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Polymer Lithium Ion Battery - 400mAh

This is a very small, extremely light weight battery based on the new Polymer Lithium Ion chemistry. This is the highest energy density currently in production. Each cells outputs a nominal 3.7V at 400mAh! Comes terminated with a standard 2-pin JST-PH connector - 2mm spacing between pins. These batteries require special charging. Do not attempt to charge these with anything but a specialized Lithium Polymer charger.

Battery includes built-in protection against over voltage, over current, and minimum voltage. Please use caution when using this battery in wearable projects. When using conductive thread, a short in the thread can create sparks and heat. We recommend using coin cell batteries for beginners.

Note: Due to the requirements of shipping these batteries, orders may take longer to process and therefore do not qualify for same-day shipping. Additionally, these batteries can not be shipped via Ground or Economy methods to Alaska or Hawaii. Sorry for any inconvenience this may cause.

Note: Be careful with the JST connectors. They can stick in pretty good and tugging on them can damage the connector. Check this tutorial for an easy way to remove them safely.

Note: This item is non-returnable. If this item arrives damaged or is not functioning properly, please do not hesitate to contact us to see if further actions may be taken.


Weight: 9g


2C continuous discharge - very high for low price Excellent long-term self-discharge rates (<8% per month) Robust power source under extreme conditions (-25 to 60C)


[Datasheet](http://cdn.sparkfun.com/datasheets/Prototyping/PRT-10718 GSP652535.pdf) (LiPo Cell) Datasheet (Protection Circuit) JST connector [MSDS](http://cdn.sparkfun.com/datasheets/Prototyping/Lithium Ion Battery MSDS.pdf)

* * 5 x 25 x 35mm

  • [Datasheet](http://cdn.sparkfun.com/datasheets/Prototyping/PRT-10718 GSP652535.pdf) (LiPo Cell)
  • Datasheet (Protection Circuit)
  • JST connector
  • [MSDS](http://cdn.sparkfun.com/datasheets/Prototyping/Lithium Ion Battery MSDS.pdf)

Polymer Lithium Ion Battery - 400mAh Product Help and Resources

Core Skill: Electrical Prototyping

If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.

1 Electrical Prototyping

Skill Level: Noob - You don't need to reference a datasheet, but you will need to know basic power requirements.
See all skill levels


Looking for answers to technical questions?

We welcome your comments and suggestions below. However, if you are looking for solutions to technical questions please see our Technical Assistance page.

  • Member #48425 / about 11 years ago / 3

    Hello, in the datasheet it seems that the discharge rate is 0.2C, not 2C, could you check it out?

  • dtderry / about 10 years ago / 2

    Are these and the other capacities LiPo's going to be in stock soon?

  • bobdabiulder / about 7 years ago / 1

    So, this says, "Each cell outputs a nominal 3.7V at 400mAh!" So the rating is 3.7v @ .4amps, but how many (milli)amp-hours is it?

  • I'm slightly confused about the specs for these batteries. As already mentioned the 2C discharge rate is not mentioned in the datasheet (the datasheet does mention 0.2C as a "typical" discharge rate in tests, but I couldn't find any mention of a maximum discharge rate at all). Also, for the charge rate, the datasheet says that "fast charge" can happen at 1C, but then the remarks say "250mA". AFAIU, 1C would mean 400mA (or perhaps 450mA, as the datasheet mentions 400mAh as the minimum capacity and 450mAh as the typical capacity).

    So, any additional information about this?

  • darudude / about 7 years ago / 1

    Have these batteries gone through IEC62133 certification for sale in North America?

  • LED addict / about 9 years ago / 1

    Can I wire these in series? I don't want to charge them in series, just discharge them. I thought you could but then I read a comment that made me think you can't.

    • Kamiquasi / about 9 years ago / 1

      You can.. you just don't want them to be too dissimilar ( and of course don't charge them in series - I know you said it, just repeating it for those who need to read it twice ;) ) Which comment are you referring to?

      • LED addict / about 9 years ago / 1

        Thanks. It's farther down in this feed, by RobertC.

        • Kamiquasi / about 9 years ago / 1

          Seems like Robert isn't too convinced that these specific batteries will be consistent in makeup - i.e. they may actually be too dissimilar. I'd take his advice in that case :)

          • LED addict / about 9 years ago / 1

            Aww... I was so hopeful... But since I'm back to the drawing board, do you have any idea how I should go about getting 8-9ish volts out of LiPo batteries?

            • Kamiquasi / about 9 years ago / 1

              I'd say either find LiPos that are already set up in series (3S: 11.1V - step down, 2S: 7.4V - step up .. you'll want a balancing charger, of course) so that you know they should be good in that configuration - or boost from a single cell's 3.7V up to the voltage you desire. I don't think there's any off-the-shelf product for that boost (didn't google much), but you should be able to find a chip and/or circuit that'll do it if you're willing to build it yourself.

              Alternatively, there's things like 9V Li-ion Rechargeable Battery - 350mAh though a comment there suggests it's actually just 7.2V, or you could go for a NiMH solution (example link only!) which readily come in 8.4V packs of various sizes and appropriate chargers.

  • Member #130735 / about 9 years ago / 1

    Can someone please confirm the pinout of the connector. I assume pin1 is +, pin2 is -

  • steven6282 / about 10 years ago / 1

    Hmm, wow. I was thinking about using one of these in a small outside project with a small solar cell for charging but I just read the datasheet and it appears the operating temperature while charging is 0 to 45c. So I can't charge it if it's below freezing or over 113 degrees f... kind of ruins that plan then. It gets below freezing where I live frequently in the winter, and in the summer 113 inside of a sealed container in direct sunlight is very possible....

  • Red / about 10 years ago / 1

    Sparkfun without any LiPo battery ?? How is it possible ??

  • Member #9023 / about 10 years ago / 1

    Note that the JST connector link links to a 'PH' series connector with 2.0mm pitch. The battery spec says it has a 'ZH' series connector with 1.5mm pitch. Jay.

    • MikeGrusin / about 10 years ago / 1

      We have these custom-manufactured with the 2mm connector. Sorry for the confusion!

  • Member #228081 / about 11 years ago / 1

    I am looking to do a portable project that uses EL and im wondering if this can power it? does anybody know? or is there a better way of powering the inverter? http://www.sparkfun.com/products/10201

  • LexanPanda / about 11 years ago / 1

    Battery includes built-in protection against over voltage, over current, and minimum voltage.

    Does this mean it will stop supplying power before draining completely?

    • MikeGrusin / about 11 years ago / 1

      Yes, but a) draining a Lipo completely will permanently damage it (this circuitry prevents that), and b) by the time it cuts off, you're already at the point on the discharge curve where it's falling very rapidly - you've already used 95% or more of the battery's capacity.

  • Member #167356 / about 11 years ago / 1

    Any idea when this will be back in stock?

  • Member #143086 / about 11 years ago / 1

    If I need to run 5V on my Arduino, can I hook 2 of these batteries in series? If so, can will I need a special charger for charging the batteries when connected in series?

    • Check out the LiPo booster. You wouldn't be able to charge them in series, and they will most likely drain unevenly and get damaged if you hooked them up in series.

  • Nathan, Thanks for listening to my request (probably many, too)! :)

  • MrTangent / about 11 years ago / 1

    What is "2C continuous discharge"? A coulomb is one amp for one second. I could understand discharging continuously at a certain number of amps.

    • C * AH = discharge rate. So, in this case it is 2 * 400 = 800mA.

      • MrTangent / about 11 years ago / 2

        Aha, thanks, I get it now...I was never going to figure it out while thinking that C stands for coulombs here. Reading about C-rate helped.

  • Member #585 / about 11 years ago / 1

    This is precisely what I've been waiting for. It does appear to be a bit more thick than the other batteries though.

Customer Reviews

4.5 out of 5

Based on 19 ratings:

Currently viewing all customer reviews.

1 of 1 found this helpful:

Grabbed one of these to run ESP8266 project

It's a power-hungry little chip (WiFi with SOC) and this powered it nicely for over 6 hours. They are right about the JST connectors, thay can be tricky.

Great battery with small issues

Very easy to use, compact and light, but a few issues. Used these batteries with young middle schoolers, and had a few batteries get their wires pulled out. Not sure if it was the kids being too rough or a bad batch, but tell your kids to be gentle and they work great.

Great product, even better customer service.

Long lasting, easy to recharge.


If you have bought any of these LiPo batteries you have seen them all but the 400mah fits for me in a ideal compromise on dimensions. These packs are well built, nothing feeling cheap or dangerous. Generous wire lead length.

Ploymer Lithium Ion Battery

purchased for an Engineering student for "Tech Wearable" competition. They were pleased with the performance. Sparkfun prices and items are fantastic- you receive an instant invoice and follow-up emails regarding your purchase. Thanks.

Took a hard fall

and kept on working just fine. Charged quickly, powered a 16 LED array all night before taking a hard hit to the pavement. Everything stayed in tact and kept on working!


I have used these with the power cell and they work great. Thanks. I am using them for high powered LEDs. I was wondering if I could pack two of them together for double the power in a very small place I am working with? I ordered the crimpers and JST plugs to do that myself but was wondering if Sparkplug could do that for me?

I'm sorry, but we don't make these in house, so we can't offer custom wire configuration. Happy hacking!

A Quality Cell With Protection Module

I have ordered these cells for a few months. I have found them to be of high quality. All test at the correct capacity. These are so much better than anything the radio control manufacturers sell. These are not for high drain applications. The protection control modules is a very important feature that gives piece of mind. The most important feature of the PCM is keeping the cell from discharging to a very low voltage. To low voltage WILL damage Lithium Polymer cells. I will be buying more of these cells.

Wish they'd offer

Love these Lipos! They preform to their specifications. I really wish they'd offer these without the protection board in them. I am forced to remove these protection circuits for my application.

works as expected

Fine source of 3.7V.

I purchaed these for a remote control and they have worked well so far.

Works as expected

Replaced the battery on my Dashcam with this one. It works as expected..


I mounted it in my Sena bluetooth interphone and it's perfect. Great quality!

Excelent product.

It works very well

I was able to combined them into 7.4 v batteries. I would like some around 200 that were about at least a third smaller. I model 1880 V&T and the tenders are really small.

Good Battery

I have an arduino mkr1000, which l got this Lipo battery for. I initially had trouble removing it but after reading the jst tutorial I understood how to get it out. The 3.7v Lipo I bought is perfect for my projects.

Works good.

Seems to power my little Adafruit board and OLED display.

Small but strong

A lot of mAhs for such a small battery!

Just the size we needed

We installed these in our prototype LED ring light assembly and they worked out well for the application.