A power bank is the better primary source for small pet devices such as a GPS tracker, because its stored energy is fixed and known. A folding solar panel’s real output depends on sun, cloud and season, and runs well below its rated watts, so use it to extend a power bank on a long outage, not to replace one. Jump to the picks.
BigBlue, Goal Zero, INIU, Anker, Tractive, and Apple are trademarks of their respective owners; EmergencyPetPrep is not affiliated with or endorsed by any of them.
What Counts as a Small Load
Every power-station comparison on this site assumes a load big enough to need one. This page covers the load one size down, devices that draw a few watts to perhaps 15-20W (our scoping for this page):
- A pet GPS tracker. Tractive says the DOG 6 runs up to 2 weeks per charge and charges in about two hours. Tractive also says Live Tracking uses more power than default tracking.
- A battery aquarium pump. The Aquarium Co-Op Air Pump with Battery Backup (single outlet) draws 1.2W and runs about 20 hours continuously on battery, per the maker’s product page, which lists 8 hours for units sold before 8/1/2024.
- A carrier fan. Check the wattage printed on your own unit’s box.
- A phone running a pet camera app. The phone is the load you are charging.
If your list includes a mini-fridge, an aquarium heater or a reptile basking lamp, you have outgrown this page. Our Jackery vs EcoFlow for pets and best portable power stations for pets guides cover that tier. For refrigerated medication, see our pet medication refrigeration during an outage guide, and ask your veterinarian about dosing or timing. Before running any powered medical device from a bank or panel, check the device’s own power requirements with its manufacturer.
What a Solar Panel Delivers Compared With Its Rated Watts
A folding panel prints a wattage on the box: 20W, 28W, 30W. That is a lab rating under ideal conditions, not a promise about what reaches your device in a parking lot. BigBlue’s own page for the SolarPowa 28 says as much: actual power is less than the rated power because some is lost as heat in conversion, and because of weather, season and location.
Goal Zero says something similar. Its Nomad 20 page notes that solar charge times depend on factors such as “elevation, temperature, time of year, angle and position to the sun.” The same page lists a Yeti 200X power station charging in 11 to 22 hours, a 2x range on the same hardware.
OutdoorGearLab measured the SolarPowa 28 in side-by-side testing against other folding panels. It tested the version with a built-in ammeter, which is not the no-ammeter version on BigBlue’s page cited here. Its table lists 2318 mAh generated in one hour of direct sun and 551 mAh in one hour of indirect sun. At a typical 3.7 V cell voltage (our conversion), that is roughly 8.6 Wh in an hour of full sun and about 2 Wh in an hour of indirect sun. A 28W panel would need to deliver its full nameplate output for an hour to make 28Wh.
None of this makes the panel a bad product. The number on the box describes a lab, not your driveway on an overcast evacuation morning.
Charging While Evacuating: A Panel on the Dashboard vs. a Bank You Charged Last Month
Suppose you are driving out of a wildfire zone with pets in the car and need to keep a phone and a GPS tracker alive. A folding panel on the dashboard or back seat charges in fits and starts, at whatever angle the car happens to face, through whatever cloud the sky has, and not at all after dark. A power bank charged the week before delivers its stored capacity on demand, at 10pm on a cloudy highway just as at noon.
That is why the bank is the primary device and the panel is the backup. A panel earns its place on a multi-day outage or evacuation, once the bank is spent and grid power or an outlet is still a day or two away. On a single overnight event it solves a problem you probably do not have yet.
Bank and Panel Side by Side
A watt-hours-per-pound comparison is fair for a power bank and misleading for a panel, because a panel stores no energy. It only converts sunlight while the sun is out.
| Device |
Weight |
Stored energy |
Delivered energy |
| INIU 20,000mAh power bank |
11.1 oz (0.69 lb) |
~74Wh nominal (our arithmetic), available once charged |
Does not depend on weather, time of day or season |
| BigBlue SolarPowa 28 folding panel |
1.5 lb |
None |
~8.6Wh per hour in direct sun and ~2Wh per hour in indirect sun in OutdoorGearLab’s test; nothing after dark |
The panel’s value is over days, not hours. Left connected across a multi-day outage, it keeps adding watt-hours to whatever it is charging while the sun is out.
Keeping a Pet GPS Tracker Charged for Days
When an evacuation outlasts the tracker’s battery, you need a way to recharge that does not depend on the outlet you left behind.
Tractive says the DOG 6 runs up to 2 weeks on a charge and takes about two hours to recharge. No battery capacity in mAh or Wh for the DOG 6 is published in the sources cited here, so we cannot say how many refills a bank provides. The bank holds about 74Wh nominal (20,000mAh at 3.7V, our arithmetic); check your tracker’s manual for its battery size.
The panel’s role is the multi-day extender: once the bank is depleted, connect the panel to the bank, or to the tracker if it charges from a direct USB input, and it adds watt-hours in good sun. It is slow and does nothing at night.
One device here needs neither: an AirTag. It runs on a replaceable CR2032 coin-cell battery. Apple’s support page describes the tool-free swap, and Apple’s AirTag page says it works for more than a year on a standard battery. The prep move is a spare CR2032 in your go-bag. If you are weighing an AirTag against a dedicated collar tracker, see our AirTag 2 for pets guide, and our GPS tracker without cell service guide covers what happens to trackers once cell towers go down.