# Solar Power Bank



## maryozano (5 mo ago)

I'm about to embark on a six day sailing trip offshore. I want a decent compact solar powerbank for my phone. Ive seen some decent looking ones on Amazon for under 50 quid. Any recommends?


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## Happy Joe (10 mo ago)

USB power banks are usually rated in milli-ampere hours (mAh) in most cases the more power the better (higher mah is better) I have one, originally for backpacking, that is rated at 20,000 mah (which translates to 20 amp hours) it is more than enough to keep my phone and blue tooth speaker recharged for several days (a week or more of intermittent use)... I would stay away from any USB power banks that do not list their power storage capacity, and any that do not recharge from, at least, several square feet of solar cells, as far as I can see they are, likely, all made in china with chinese quality..

Not sure how well your cell phone will work if you get far away from the cell towers of civilization, though...

When I am out side of cell service areas my cell phone can easily last 4 days without recharging. When using it for a lot of talking (in range of cell service) though its only good for a couple of days between charges.
I tried & have a 5 watt (advertised) solar USB charger (folding solar panel array) for my USB power bank; it only barely works, smaller ones would likely be ineffective... be aware that makers of solar cells and panels etc. typically vastly overrate their products...
When camping I have used old solar arrays/panels as small as 14 (advertised) watts (measured power was in the 3 to 4 watt range) to recharge a 35 amp hour SLA (sealed lead acid) battery. My current minimum is 100 watts (advertised power from "reputable" solar companies) for solar recharging a 50 amp hour LiFPo4 battery. 
Last year I experimented with a number of new, 20 to 50 watt panels (from less reputable chinese companies via Amazon) which had actual (measured) power outputs roughly 1/12 of their advertised rating ... one possible conclusion is that chinese companies cannot measure another is that they tend to stretch the truth as far as it will go. Beware...

I keep quite a bit of music stored on my phone and use it to drive the blue tooth speaker when camping (preferably out of range of cell towers).

BTW most sail boats of any size have onboard electrical power sufficient to recharge USB toys...I might suggest you inquire...

P.S. Welcome to the forum!

Enjoy!


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## SdPrada (Mar 31, 2019)

i have a solar powerbank from BEARTWO which is relatively robust and water resistant.
With this solar power bank, you can rest assured that it will withstand any minor impacts and dirt. 2 standard USB ports. Compact and portable. LED emergency flashlight.


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## Happy Joe (10 mo ago)

Here is a link to a top ten solar power/battery bank guide;
Buyers Guide
Be aware that the battery bank solar recharge times seem excessively optimistic, given the size of the solar panels attached to most of the battery packs.
I also only see one bank that is pictured with a folding solar panel., and it, conversely, has the longest advertised battery bank recharge time of those reviewed (something doesn't seem to add up).
Use caution to avoid being ripped off ...

Edit; here is a pic for one of the 30,000 mah, battery/packs/banks that gives (I believe/expect) a more realistic view of expected recharging performance;









Enjoy!


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## Happy Joe (10 mo ago)

On a happier note: the prices on Amazon) for 12 volt, 50 amp hour, lithium iron phosphate batteries seem to be coming down. I now see 12 Volt, 50 Amp hour LiFePo4 batteries in the $200 range (for those who wish to assemble their own much less costly 600 watt hour power station) ... Its what I use, along with a small inverter for tent power (to recharge USB toys and power tunes, lights, etc.

Note, I vehicle camp.

Back packers, and people traveling light, will likely use the above, less powerful, USB battery banks/packs, or similar, due to their lighter weight & better portability.)

Enjoy!


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