Charging an Electric Dirt Bike With a Portable Power Station or Solar: Sizes, Times and Setup
Charging an electric dirt bike with a solar generator works the way you probably hope it does: the bike's own charger plugs into the power station's AC outlet, and folding panels top the station back up while you are out on the trail. The part people get wrong is sizing.
So before a trip to Anza-Borrego or the Pisgah backcountry, it helps to know how big a station, how many panels, and how many hours. We ran those numbers for an adult electric off-road motorcycle with the battery and charger specs Valtinsu publishes for the EM-5, EM-5 Pro, EM23 and EM-5 Ultra, rather than a made up 2kWh example.
Can You Charge an Electric Dirt Bike With a Portable Power Station?
Yes. What a portable power station really is, underneath the handles and screens, is a lithium battery wired to an inverter, so the bike's charger sees it the same way it sees your garage outlet, and the pack itself never touches the station.
The Power Path
Panels or a wall socket fill the station first. Its inverter then changes stored DC into 120V AC, the same conversion the U.S. Department of Energy describes for PV systems in general, and the bike charger turns that back into the voltage the pack expects while the battery management system keeps watching each cell. Roughly 15 percent of the energy is lost along the way, which is the cost of leaving every factory protection in place.
Why the Stock Charger Stays in the Chain
Because it is matched to the pack. The CPSC advises using only the charger supplied or recommended by the maker, and has gone further and warned against universal chargers, which can fit the port without suiting the battery. If yours went missing over the winter, order the 48V EM5 charger or your model's equivalent before the trip.
What Size Power Station Do You Need?
One that holds a bit more than your pack does. Voltage times amp hours gives the pack's watt hours, and since the inverter and charger waste about 15 percent between them, we divide that by 0.85 to land on the station size for a full refill.
|
Model |
Battery |
Stored energy |
Station, 0 to 100% |
Station, 70% top up |
|
EM-5 |
48V 23.4Ah |
1,123Wh |
about 1,320Wh |
about 925Wh |
|
EM-5 Pro / EM23 |
60V 27Ah |
1,620Wh |
about 1,910Wh |
about 1,335Wh |
|
EM-5 Ultra |
72V 25Ah Samsung |
1,800Wh |
about 2,120Wh |
about 1,485Wh |
In practice few riders roll back into camp at zero. Come back with 30 percent left and you are replacing only 70 percent, which is why a 1,500Wh station can handle a top up on the EM-5 Pro between morning and afternoon rides even though it could not take the same bike from flat to full. A second bike doubles every number in the table.
How Much Inverter Output Does the Charger Need?
Far less than the figures floating around online. The 1,000 to 2,000W numbers come from fast chargers on large race bikes and do not apply to a 5A stock charger, which barely loads a mid size inverter.
|
Model |
Charger rating |
Output (V x A) |
Estimated AC draw |
|
EM-5 |
48V 5A |
about 240W |
about 280W |
|
EM-5 Pro / EM23 |
67.2V 5A |
about 336W |
about 380W |
|
84V 5A |
about 420W |
about 480W |
|
Read continuous, not surge Some stations advertise 3,000W surge yet hold only 1,800W continuous, and it is the second number that has to last a seven hour charge. Our draw column assumes about 88 percent charger efficiency, so trust your own label first. |
How Long Does Charging Take From a Power Station?
No longer than at home, provided the inverter can carry the charger. Valtinsu quotes 7 to 8 hours from empty for the EM-5, EM-5 Pro and EM-5 Ultra on their stock chargers, and the EM23 is a little quicker at 6 to 7.
Refilling half a pack is not twice as fast, though. The stretch above 80 percent drags while the cells balance, and before a short loop we rarely bother waiting for it.
How Many Watts of Solar Panels Do You Need?
More than the label suggests. A 400W panel at 9 a.m. in October, propped against a cooler, is not making 400W, and in typical trailhead conditions heat, dust and angle take 25 to 35 percent off, which matches the DOE note that sunlight at a panel changes with place, season, hour and weather.
|
Solar array |
Realistic output |
Hours to refill an EM-5 |
Hours to refill an EM-5 Pro |
|
200W |
about 140W |
9.4 |
13.6 |
|
400W |
about 280W |
4.7 |
6.8 |
|
800W |
about 560W |
2.4 |
3.4 |
Those hours assume 70 percent of rating, an empty pack and losses counted. A lone 200W panel will lose ground. For one bike and one long ride a day under clear skies, 400W keeps up, but two bikes or the afternoon storms that build over the Rockies in July call for 800W, as long as the station accepts it, since 800W of panels on a 500W input only ever gives 500W.
How to Set Up a Solar Generator for Your Electric Dirt Bike
Before leaving, write down the pack's watt hours, the charger's input watts and the station's capacity and continuous AC rating (the Valtinsu user manual has the bike side), then fill the station at home so the panels only have to keep pace. At camp the panels go out first, ideally somewhere the trees will not shade by mid afternoon and with the connectors off wet grass.
If you just came down from a long climb, leave the pack in the shade for 20 to 30 minutes. Then follow the connection order in your manual (on most setups that means station AC on, charger to station, charger to bike) and hang around for the first charge to see what the station display really shows.
Can You Charge the Station and the Bike at the Same Time?
Most newer stations allow it, a few budget ones do not, and the manual will say which you have. Run the numbers on an EM-5 Pro: its charger wants about 380W, 400W of panels might be giving around 280W, and the station makes up the last 100W itself, losing about 5 percent an hour on a 2,000Wh unit.
Portable Power Station vs Gas Generator
For a 5A charger either works, and the deciding factors are noise, fuel and weather. The station is quiet enough to share the tent site, though three gray days in the Smokies will drain it. Generators keep running through clouds. Many campgrounds still restrict their hours, and they belong well away from sleepers, so plenty of riders pack both and leave the generator in the truck unless the forecast is bad.
Off-Grid Charging Safety
|
Stop and step away Odor, swelling, leaking, color change, odd noises or excess heat all count as lithium-ion warning signs according to the USFA. Unplug only if it is safe, then back away. |
USFA and NFPA put safe charging between 32°F and 105°F, and a dark station sitting in Moab sun in August can pass that easily, so shade comes first. CPSC has seen many battery fires start at night while owners slept, so we do not leave a bike charging unattended at camp either. Dry ground, nothing over the charger, a plug that seats firmly. And no BMS bypass or panel wired straight to the pack, ever.
If the bike quits far from camp, start with our trailside power loss recovery plan, not with charging.
Planning Power for a Weekend Trip
Think in days rather than charges. One EM-5 Pro doing two rides at about 60 percent of the pack each uses roughly 1,940Wh, close to 2,290Wh out of the station after losses, which 800W of panels making around 560W wins back in about four good hours of sun while 400W leaves the station a little lower every evening.
Your own numbers will differ. Terrain, rider weight and the habits that drain range all shift them, so a few rides with the battery percentage noted before and after is worth more than our math.
How We Worked These Numbers
|
We took battery, charger and charge time figures from the spec sheet and the live product pages for Valtinsu adult electric off-road motorcycles in October 2026. The 85 percent conversion factor and 70 percent solar derate are planning margins we use, not lab results. |
Conclusion
It comes down to three matches. Station capacity has to cover the watt hours you put back, the inverter's continuous rating has to clear the charger's draw, which for a 5A stock charger is only a few hundred watts, and the panels have to earn that energy back in whatever daylight the trip gives you.
Get those right and any campsite works as a charging stop. Before choosing a station, compare pack sizes across the Valtinsu electric dirt bike lineup. And keep the stock charger in the chain.
FAQs
Can you charge an electric dirt bike with solar power?
Yes, through a power station. The panels charge the station, the station runs the stock charger and the charger fills the pack. For one bike ridden once a day, we would start at 400W of panels and a station holding the pack's watt hours plus about 15 percent.
Can I charge my electric dirt bike with a generator?
Yes. The stock charger plugs into its AC outlet like a wall socket, and at 280 to 480W a 5A charger is an easy load even for a small inverter generator. Run it outdoors, away from tents.
How many solar panels do I need to charge an electric dirt bike?
Count watts, not panels. An empty EM-5 Pro needs about 1,910Wh with losses, which is roughly seven sun hours from 400W or three to four from 800W if the station's solar input can take it.
Can I charge an electric dirt bike with a portable power station?
Yes, as long as two specs line up: usable capacity for the energy going back in, and continuous AC output above the charger's draw. A 2,000Wh station refills a 1,620Wh pack. For trail top ups, 1,500Wh is usually plenty.
How do you charge a 48V battery with a solar panel?
Not directly. Panel voltage wanders with sun and temperature, so the panels fill a solar generator and the matched 48V charger, a 48V 5A unit on the EM-5, does the charging from there.
Can I charge my battery directly from a solar panel?
We would not, unless the bike maker sells hardware for it, since a bare panel cannot cap current or stop at full the way the stock charger and battery management system do. Panel, station, charger, battery is the safe order.
How long does a 400W panel take to recharge an electric dirt bike?
Plan on most of a sunny day. Real output from 400W is closer to 280W, so an empty EM-5 takes about 4.7 hours of good sun and an EM-5 Pro about 6.8.
How can I charge my electric dirt bike off grid?
With a solar generator, a gas generator or both, sizing the station to a day of riding and keeping the stock charger in the loop. On trips longer than a weekend, a rough tally of energy used against energy coming back keeps the station from running flat.
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