If you are planning to go bikepacking or hunting during the long weekend, you might be considering mobile and off-grid power sources to recharge your battery. Although there are several alternatives (solar, off-grid inverters, electric cars/trucks, etc.), you might be wondering: Which is the best practice/device to adopt.
Although an electric car’s electrical system or solar panels are somewhat effective at recharging your e-Bike batteries, the most efficient (and reliable) alternative is to carry a spare battery pack.
However, a spare battery pack is only half the solution since you will have to keep the other pack recharging in the meantime. So to help you with this, I’ve prepared a mobile electric bike charging guide using topics such as:
Charging your eBike battery using your car/truck
Getting solar panels to recharge your batteries
Using a power bank to top up your batteries
A handful of tips on how to maintain the battery life of your eBike
Let’s get to it.
Charging your eBike Battery using your Car/Truck
Thankfully, you don’t need to preplan your routes to stop at coffee shops, restaurants, or bike shops to recharge your eBike battery; you can safely charge your battery in the comfort of your own car/truck as long as you have the proper equipment and know what you are doing.
The batteries in your car (electric or otherwise) utilize DC (Direct Current) power. Meanwhile, most chargers are designed to plug into Mains AC i.e., the wall outlet of your home; hence, they require an AC (Alternative Current) power source with 120V or 220V. (for the US, it’s 120V, whereas, for Europe, it’s 220V.)
Unfortunately, since your car deals with DC (Direct Current), you need an inverter (see here to know what size inverter to charge an ebike) to convert the DC power into AC before you can plug in your charger.
The original AC battery charger plugged into a car inverter might seem inefficient (since you’re converting DC to AC and back again). However, using your car, truck, or RV is the safest method to charge your eBike battery. (As you should always try to use the stock charger.)
There are other cheaper options where you can rig up buck/boost converter circuits (and a plethora of adapters) to charge your batteries. But unfortunately, this bypasses the stock charger and can degrade the batteries, resulting in low range and short circuits which can also then lead to your ebike motor cutting out.
How to Setup a Car Inverter
There are two ways in which you can set up a car inverter for your vehicle, you can either plug it in via the 12V car adapter (cigarette lighter socket) or directly hook it up to your battery via crocodile clips.
The former method is the easiest because you can easily unplug the inverter. However, you will be limited to 120W-240W of power, whereas the latter requires a lot of cable management, drilling, and setting up inline protection fuses.
Nonetheless, whenever the inverter is (properly) set up directly with your battery, it can draw upwards of 1000W. (Ideal for fast chargers.) So depending on your charger, you might have to go for the high-power option. (I’ll talk more about sizing up an inverter in a later section.)
For now, here’s how you can set up a car inverter with the 12V cigarette lighter adapter:
First, take out the inverter and remove the black and red screws on the rear panel (these represent the positive and negative leads.)
Take the cable with the 12V socket adapter and insert the lugs/rings of each colored cable into the corresponding pins on the inverter. Make sure you don’t mix up the two colors.
Put the screws back on and make sure they are tight.
After that, plug the 12V adapter into the cigarette lighter socket and turn on your car.
Finally, switch on the inverter (most inverters have an “I/O” power switch) and see if any displays or LEDs switch up.
Now you can plug your charger into the AC outlet of the inverter. (If you are worried about arcing, you can plug in the charger before switching on the inverter.)
Don’ts of Using a Car Inverter
As you can see, setting up an inverter is pretty simple. That said, there are some things you should not do when using an inverter.
Never use the inverter when the engine is off: The Lead-Acid car batteries used on automobiles are not designed to power small electronics for extended periods. Therefore, when you use the inverter when the engine is powered off, the battery will drain faster; hence, the best time to use the inverter to charge your phones or eBike batteries is when you are driving.
Never mix up the red and black wires: The red and black wires (and terminals) of an inverter represent the positive and negative terminals of a battery. If you switch these up, especially when directly hooking up to the battery, it can cause the inverter to display an error (see here how to fix ebike error codes). Also, if it’s a particularly cheap inverter, the device will malfunction. (Since low-end devices do not include reverse-polarity protection.)
Always use appliances within the rated power limit: If an inverter is rated at 300W, you cannot use appliances that consume more than 300W, at least not continuously. So you should never use a high-power charger with a low-power inverter. It might sound an alarm and disconnect the charger. (It automatically resets when you switch it off.)
Don’t Block the vents on the back of the inverter: The inverter heats up whenever it’s in use, and whenever it gets too hot, the inverter switches on a cooling fan to cool down (just like a case fan on a PC). So to avoid overheating, make sure it has enough ventilation. (I know this is difficult when you’re inside a car, but as long as you keep it under or above a seat without blocking it off, it will be okay.
How to Size up an Inverter for your eBike Charger
There are two types of inverters: pure and modified sine wave (MSW). Simply put, modified sine waves are the cheaper option, and they are good enough for laptops, electric kettles, battery chargers, and other “solid-state” appliances that don’t include motors.
As I said, an MSW inverter is good enough for battery chargers, and when you’re shopping for one, you should always get an inverter with a continuous wattage rating higher than your charger’s.
If you have no idea about the power consumption of your charger, here’s how you can size it up:
Find the input/output voltage and current values of your charger (most often, it is labeled on the device itself)
Multiply the voltage value (for example, 48V) with the current value (say, 2A)
The product of these two will give an approximate value of the power of the charger (in our case, it would be approximately 100W)
Then you can pair it up with an inverter higher than this wattage.
I recommend going for twice the wattage as the inverter won’t heat up, start the fan and cause a ruckus.
Car Inverter Recommendations
Here’s a quick list of some of the best car inverters on Amazon.
Bestek 300W Power Inverter: If you need to charge laptops, phones, and low-amp eBike battery chargers, this is the most reliable car inverter. This bad boy can handle 300W of continuous current and it has a peak watt rating of 700W. It has two AC outlets, so you can rapidly charge a phone/laptop using a stock fast charger. On top of that, it has two USB ports with 2.4A current rating. (Although I wouldn’t put too much faith in it.)
Cantonape 1000W/2000W Inverter: If you have a high-power charger (such as a 48V/5A or 72V/5A), you cannot go wrong with a 1000W inverter. You’ll get your eBike batteries and other gadgets recharged in no time. However, this device is a bit bulky, and you may need to fix the cables yourself. (Thankfully, there is a 12V socket adapter cable.)
LVYAN 2500W Pure Sine Wave Inverter: If you wouldn’t mind spending upwards of $150 on a car inverter, I highly recommend LVYAN Pure Sine Wave inverters. I have firsthand experience of using these for my backup power system, and I have to say, it is one of the best investments I’ve made. Unfortunately, this is a chunky boy and doesn’t come with the plug-and-play car adapter; hence, you will have to get extra-long cables (the included cables are too short), lugs, fuses/circuits breakers and hook it up directly to a car battery. Also, the fan is extra-loud at high temperatures but won’t switch on if it’s running under safe temperatures (less than 100 degrees).
Getting Solar Panels to Charge your E-Bike Battery
If you are not keen on using a gas-powered car to charge your eBike batteries, you have two other alternatives: solar and power banks. In this section, I’m going to elaborate on how you can charge an eBike battery using solar.
There are two ways in which you can use solar power to recharge: either plugging in directly or using a solar generator. (A solar generator is a charge controller, inverter, and a power bank all rolled up into one.)
Direct Solar Charging
Setting up direct solar charging for your eBike battery is definitely impressive, although impractical and unnecessary. With direct solar, you won’t be able to use your original smart charger; it will be exclusively working with DC power. (No inverters involved.)
Getting a solar panel and hooking it up to a charge controller is easy. The hard part is getting the charge controller to recharge your bike battery.
If you choose to continue on this path, please remember that you are going to have a hard time modifying the charge controller to recognize your battery. Variables such as voltage, data pin signals, adapters, and protection circuits affect the recharging aspect.
As you will be bypassing the original charger, your battery is not going to have the best protection or efficiency; hence, I recommend staying away from “battery-free inverter-free direct solar charging setups.”
That said, brands such as Electrify Bike Co and QUIETKAT have experimented with the direct solar charging method for their eBikes.
How to Use a Power Bank to Charge your Battery
And finally, the best “remote” alternative to charge the batteries on your electric bikes’ is via a power bank/solar generator.
Now mind you, I’m not talking about those small 10,000mAh power banks used to power mobile phones, I’m talking about those beefy microwave-oven-sized power banks that people use for camping. These large power banks include a large battery, built-in inverter (most often pure sine wave), and a charging interface for solar and mains AC.
Most medium-sized solar generators include 700-ish Watt hour deep discharge batteries and depending on the battery capacity of your eBike, it could get a full charge out of a power bank. (A typical 48V/16Ah eBike battery would need around 768Whs for charging to full capacity.)
Therefore, most power banks/solar generators won’t even last the weekend. This is why I recommend supplementing your setup with a spare eBike battery and solar/car inverter charging.
Speaking of which, you can recharge solar generators using AC power or solar panels. Both do an equally similar job, but you have to use them under the right circumstances. (car inverter charging while driving and solar while camping.)
Best Portable Power Banks to Recharge your Bike Battery
Here are some of the best solar generators to keep your eBike battery topped off when you are away from civilization.
BLUEETTI EB70S 800W: BLUETTI solar generators are compact and affordable. Although the EV70S can only pack 716Wh, the LiFePo4 battery would last up to 3,000 cycles. Therefore, it’s guaranteed to last almost four lifespans of your Lithium Ion eBike battery. The EB70S can also charge via solar and includes an optional 200W solar panel system. Unfortunately, the EB70S takes around 6-7 hours to full recharge via solar (due to the 8A current limit) and 4-5 hours via Mains AC.
Jackery Solar Generator 1000: Jackery is also another great alternative. Although there are 200Wh and 700Wh options, I recommend the 1000Wh generator with 100W solar panels; it is light, efficient, and has enough juice to top off your eBike battery. Unfortunately, it’s got lithium batteries and a 180W solar limit.
ECO FLOW Delta Pro: If money isn’t an issue and you have enough space on your car/truck, I highly recommend the ECO FLOW Delta Pro. This power bank has tons of juice (single unit starting at 3600Wh) and can top off your eBike batteries perpetually since it has 1600W solar input capacity. It’s got LiFePo4 batteries and would last a long time. On top of that, you can expand the capacity by installing a couple of additional battery modules (to reach a maximum of 10.8kWh.)
Tips on How to Maintain the Battery Life of your Electric Bicycles
Here’s a quick guide on how you can take proper care of your eBike and keep maximizing battery life for better range and longevity.
Top-Off your Ebike for Almost 12 Hours Before Using it for the First Time
Although you might be excited to try out your eBike as soon as you purchased it or had it shipped, I highly recommend keeping the battery completely charged for around 12 hours before using it for the first time. It will top up all the li-ion cells to the same voltage, improving the full capacity of the battery and ensuring the maximum battery life is maintained.
Regularly Maintain the Batteries’ State of Charge (SOC)
Li-ion batteries lose capacity with time, so if you won’t be using the eBike for a week or so. It’s best to maintain the cycle life of the batteries by recharging them and maintaining a state of charge somewhere around 30%-60%.
Keep your Battery Management System Safe from Extreme Temperatures
Don’t let the freezing cold or a hot summer day ruin your battery. If your battery gets too hot (whether it’s direct sunlight or overheating during charge/discharge cycles, the cell chemistry will be affected. If it gets below freezing, the electrolytes might freeze and do the same. So always remember to keep your battery inside when you are not using it.
Don’t Leave your Battery Charging Overnight
Studies have shown that keeping your battery plugged in overnight can degrade battery life. Besides, it’s a waste of energy and a potential fire hazard (especially when using low-quality chargers). So I recommend taking it out of the charger or using a smart plug (with a timer to switch it off).
Here’s our guide on setting up remote charging options for your eBike battery. As we’ve discussed: it’s all about the inverter. So as long as you have a decent inverter along with solar or gas (and sometimes, a spare battery), you will be able to enjoy your eBike free of worry.
Andrew Strider is an electric bike enthusiast. He currently owns 5 electric bikes and is an active member of his local electric bike club where he is able to test many other models/brands a few times a month.
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