Very embarrassed to ask, but I need some education. Electric Logic: My understanding is a device will only pull the current (Amps) needed to operate it. i.e. say you plug in a tyre pressure pump and it says its rated at 3 Amps. Just because the cigar lighter socket is rated, and I guess fused at 15A. Your tyre pump would only draw 3A. Maximum. Q1. Is the above correct? If hopefully yes, Q2. does the same apply to “USB chargers”? Requirement: My dashcam says one must use the supplied Cigar Plug lead, that plug thing converts the 12V cigar socket (rated at max 15A) into 5V and 1A (sadly on a moulded cable terminating in a USB Micro B male, which you insert into the dashcam. I need to find an External Battery Pack to power the dash cam in “Parking mode”. I.e. once the ign. Powers down. Ideally I would like a power pack, that had a 12V 2A female cigar socket output. But I cant find one with a LiFePO4 battery in it (safer than Lithium Ion batteries). I have however found a near perfect substitute, other than it only has two USB type A output sockets rated at 3.1A each. But No female 12V cigar socket. My thoughts are:- Get a Cigar plug charger with a 5V 1A output, and buy a USB type A to USB type Micro B. To run the dashcam when I am driving. I.e. powered by the car socket ... no issues there. I could then pull the USB type A end out of the cigar plug charger , and insert it into one of the battery pack’s USB Type A output sockets (rated at max 3.1A). My concern is ... unlike most simple electric circuits, where the dashcam would only draw up to 1A, because that is what it is rated at; would the battery-pack “charger”, (because essentially that is what it is .. a charger) force out 3.1A and essentially send too many amps into the dashcam and either burn it out, or blow an internal fuse in the dash-cam? Or Would the dash-cam just take 1A? My fear is based on the minimal experience of Apple chargers. Namely the iPhone 6 plus came with a 5V 1A charger, and the iPad Air came with a 5V 2.1A charger. If you accidentally charge the iPhone with the iPad Air’s charger ... it takes about half the time! Ergo I assume its sending 2.1A into the phone not the prescibed 1A. And the Apple salesman, did say it was not a clever thing to do .. as it would shorten the iPhone’s battery’s life expectancy. My other concern is when one reads that it has “intelligent circuitry to maximise the charge” and names a few devices like an iphone or samsung. What happens when it doesnt know what the device is ? Does it force the maximum current out? A quick education in basic electrics would be much appreciated. As I would hate to fry my new dash-cam LOL Proposed external battery / charger Tqka 20000 mAh portable charger £19 at Amazon Tqka 20000mAh Portable Charger, 3.1A Dual USB Output Smart Charge External Battery, Ultra High Capacity Power Bank with LED Digital Display for iPhone, iPad, Samsung and More - Black https://www.amazon.co.uk/dp/B073QQPKVY/ref=cm_sw_r_cp_tai_HZRwAb6Y5PVGF Of course the official option is to buy a Cellinc Neo for £200! And thats only rated at 6000mA! ... not good value.