Ba#eries for Mobile and Emergency Power DV Hotspots Rick Frerker January 2017
So,.You got your DV Hotspot working all nice and cozy in your shack. But Now What? You want to use it in your car Oh Really? You want to use it in your back pack Seriously? You want to use it during a power outage. Are You Kidding me? Going Mobile, Portable or Backup Power You are going to need a USB ba#ery Pack!
BUT, So Many Ba#ery Choices How do I know which one best fits my needs? Define realisxc requirements What are the safety consideraxons? Exposure to 60 0 C, esp while charging/discharging Cheap Cells Why not just use the USB plug in my car? Charge Rate LimitaXons Car ba#ery drain Are Bargain Basement Ba#eries just as Good? Yes, if you don t mind the risk of catastrophic failure.
What you need to know: Capacity: How long between charges? How many devices need to be powered? What s the current drain? Environmental Exposure: Will the ba#ery stay in the vehicle (during the heat of the day)? Ba#ery placement in the car? (Avoid Dash and Direct Exposure to Sun) How Cold will it get? Will the devices remained powered while the car is parked? Func<onality: Do I need the ba#ery to be charged while driving? How fast do I want to charge the ba#ery?
Li-Ion Ba#ery Basics Max Op Temperature is 60 0 C (140 0 F) OpXmum Temperature during use is 68 0 F (For Maximum Capacity and Cycle Life) Charging at very cold temperatures not possible. Charging at high temperatures very undesirable. Electrodes change size during charge/discharge. Cheap cells fail more ogen, somexmes catastrophically! (Ask Samsung and Dell) Most USB Packs can t be charged while being used. Li-Ion Polymer cells are generally be#er quality.
Recharge Time Ba#ery Recharge Xme is a funcxon of capacity consumed and charge rate. Most USB Ba#eries are charged at 1-2 Amps 10 A-hr Ba#ery will take about 6-12 hours to recharge. 20 A-hr Ba#ery will take about 12-24 hours to recharge A few USB ba#eries are supplied with a Faster dedicated Charger (non USB Charging), but these typically require access to 110Vac. First 80% charge is most efficient, self heaxng occurs during last 20%
Other ConsideraXons Is your car ba#ery going to be drained if leave the USB ba#ery connected in your car overnight? How important is it to know remaining state of charge? Short Trips vs. Long Trips Short Trips reduce likelihood of ba#ery gejng adequate charge
Case Study My Requirements: Will be used for short and long trips in the car May remain in car powering devices overnight. Front Panel Remaining Capacity Indicator (0-100%) Power 2 devices (WIFI Hotspot Charged Separately) Must also power devices while being charged. Must be made with high quality Lithium Ion Cells Use of inverter plugged into cig lighter for 110 V 20 A-hr Minimum capacity 3-4 hour Maximum recharge Xme.
My Preferred Choice RAVPower 23000mAh Portable Charger 4.5A DC Output External Ba#ery Pack (3-Port, 9V/12V/16V/19V/20V, LCD Display) for Macbook, Laptops, Smartphones - $99.99 Features: Hiqh Quality 23 A-Hr Lithium Ion Polymer (Gel Polymer) Fast Charging 20V@ 2A (4X standard USB charge) Can be charged while powering devices 500 Charge/discharge cycles Can also charge Laptops Comes with a short coiled USB cable and laptop adapters Link to Purchase h#ps://www.amazon.com/gp/product/b00hfmubyg/ref=oh_aui_detailpage_o09_s00?ie=utf8&psc=1
1 st Alternate (+) (+) $54 OpXonal Car Charger OpXonal Home Charger $13 $16 (1) Qualcomm Quick Charge 3.0 RAVPower 20100mAh Portable Charger QC 3.0 Input & Output, USB C / Type-C Port (2) Car Charger RAVPower 36W Dual USB Car Charger with Quick Charge 3.0 (4X Faster) Link to Purchase (3) USB Quick Charger RAVPower 30W Dual USB Plug Wall Charger with Quick Charge 3.0 Link to Purchase Features & Advantages: Hiqh Quality 20.1 A-Hr Lithium Ion Polymer Fast Charging 80% in 35 minutes with either opxonal charger shown. No Inverter needed if used with Op<onal car charger Can be charged while powering devices 500 Charge/discharge cycles Link to Purchase Disadvantages: Less clarity on remaining charge 12 hour recharge unless purchase opxonal charger 15% less capacity
2 st Alternate $33 (1) RAVPower 16750mAh 4.5A Dual USB Output Portable Charger External Ba^ery Features & Advantages: Hiqh Quality 16.75 A-Hr Lithium Ion Polymer Lowest Cost Needs USB Charge source Can be charged while powering devices 500 Charge/discharge cycles Link to Purchase Disadvantages: Less clarity on remaining charge 9 hour recharge unless purchase opxonal charger 30% less capacity