EEMB Lithium Polymer Battery 3.7V 1400mAh 112945 Lipo Rechargeable Battery Pack with Wire JST Connector for Speaker and Wireless Device- Confirm Device & Connector Polarity Before Purchase

I use these to build head lights into head-mounted magnifiers which I use a lot. One of these, a miniature spst switch and one or two 3-4v 150ma cob led’s gives me the extra light I need. These are light weight and have been reliable so far. I charge them with cheap USB lipo chargers which deliver about 350ma.

My very handy shirt pocket oscilloscope had an unusual battery size, but when my battery failed, the seller did not have a replacement. The Amazon sourced battery I bought isn't the exact shape as the OEM, but the new one fits fine, has the same current capacity and operates exactly the same as the old battery (when it worked). The new battery has completely restored the operation of my scope, charging and discharging as before. The new battery did not have the same connector as the old, but it was an easy task to cut off the two connectors and swap them. Having a battery that fits is a whole lot cheaper than buying a new scope. I really like the many different sizes and shapes offered by Amazon.

As noted in the product title, beware of the polarity. For some reason, there are two common wiring conventions. Since I've been using a lot of Adafruit boards lately, I needed it wired for "center negative." I tested it right after it arrived and quickly reversed the polarity. No soldering needed — just a male and female JST cable and some solderless connectors like Wagos. Moral of the story: always check polarity before plugging in a LiPo! Once rewired, it charged and worked perfectly with my dev boards.

This battery works great for powering speakers and other small wireless gadgets that take a 3.7 V Lipo with a JST connector. It fits neatly into compact builds and holds a reliable 1200 mAh charge through several cycles. The JST pigtail connector felt snug and didn’t wiggle loose even when I was moving things around. Setup was easy as long as you double check the polarity before plugging anything in — the warning in the listing is fair. My only small issue is that the battery doesn’t come with any mounting tape or foam pads, so you’ll need to improvise some cushioning in your enclosure if you want it snug. Other than that it’s performed consistently without swelling or dropouts. Great value if you need a lightweight LiPo pack for DIY projects. I’d give it four stars because of the lack of built‑in mounting aid but otherwise very solid.

I replaced the battery on my Sedici Bluetooth helmet. The battery is the same size, but the connector did not work. I had to splice the wires in with butt connectors. So happy to have a bluetooth that last more than 20 minutes.

Multimeter reading zero volts across the cell fresh out of the box. Something either shorted or severed connection. Or it died in storage, left uncharged and alone for years in a forgotten corner of some hot warehouse -- it's lifeless corpse delivered to my doorstep for a pittance.

I bought this to replace the battery in a BEM mini speaker. I did have to remove the connector to solder directly to the board inside but it's been working like new again. I ran the speaker for several hours after a full charge and it still had pretty of juice left. I would buy this again

CHECK POLARITY, CHECK THAT THE RED CABLE GOES TO THE POSITIVE ON WHATEVER YOU CONNECT IT, IF IT DOESN'T YOU CAN FRY YOUR ELECTRONIC OR BATTERY MAY CATCH FIRE will update after I charge and see how well it holds charge

Good item

Der Akku kam schnell und sicher Verpackt bei mir an. Ich habe ihn als Ersatz bestell, da bei einem Gerät der orginalakku sehr minderwertig war und die Lötstellen sehr unsauber waren, und er sich wahrscheinlich deswegen so schnell selbst entladen hat. Der neue Akku ist sehr gut verarbeitet und hat saubere Lötstellen. Das Gerät funktioniert nun wie es soll.

Worked in our Vektor. Easy to install.

Ottima qualità, come da adescrizione.

Der Akku macht einen hochwertigen Eindruck und liefert eine stabile Spannung. Ich verwende ihn für kleinere Elektronik- und DIY-Projekte, wo kompakte Abmessungen wichtig sind. Die Kapazität entspricht den Angaben und der Akku lässt sich problemlos integrieren. Verarbeitung und Anschluss wirken solide. Fazit: Ein zuverlässiger Akku für Bastler, Maker und Elektronikprojekte.