reply #5 on: March 19, 2018, 09:49:39 pm »
Thank you very much for your detailed answer :)
Yeah, I saw that it also has the same protection included, I just felt kinda unsafe to only rely on the internal protection lol  :P, so I added the chip. What you said makes 100% sense though.

I do plan to add fuses to both the battery and a USB connector for charging. The charger is from TI BQ24040DSQR and comes with overvoltage protection, safety timer, short circuit protection, current limitiation, thermal regulation, NTC, so it's at least not some unknown brand, safety comes first in this matter.

I knew that my device will have to comply to RED. However, I assumed I'd only have to worry about stuff not related to the bluetooth module. Guess, I was a little too optimistic  |O

haha, don't worry I'm not discouraged at all. I know it's hard and I build the whole project in public so everybody can watch me doing it (on Twitch). The goal is to do a crowdfunding at the end, but if it doesn't work out then I'll just move on with my next idea. The crowdfunding is just for market verification so that I don't end up with a couple certification stickers, 20k gone and no customers  :-DD

Thank you very much for your answers and also the awesome links :)
 


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