--- product_id: 261798251 title: "HXJNLDC DC 3.7V 620mAh 503040 Rechargeable Lithium Polymer Battery for Cozmo ..." brand: "hxjnldc" price: "19700CFA" currency: XOF in_stock: true reviews_count: 13 category: "Hxjnldc" url: https://www.desertcart.sn/products/261798251-hxjnldc-dc-3-7v-620mah-503040-rechargeable-lithium-polymer-battery store_origin: SN region: Senegal --- # 3.7V nominal voltage, 4.2V full charge 620mAh high-capacity power Built-in overcharge & short circuit protection HXJNLDC DC 3.7V 620mAh 503040 Rechargeable Lithium Polymer Battery for Cozmo ... **Brand:** hxjnldc **Price:** 19700CFA **Availability:** ✅ In Stock ## Summary > 🔋 Power up your tech with confidence and style! ## Quick Answers - **What is this?** HXJNLDC DC 3.7V 620mAh 503040 Rechargeable Lithium Polymer Battery for Cozmo ... by hxjnldc - **How much does it cost?** 19700CFA with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.sn](https://www.desertcart.sn/products/261798251-hxjnldc-dc-3-7v-620mah-503040-rechargeable-lithium-polymer-battery) ## Best For - hxjnldc enthusiasts ## Why This Product - Trusted hxjnldc brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Safe & Sound:** Advanced Japanese Seiko IC safeguards against overcharge & short circuits - • **Compact Yet Mighty:** Slim 41×30×5mm size fits seamlessly into your favorite gadgets - • **Power Your Playtime:** 620mAh capacity fuels your Cozmo & smart devices longer - • **Plug & Play Flexibility:** Includes JST 2-pin connector + heat-shrink sleeve for easy custom wiring - • **Fast Recharge, Less Downtime:** Quick charge capability keeps your devices ready for action ## Overview The HXJNLDC 503040 is a rechargeable 3.7V lithium polymer battery with 620mAh capacity, designed for COZMO Vector robots, SkyBell HD WiFi doorbells, FPV watches, and other 3.7-5V devices under 2.3Wh. Featuring built-in overcharge, overcurrent, and short circuit protection via a premium Japanese Seiko IC, it ensures safe, reliable power. Compact and lightweight (13g), it includes a JST 2-pin connector and heat-shrink sleeve for easy installation or custom wiring. Ideal for professionals seeking dependable, long-lasting power solutions for their smart gadgets. ## Description Product description DC 3.7V Model Table of Square Rechargeable Polymer Lithium Battery (applicable to 3.7V-5V electronic products) Please note that connector specifications and polarity are based on the product display image ,the red wire is the positive "+" and the black wire is the negative "-"The yellow (white) lead is a 'thermistor'，Do not reverse-charge or reverse-connectreverse. 3 -wire batteries retain red and black wires, which can replace 2 -wire batteries. Some products' original batteries may lack plugs, have incompatible plugs, or exhibit mismatched polarity. No worries—you can simply cut the wires and use the included heat-shrink tubing to connect the wires of the same color from the old plug. Package: 620mAh LiPo battery x 1 heat shrinkable insulating sleeve x 1 Compatible ： COZMO Vector robot、 SkyBell HD WiFi Video Doorbell、Flysight FPV Watch、 wireless speaker It can also be used for MP3, MP4, MP5, GPS, smart watches, power packs, detectors, More Other 3.7~5V electronic products with power less than 2.29Wh (620mAh). Size: 1.596×1.181×0.196inch (L*W*T) Size: 41×30×5mm (L*W*T) voltage: 3.7V Capacity: 620mAh Weight: 0.458oz（13g) Maximum current: 1A Review: Works Great in Cozmo - Works great in Cozmo toys. Perfect fit. Installation isn't too hard but does require some time and patience. See the picture here of my son's Cozmo torn down to the point where the battery can be replaced. It looks like a lot of pieces but everything disassembles easily and goes back together pretty easy too. The head is a little tricky as there is a small spring that you have to fight as you put it together, but isn't too hard once you figure it out. Sort of like a puzzle. There is a video on YouTube by John that is super helpful. Just watch that once and you'll have it figured out. The hardest part for most people will be just soldering the wires to the circuit board. This battery comes with a JST plug, but you have to cut that off, strip the wires, and then solder them to the board. It's pretty trivial if you know how to solder, but could trip up people who've never used a soldering iron. You'll need to cut the red wire shorter and leave the black wire longer, since the leads come out the same side of the battery, so it's close to the positive tab on the board, but the negative soldering tab is on the other side. Anyway, so far so good. Cozmo is up and running for last few days now with no issues. Haven't timed the battery life, but so far it lasts longer than my son's interest in it for any given moment. Note that it charges quite fast too. So you can play with this thing off and on all day long as long as you park Cozmo on his home charger between plays. Can recommend this battery. And watch John's tutorial too. Happing fixing! Review: Quality Battery - Battery works great! I used it to transform some wired headphones into wireless using a Bluetooth receiver. I cut the connector pin on the end off and soldered the 2 wires onto the board and now I have a better sound experience than you can buy in wireless headphones with a battery that now lasts over a week of 24/7 use between charges! It's been like 2 years so far with zero issue. This battery does have overcharge protection. And if you need to replace the wires, it has convenient solder points. ## Features - Compatible with COZMO Vector robot SkyBell HD WiFi Video Doorbell Flysight FPV Watch wireless speaker Battery replacement。It can also be used in other 3.7-5V electronic products with power less than 2.3Wh (620mAh).（★ Not applicable to high-power electric tools and model aircraft） - Please compare the connector specifications and polarity according to the display diagram before purchasing,★the red wire is the positive "+" and the black wire is the negative "-"，Do not reverse-charge or reverse-connectreverse. ★The primary battery of some products has no plug or mismatched plug or mismatched polarity. It doesn't matter, you can cut and solder the plug directly or use our heat shrinkable insulating sleeve to connect the same color wire. - 503040 rechargeable lithium ion polymer battery, nominal voltage 3.7V, full charge voltage 4.2V, capacity 620mAh, power 2.29Wh, size 5×30×41mm(0.197×1.181×1.598inch）(T*W*L), Weight:13g(0.46oz)，Maximum current:0.6A。 It can prevent overcharge, overdischarge, overcurrent, and short circuit. - It‘s consists of of large-capacity A+ lithium battery, Japanese Seiko IC overcharge and overcurrent short circuit protection board, 3302-26 high temperature resistant silicone cable, and genuine JST Pitch1.25mm 2-pin connector module. - If there are any quality issues within a year, ★please feel free to contact us via email for replacement. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B08PKV564B | | Amperage | 0.6 Amps | | Antenna Location | GPS, Radio, Watch | | Battery Capacity | 620 Milliamp Hours | | Battery Cell Composition | Lithium Polymer | | Battery Cell Type | Lithium Polymer | | Battery Weight | 13 Grams | | Brand | HXJNLDC | | Built-In Media | 620mAh battry x 1 pack, heat shrinkable insulating sleeve x 1 | | Customer Reviews | 4.4 out of 5 stars 1,005 Reviews | | Item Dimensions | 1.61 x 1.18 x 0.2 inches | | Manufacturer | HXJNLDC | | Model Name | 503040 | | Model Number | 503040 | | Number of Batteries | 1 C batteries required. (included) | | Recommended Uses For Product | GPS, Radio, Watch | | Reusability | Rechargeable | | UPC | 054114076826 | | Unit Count | 1.0 Count | | Voltage | 3.7 Volts (DC) | ## Product Details - **Battery Capacity:** 620 Milliamp Hours - **Battery Cell Composition:** Lithium Polymer - **Brand:** HXJNLDC - **Number of Batteries:** 1 C batteries required. (included) - **Recommended Uses For Product:** GPS, Radio, Watch ## Images ![HXJNLDC DC 3.7V 620mAh 503040 Rechargeable Lithium Polymer Battery for Cozmo ... - Image 1](https://m.media-amazon.com/images/I/61q7Lbqex6L.jpg) ![HXJNLDC DC 3.7V 620mAh 503040 Rechargeable Lithium Polymer Battery for Cozmo ... - Image 2](https://m.media-amazon.com/images/I/71qZeb1kqsL.jpg) ![HXJNLDC DC 3.7V 620mAh 503040 Rechargeable Lithium Polymer Battery for Cozmo ... - Image 3](https://m.media-amazon.com/images/I/81jSmvePDIL.jpg) ![HXJNLDC DC 3.7V 620mAh 503040 Rechargeable Lithium Polymer Battery for Cozmo ... - Image 4](https://m.media-amazon.com/images/I/81ygEeonPJL.jpg) ![HXJNLDC DC 3.7V 620mAh 503040 Rechargeable Lithium Polymer Battery for Cozmo ... - Image 5](https://m.media-amazon.com/images/I/616ocrZc8aL.jpg) ## Available Options This product comes in different **Color** options. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Works Great in Cozmo *by D***. on July 24, 2021* Works great in Cozmo toys. Perfect fit. Installation isn't too hard but does require some time and patience. See the picture here of my son's Cozmo torn down to the point where the battery can be replaced. It looks like a lot of pieces but everything disassembles easily and goes back together pretty easy too. The head is a little tricky as there is a small spring that you have to fight as you put it together, but isn't too hard once you figure it out. Sort of like a puzzle. There is a video on YouTube by John that is super helpful. Just watch that once and you'll have it figured out. The hardest part for most people will be just soldering the wires to the circuit board. This battery comes with a JST plug, but you have to cut that off, strip the wires, and then solder them to the board. It's pretty trivial if you know how to solder, but could trip up people who've never used a soldering iron. You'll need to cut the red wire shorter and leave the black wire longer, since the leads come out the same side of the battery, so it's close to the positive tab on the board, but the negative soldering tab is on the other side. Anyway, so far so good. Cozmo is up and running for last few days now with no issues. Haven't timed the battery life, but so far it lasts longer than my son's interest in it for any given moment. Note that it charges quite fast too. So you can play with this thing off and on all day long as long as you park Cozmo on his home charger between plays. Can recommend this battery. And watch John's tutorial too. Happing fixing! ### ⭐⭐⭐⭐⭐ Quality Battery *by M***N on June 24, 2025* Battery works great! I used it to transform some wired headphones into wireless using a Bluetooth receiver. I cut the connector pin on the end off and soldered the 2 wires onto the board and now I have a better sound experience than you can buy in wireless headphones with a battery that now lasts over a week of 24/7 use between charges! It's been like 2 years so far with zero issue. This battery does have overcharge protection. And if you need to replace the wires, it has convenient solder points. ### ⭐⭐⭐⭐⭐ Nice replacement for my Skybell HD V4 *by R***G on August 9, 2022* Bought a house with an expensive Skybell HD V4 Video Doorbell. The thing was working in short bursts, couldn't figure it out. Checked the connections, all was good. Found that the battery on these would expand and die, and that's what happened to mine. I pulled mine apart and found I needed a new battery. I found this replacement on Amazon. Don't do what I did....I threw out the old one before the new one arrived. The plug is not an exact match. You need to splice the wires from the old battery to the new one. The plug is slightly different. Since I didn't have the new one, I improvised. I followed my college engineering training. Step 1: Is it working now? No Step 2: Does the part jam? Yes, the plug doesn't fit cleanly. Step 3: If this battery doesn't work, whats the alternative? Spend $250 for a new doorbell Step 4: Follow the old adage of: If it jams, force it, if it breaks, it needed fixing anyway. I jammed the plug into the socket on the camera using a pair of needle-nose pliers and got it working. The doorbell has been working the last month without issues. I would call this battery a replacement, even if it was a bit more difficult due to me shooting myself in the foot throwing the old one away before I took the plug. ## Frequently Bought Together - HXJNLDC DC 3.7V 620mAh 503040 Rechargeable Lithium Polymer Battery for Cozmo Vector Robot SkyBell HD WiFi Video Doorbell Flysight FPV Watch Wireless Speaker Battery Replacement - PKCELL N Size 1.5V Alkaline Batteries, 10 Pack Ultra Long-Lasting MN9100/E90/LR1 Medical Battery for Medical Devices, GPS Trackers, Flashlights, Key Fobs, 10-Year Shelf Life - Duracell N 1.5V Alkaline Battery, 2 Count Pack, N 1.5 Volt Alkaline Battery, Long-Lasting for Medical Devices, Key Fobs, GPS Trackers, and More --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.sn/products/261798251-hxjnldc-dc-3-7v-620mah-503040-rechargeable-lithium-polymer-battery](https://www.desertcart.sn/products/261798251-hxjnldc-dc-3-7v-620mah-503040-rechargeable-lithium-polymer-battery) --- *Product available on Desertcart Senegal* *Store origin: SN* *Last updated: 2026-07-10*