As modern Devices and technology becomes increasingly useful in the outdoors, finding a way to keep it charged can often be the next challenge.
Currently I am aware of Three reliable methods that are sufficiently portable to be useful hiking;
1. Carrying Charged Batteries
Disposable Alkalines for my Head Lamp, or Rechargeable NiMH(*1)
- Simply and probably the most light weight option.
- Common batteries can be swapped between low and high priority devices as required.
- Low Set up cost.
- You need to ensure your batteries are full charged before you leave home using a Battery Tester. / Charger.
- How many batteries should you carry?
- Regular trips can make disposable batteries expensive.
- Temperature changes can greatly affect how long Batteries last, particularly NiMH.(hotter -shorter/ cooler – Longer)
- You must carry all batteries out with you.
2. Power Bank
They come in two types:
a) Simple USB charged, Closed Case Cell.
- Simply and light weight.
- Low to Moderate Set up cost.
- Depending on the device you are charging – can hold a number of charges.
- Technically can be re charged from a solar panel USB input(not tired it)
- re charges limited / by the device.
- Only compatible with devices that can be USB compatible
b) A Charger /Power Bank Combination
- Can act as both a Power bank and Charger.
- In Power bank mode any A class batteries (NiMH or Alkaline) can be used to charge USB capable devices.
- In combination with an external Goal Zero Solar Panel, it acts as a charger for A class batteries as well as act as a power bank to maintain a steady input power(*2) for a dual charging USB device.
3. Solar Charging
There are some good quality Solar systems around now days, most or which are a combination of a panel and a battery charger/ power bank.
- All you require is UV light, and there is plenty if not to much of that in New Zealand. Modern Panels will charge well in most conditions including light rain…
- Generally greater weight than carrying batteries or a power bank
- You still have to carry at least 4 -6 AA batteries to allow rotation and USB charging if you are using other electronics beyond a smart phone.
- You need all of your outdoor electronics to use compatible batteries or USB charging.
- Greater Set up cost
My Power Picks
All of my outdoor electronics/ devices either use AA or AAA batteries or are compatible with USB charging from AA Batteries.(*3)
Single Day Hikes;
- I carry 6 freshly charged AA NiMH batteries, 2 in the GPS, and the 2 as GPS spares, which combined with the 3rd pair can be used to run my UV Water Steriliser .(very low power requirement)
- 4 x AAA Disposable Alkaline Batteries in my Head Lamp, and 4AAA as spares(*4)
- A Power bank for emergency recharge of phone (gives me approx 3 days on flight mode.)
Overnight or Multi Day Hikes;
- Goal Zero Nomad 7 Solar Panel with the Guide 10 Plus – Charger /Power Bank combo))
- 6x NiMH AA Batteries, 2 in GPS, and 4x in the Guide 10 (solar charging as soon as a pair discharged batteries are rotated in)
- 4 x AAA Disposable Alkaline Batteries in my Head Lamp, and 4AAA as spares.
Battery Maintenance and Organisation
- Before I use new NiMH Batteries I always add a label identifying the purchase date of the battery, which is invaluable later for calculating a replacement date.
- I carry all charged batteries in Battery Containers which help to prevent accidental discharge and are preferred by airlines.
- To date I have always had pairs of batteries from different manufactures on hikes to avoid mixing charged with discharged cells, although now having moved to entirely Eneloop cells (for reliability) I colour code pairs of the same purchase date.
- Power Banks and NiMH Batteries need to be regularly charged when not in use to maintain their performance ( just like your smart phone)
- As a minimum, try and find a NiMH charger that also has a discharge cycle built in. Even better a charger with a capacity to charge different size batteries and a digital readout.
Goal Zero Performance
- In the New Zealand high UV; it takes approx 4 hours to charge 4x NiMH A class batteries via the Nomad 7 Panel under a clear sky(although be careful to shade the charger well)
- Walking in and out of sky cover (Bush and clearings) it takes the same combination about 6-8 hours depending on how much your under cover to achieve the same full charge.
- The Power Bank requires 4 AA or 4 AAA to start charging, it doesn’t matter what state of charge the individual batteries are.
- The Power Bank can be charged from a USB power source in the absence of good UV conditions.
- Charge just batteries or divide the charge between the batteries and a USB device.
- The Power Bank has an LED light – always handy when your head lamp batteries need changing.
- The solar panel also works perfectly fine through the deck of my plastic sea kayak! I just strap it across one of the dry bags in the sealed gear compartment.(Mine is a light yellow – not sure if that makes a difference?)
- Goal Zero Solar
- Batteries: Discharging at High and Low Temperatures
- The Best Rechargeable Batteries and Chargers Of 2019
(*1) Currently my favourite NiMH batteries are the Panasonic Eneloop,(slow discharge) which are good for around 2000 charges, although I see there are now Eneloop Pro batteries sold with a longer discharge life.
(*2) When charging a Modern USB smart device from a solar panel walking under shade or a cloud passing over the sun will cause charging input power to fluctuate in a way that will cause the device to recognise it as an unsafe charging source and stop / prevent charging.
(*3)Using a common battery type between electronics has the advantage that you can swap batteries around depending on the priority of the device when conserving power.(ie: taking batteries from your charger and GPS to for to run a UV water filter for a drink bladder fill, and then putting them back into the original devices.
(*4) While the batteries in my Head Lamp simply last for ages, its less that I need to carry spares, more that they will always run out on that day that becomes an unexpected night – when i am not carrying them:-)
(*5)The Goal Zero Nomad 7, while still listed on the Website, seems to have been replaced by the newer generation Nomad 7 Plus in New Zealand outdoor stores.
(*6 When buying Goal Zero Gear, make sure that the solar panel and Power Bank has the correct output power for your device. (The Nomad 7/ Guide 10 has and output of 1 amp, with the Nomad 7 Plus/ Venture 30 Power Bank being greater.