# Inline Fuse/Surge Protector for Battery powered TX2 **URL:** \ **Category:** Jetson TX2\ **Created:** [August 27, 2017, 2:03pm UTC](https://forums.developer.nvidia.com/t/inline-fuse-surge-protector-for-battery-powered-tx2/52917 "2017-08-27T14:03:52Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![christopheraburns](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@christopheraburns](https://forums.developer.nvidia.com/u/christopheraburns)\ **Post date:** [August 27, 2017, 2:03pm UTC](https://forums.developer.nvidia.com/t/inline-fuse-surge-protector-for-battery-powered-tx2/52917/1 "2017-08-27T14:03:52Z")
I am going to build a project with a battery powered TX2 (need to cut the cord). I am looking for recommendations on an inline fuse system. Is it necessary? I am assuming it’s not possible for a battery to surge but I want to add a means to charge the battery from the wall when the project is not in use and should install sometime of protection. Anyone else build something similar? Thanks, Chris ---
**Author:** ![snarky](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/snarky/32/10446_2.png) [@snarky](https://forums.developer.nvidia.com/u/snarky)\ **Post date:** [August 28, 2017, 12:17am UTC](https://forums.developer.nvidia.com/t/inline-fuse-surge-protector-for-battery-powered-tx2/52917/2 "2017-08-28T00:17:06Z")
A fuse is always a good idea, of some sort. A 2-3A PTC resettable fuse might be just the ticket for this app (unless it needs to be in very warm places): > **[0ZCF0200AF2C | Digi-Key Electronics](https://www.digikey.com/en/products/detail/bel-fuse-inc/0ZCF0200AF2C/4156183)** > > Order today, ships today. 0ZCF0200AF2C – Polymeric PTC Resettable Fuse 24V 2 A Ih Surface Mount 2920 (7351 Metric), Concave from Bel Fuse Inc.. Pricing and Availability on millions of electronic components from Digi-Key Electronics. > **[MF-R300 | Digi-Key Electronics](https://www.digikey.com/en/products/detail/bourns-inc/MF-R300/259975)** > > Order today, ships today. MF-R300 – Polymeric PTC Resettable Fuse 30V 3 A Ih Through Hole Radial, Disc from Bourns Inc.. Pricing and Availability on millions of electronic components from Digi-Key Electronics. > **[MF-S200 | Digi-Key Electronics](https://www.digikey.com/en/products/detail/bourns-inc/MF-S200/3193310)** > > Order today, ships today. MF-S200 – Polymeric PTC Resettable Fuse 30V 2 A Ih User Defined Strap from Bourns Inc.. Pricing and Availability on millions of electronic components from Digi-Key Electronics. For batteries, you’ll be looking at a 3S LiPo (“11.1V”), a 4S LiFePO4 (LFP) (“12.8V”) or a 4S LiPo (“14.8V”) battery. Note that the batteries are higher voltage when charged, and lower voltage when discharged, but the Jetson voltage regulators and carrier board circuitry should be able to deal with that. Note that Lithium batteries do not like over-charging, and do not like over-discharging, so you need some kind of battery safety / charge control. Some batteries can be bought with “protection PCB” built in, which sometimes does this correctly for you. Othertimes, you need to design that circuitry yourself. How heavy are you willing to go? How long does it need to run? A car battery and car battery charger may be all you need :-) Main problem is making sure that you don’t over-discharge the batteries and kill them, because LiPos REALLY don’t like being discharged below 2.5V per cell – either they become worse batteries that get warmer under load and last shorter, or they just stop taking a charge after this happens. I use custom circuitry to do this protection; you may get it from battery pack protection PCBs depending on what batteries you buy. A 3000 mAh Lithium battery pack like this can run a Jetson for about 3 hours on heavy load, or longer on lighter load: > **[AT: Tenergy Li-PO 11.1V 3000mAh Rechargeable Battery Pack w/ PCB (3S1P,...](https://power.tenergy.com/AT-11.1-3000mAh-LIPO-31203/)** > > Tenergy POWER, is our online store for TENERGY that brings our products and the same support directly to customers. Whether you just need basic rechargeable batteries for your HOME, business, school, or projects we're here to help! That battery is nice because it has built-in protection circuitry. Perhaps this charger will work with it: > **[Tenergy 11.1V (3S) Li-ion/LiPo Battery Pack Smart Charger (Output: 12.6V, 2A)](https://power.tenergy.com/tenergy-11-1v-3s-li-ion-lipo-battery-pack-smart-charger-output-12-6v-2a/)** > > Buy Tenergy Smart Charger for 11.1V Li-ion/LIPO Battery Pack for Constant Charge rate. Easy to operate. ---
**Author:** ![nadeemm](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/nadeemm/32/367020_2.png) [@nadeemm](https://forums.developer.nvidia.com/u/nadeemm)\ **Post date:** [October 18, 2021, 6:26pm UTC](https://forums.developer.nvidia.com/t/inline-fuse-surge-protector-for-battery-powered-tx2/52917/3 "2021-10-18T18:26:50Z")