solar with magnetic charger

I'm thinking of using this while on long bicycle tours to charge 18650 batteries.
All comments welcome.

solarchgr by F/8, on Flickr

magchgr by F/8, on Flickr

Solar charger is 5000mah

The biggest problem with these small sized combined solar panel and battery banks is that the small solar panel is really insufficient for charging the battery especially if you are using the battery bank to charge up devices. The one I tested a few years back would have taken around a 5-7 days (say 6 hours of good sunlight) to charge up its 5000mAh battery from flat.

Some manufacturers of the ones in your pic are now putting disclaimers on their solar powerbanks along the lines of note do not take solar as main power source as it mainly for topping off, due to the limited surface of the solar panel. "

The other reason I am not a huge fan of the solar chargers + lithium ion battery packs is that the battery pack directly under the solar panels get really hot in direct sunlight. Lithium batteries do not like charging >40C and most charging controllers will shut down when it goes over this temperature. I've measured the surface temperatures of my panel and under my panels on my backpack in sunny 30C conditions, and it can reach >40C pretty easily without insulation.

I've also been tempted by these hand held solar panels. Is the technology there yet? I think not. maybe a foding panel with 10x the surface area, but even then, I doubt any reasonable charging times for an 18650. As mentioned above the heat shielding would be a problem as well.

lightknot said:

I've also been tempted by these hand held solar panels. Is the technology there yet? I think not. maybe a foding panel with 10x the surface area, but even then, I doubt any reasonable charging times for an 18650. As mentioned above the heat shielding would be a problem as well.

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You'll die of old age before you charge anything up, especially batteries/cells that are close to depleted.

We've got good 21w jobbies from Anchor and others, that would be much faster.



There's my little Sunkingdom 14w folder charging up a Ruinovo 4x18650 power bank at about 1.8A right after hurricane Irma last September. I was out there for 3 hours and got it pretty well charged up.



There it is with two 30w 12vdc panels doing about 3.5A and charging up 12v mother batteries under the bench.

Chris

Thanks all; saved me money and time.
Chris; your photos did not show up.

quinlag said:

Thanks all; saved me money and time.
Chris; your photos did not show up.

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After I posted them, I moved them between Flickr albums and then deleted the ones in the wrong album. Even though I could see them, I guess you couldn't and so I reposted them to Flickr and then to here.

Chris

quinlag said:

Thanks all; saved me money and time.

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The Olight Universal magnetic charger does work nicely though. I use that in my hiking solar kit. I would suggest spending your money on a decent powerbank, and a better and larger solar panel.

There are a few other threads here with members who also use portable USB solar panels.

I've used various portable solar panels for a while now.

My first was the ICP Global iSun Solar Charger 2.2W that I bought in 2002 (you could daisy chain so I used 3 together to try increase the solar power). The Coleman Exponent Flex 5 that Amazon tells me I bought in 2005 was similar to the folding panels of today. But these were quite woeful in comparison with newer panels today. I still have them in a storage box somewhere.

Fast forward to now, and I've got various Goal Zero panels from around 2012 to 2014 (the Second Gen Nomad 7W, 3rd Gen Nomad 7W, 1st Gen Nomad 13W), the Instapark Mercury 10 solar panel (my favourite panel for a while ), and a few of the newer higher efficiency panels - a Blitzwolf 20W tri-fold panel, a Sunkingdom 6.5W panel, the Sunwalk 6.5W panel, and some various cheap 6W panels I picked up for testing.

I use my panels on long distance hikes so weight is probably more an issue for me than for bike touring.

My current panels weigh:

• Goal Zero Nomad 7W 430g
• Goal Zero Nomad 13w 750g
• Instapark Mercury 10W 500g
• Blitzwolf 20W high efficiency panel 550g
• Sunkingdom 6.5W high efficiency panel 250g
• Sunwalk 6.5W high efficiency panel 125g

The Blitzwolf works really well (and I have also tested an Anker 21W similar panel last year). I would take it if I was hiking in a group.

But for solo hikes, I am preferring the stripped down Sunwalk 6.5W panel as it is my lightest, but still performs well. I did a 100km hike in November and a 250km hike in January and I took the Sunwalk 6.5W panel and did not baby it. It sat in a dry bag in the external pouch of my backpack when not used, and strapped to the pack when being used. It functioned well.

Back in 2013 I took both the GZ Nomad 7W and the Instapark Mercury 10W to Nepal for a month. They could charge a 1000mAh camera battery from flat to full in around 2.5 hours (strapped to a backpack). At the time, I also took two 5000mAh powerbanks. These could not charge at high current (limited to the original USB spec 0.5A), and would take around 2 days to charge to full with the GZ and Mercury panels.

Now there are higher efficiency panels, and these panels have controllers that can output higher current, and newer powerbanks can charge at higher current as well. With my hiking use of the Sunwalk panel I found it performed quite well in non-ideal sunlight, and would restart charging when exposed to sunlight which some of my other panels would not do.

I had it attached to my pack and while walking and did not always have it facing the sun, nor at an ideal angle and occasionally under tree cover. Despite this, it managed to charge up my fully flat 10000mAh Xiaomi battery bank almost halfway in around 5-6 hours walking. It would charge quicker in more ideal conditions.

Thanks keithy; very helpful info; I have a 30w instapark panel I use to keep my 12v "hurricane" battery charged; It's been used and abused for years and still works fine. I'm probably going to order the 10w instapark.

Thanks for the update Chris.