Portable Power Station + Solar Panel for Road Trip?

[Joim]

Hi people,

First post, hopefully in the right place. It's also my first time going on a road trip and while on the road we (2 people) want to be able to work around 6 hours every other day. Since we have no experience whatsoever in setting up a "mobile office" I thought I would post some questions here and get some feedback on my thoughts.

I'm looking to buy a portable power station + solar panel for a road trip through Europe (2-3 months). I have found this one (666 Wh) on amazon.de that satisfies my budget and Wh needed (according to reviews the battery delivers the specified Wh or close to it). There is a 100 W solar panel included and they say in the description that it takes 6 hours to fully charge it with the solar panel - this sounds very optimistic from what I have read about solar power so far (like "get a solar panel with 20% more watts than you need", etc.). Is it more realistic to expect 8-10 hours for a full charge? We will be travelling through France, Switzerland, Italy, Spain and Portugal over the next few months (july, august, september) so I assume that sunlight won't be much of a problem.

How I calculated the Wh we need:

2 x laptops (~50 W each) = 100 W, 2-3 hours of charging should provide at least 6 hours of running time = 300 Wh every two days.
2 x phones (~10 W each) = 20 W, 2-3 hours of charging should provide more than enough to keep phones running 24/7 = 60 Wh every day.
1 x mobile hotspot (~15 W), 6 hours of running time (while working) = 90 Wh every two days.

In total we need 300 + 60*2 + 90 = 510 Wh every two days. Is this calculation realistic (and correct)? Rounding up a bit, this means that we need to charge around 5 hours each day (or 10 every other) - according to specification the power station can also be used while it is being recharged, giving us the possibility to charge while working (which is preferable as we probably won't be in camp on off-work days). If this is correct, it seems like a very viable solution for us.

Are there any things I haven’t thought / don’t know of? Thanks for taking the time to read. Looking forward to hearing from you.

[bcroe]

You are on the right track, but the numbers need some adjustment. Lap tops can vary
a lot, but in general are pretty efficient. My Apple typically takes 10W at the AC line
adapter.

A 100W panel will only put out 100W for the most ideal conditions, which never last
more than an hour or so in a day, though you may never actually see more than 80W.

More realistic is 200 or 300 WH a day if you can get good alignment in a sunny sky.
Clouds are PV killers, output may only be 10 to 25% of good sun. I would say plan on
plugging into an AC line periodically, with a power system that can fully recharge in a
pretty short time. The panel might be able to extend the time between line recharges.
good luck, Bruce Roe

[foo1bar]

Hi people,

First post, hopefully in the right place. It's also my first time going on a road trip and while on the road we (2 people) want to be able to work around 6 hours every other day. Since we have no experience whatsoever in setting up a "mobile office" I thought I would post some questions here and get some feedback on my thoughts.

Since this a road trip, I'd get a small inverter that runs off the car battery. And laptop/phone chargers that work off the car battery / cigarette lighter. Probably your phone charges using a USB cable - so there's lots of cigarette-lighter-to-USB-charger doohickies around that you can get.
I probably would also get a splitter for the cigarette lighter so that you can plug in two things at once. (just not too high of power on them at the same time)

[Joim]

You are on the right track, but the numbers need some adjustment. Lap tops can vary
a lot, but in general are pretty efficient. My Apple typically takes 10W at the AC line
adapter.

A 100W panel will only put out 100W for the most ideal conditions, which never last
more than an hour or so in a day, though you may never actually see more than 80W.

More realistic is 200 or 300 WH a day if you can get good alignment in a sunny sky.
Clouds are PV killers, output may only be 10 to 25% of good sun. I would say plan on
plugging into an AC line periodically, with a power system that can fully recharge in a
pretty short time. The panel might be able to extend the time between line recharges.
good luck, Bruce Roe

Thanks for the info! Just checking to make sure I understand correctly: So even if the laptop charger says 45 W it might actually use less?

Also if I wanted to be able to run off solar entirely I would need more panels? (running in parallel?) I think I read somewhere that the volts and amps of the solar panel are important to avoid wearing the battery down too quickly or starting a fire - so I can't just buy a 200W panel, right?

Since this a road trip, I'd get a small inverter that runs off the car battery. And laptop/phone chargers that work off the car battery / cigarette lighter. Probably your phone charges using a USB cable - so there's lots of cigarette-lighter-to-USB-charger doohickies around that you can get.
I probably would also get a splitter for the cigarette lighter so that you can plug in two things at once. (just not too high of power on them at the same time)

Good points. Should have mentioned that we will be staying in place for 2-4 weeks whenever we set up camp. Still, chargers that will work off the car battery is a good idea. Thanks!

[bcroe]

With your own vehicle, you have access to a battery and motor generator
system. With lighter load, you might run entirely off 12VDC. Adding inverters
will drag down the energy efficiency, converting with losses to line voltage, just
so your equipment can convert it back down (with more losses). Be prepared to
run the motor to take care of your battery.

If often running short of energy, consider upgrading to a full RV system, with an
added parked operation battery besides the ignition starting battery, with a split
charging system. Yes more panels will help, more 12V panels could be paralleled
with the right charge controller. RV place rents are cheap with line supply that
could maintain and recharge while you are there.

The W rating of devices is typically the peak possible amount that might occur.
However the average W might be far less for your device, check it out. A 12VDC
input supply might draw a lot less average W than your line operated supply.

Bruce Roe

[Mike90250]

Your choice for power source is several expensive 100W panels (I would go for 300W) and an inexpensive charge controller, or a large, cheap 300w panel and expensive MPPT controller.
What are your options for recharging the power station battery from external power ?

I also question this description
> 【666Wh / 185200mAh Huge Capacity】:
because 666wh is only 55ah, not 185ah

[Joim]

Thanks for you input, Bruce. Appreciate it. Full RV setup sounds very neat, but I don't think I have the budget for that (have been looking here: https://www.mobile-solarpower.com/). Budget is currently €700 but might be able to push it to €800, though I'd rather not if possible.

Your choice for power source is several expensive 100W panels (I would go for 300W) and an inexpensive charge controller, or a large, cheap 300w panel and expensive MPPT controller.
What are your options for recharging the power station battery from external power ?

I also question this description
> 【666Wh / 185200mAh Huge Capacity】:
because 666wh is only 55ah, not 185ah

Thanks for your reply!

Hmm. Not sure what to do here as the budget is already pretty tight. Might be able to push it to €800, but that's gonna hurt elsewhere.

I guess we can charge the power station from the car's 12V whenever we're driving, but that might not amount to more than 1 hour / day. It's hard to say since we don't know how far from the climbing spots we will be setting up camp. We will try to avoid camping sites when possible to save money, so we can't rely on getting power from those places. Maybe we should look for a small coffee shop or the like, where we can ask them nicely if we can charge it there whenever we go to get supplies in the city

About the Wh vs. Ah: So far all the portable power stations I have found are specified to operate at around 3-4V instead of 12V. Not all of them specifies the voltage, but I just assumed it to be Wh / Ah = V. What do you make of that? I only have basic understanding of electricity so I don't know what to take from it.

[SunEagle]

Your choice for power source is several expensive 100W panels (I would go for 300W) and an inexpensive charge controller, or a large, cheap 300w panel and expensive MPPT controller.
What are your options for recharging the power station battery from external power ?

I also question this description
> 【666Wh / 185200mAh Huge Capacity】:
because 666wh is only 55ah, not 185ah

My guess is the Wh and Ah rating is just pure advertising hype. Most of those "portable" systems never provide what they claim to and also as you noted don't charge back up via a solar panel system in the time frame they claim.

[Mike90250]

An hour of charging from the car alternator, which in most cases, can produce 60A @ 15v , will far outstrip what a 100w panel can produce in a day.

> About the Wh vs. Ah: So far all the portable power stations I have found are specified to operate at around 3-4V
> instead of 12V. Not all of them specifies the voltage, but I just assumed it to be Wh / Ah = V.
> What do you make of that? I only have basic understanding of electricity so I don't know what to take from it.

A portable battery pack is generally going to be a 12V system. 3V or 4V is unusable. Even cell phone sized battery packs ( for recharging cell phones) are around 5 or 6V.
All I can say is the numbers for that battery pack look strange.

[chrisski]

For planning purposes, this is a chart I made of amps from mu 12 volt battery bank. I track my power in amp hours, but watt hours is a better way to do it. To convert these numbers to watts, multiply by 12 volts.


Battery Draws 12 Volts 2020 07 03.jpg
Please note my laptop while plugged in pulls 120 watts. I was told to plan for between 150 w and 250 w on a laptop. I left off the microwave which pulls 155 amps, which is around 2100 watts.

There's going to be a lot in the vehicle you travel in besides the items you mentioned.

A rule of thumb I've been told from other RVers is that you need two golf cart batteries and 300 watts of panels to go boondocking. That takes all that complicated math out of it. May work for a while, but if you live out of the trailer without monitoring the batteries, especially after a few cloudy days, you could find those batteries well under what you need. Actually best to do a power audit for your system prior to installing the system. Also, requirement for panels can vary by location. A site like PV Watts can help you plan that.

Buying a generator is easy. You just look at your highest wattage item and buy to run that, and fill up with gas when its low. Solar is a bit more complicated, but a lot quieter.

[SunEagle]

I have bought Jackery Explorer 240, and I think it is the best one in this budget, there are many others that can also fits in your budget.

Those are decent portable power packs. But I would find another solar panel to charge it then getting one of theirs.