Posted: 1/3/25
How to Minimize Charge Times with the Right LiPo Battery Charger
LiPo battery chargers have become essential equipment for most radio control hobbyists, now that LiPo batteries are often preferred over NiCd and NiMH chemistries. And while LiPo batteries charge faster than NiCd and NiMH batteries, there are ways to minimize LiPo battery charge times even further.
For convenience, some ready-to-run RC cars (RTRs) and ready-to-fly RC aircraft (RTFs) come factory-equipped with an appropriate LiPo battery and LiPo battery charger. But many don’t, because the manufacturers recognize that RC hobbyists often either have those items already or would rather choose their own LiPo charger and battery.
If you buy a remote control model that does include a LiPo charger, it will often be a basic, inexpensive charger with limited capabilities. On the plus side, that means you won’t immediately have to go purchase a LiPo battery charger before you can enjoy your new RC model. However, you might also have to wait hours for the included charger to fully recharge your LiPo batteries.
Sooner or later, you’ll want to upgrade and get a better LiPo battery charger — one that can charge faster, for example, or charge multiple battery packs at once. With that in mind, let’s take a look at some useful features you may want to have on the checklist for your first (or next) LiPo battery charger if you want a faster LiPo battery charge time.
Popular LiPo Battery Charger Features
With so many LiPo battery chargers available, choosing the best one for your needs can be an overwhelming decision. But selecting the right LiPo battery charger is also crucial for getting the best performance and longest life from your batteries, making it a sound investment. Here are some important questions to ask while you search for the right LiPo charger.
Which LiPo charger works with my current batteries?
The LiPo battery charger you select must be compatible with the LiPo batteries you use. Make sure the charger’s voltage and amperage match what your batteries require. It’s generally safe to charge LiPo batteries at a rate of 1C, which means using charge current equal to the battery capacity.
This isn’t as confusing as it might seem at first. To charge a 4S 1500mAh LiPo battery at 1C, the charging current should also be no more than 1500mAh, or 1.5A. You’ll usually see the mAh capacity of a LiPo battery listed on its label. Just divide that number by 1000 to get the 1C charge rate for the battery in amp-hours. The 1C charge rate for a 5000mAh LiPo battery is 5A.
For a 5A charge rate, you’ll need a LiPo battery charger with at least 25 watts of power for each LiPo cell being charged. If you have a 2S battery pack, then you’ll need 50W. For a 3S LiPo, make sure the charger can deliver 75W of power to minimize your LiPo battery charge time.
Some LiPo batteries allow a faster 2C or even 5C charge rate. How do you figure the maximum charging current you should use with these? First, multiply the battery’s mAh capacity by the C rating. Then, once again divide by 1000. For a 5000mAh LiPo battery, a 2C charge rate is 10A (which is 5000 times 2, divided by 1000). The 5C charge rate is 25A for a faster LiPo battery charge and to extend the life of the battery as much as possible.
Any charge rate higher than 1C is considered a fast charge. Don’t go above a 1C charge rate unless you’re certain that your LiPo battery can handle higher charge rates. Otherwise, battery damage and fires could occur. With 1C charging, you can normally expect your battery to be charged in about an hour. At 2C, the battery charges twice as fast, so will be ready to use in about 30 minutes. When charging at 4C, your LiPo battery should be ready to go in only 15 minutes. How's that for minimizing battery charge times?
Which LiPo battery charger will be best in the long run?
Think of your LiPo battery charger as an investment in the future. You can get a basic 50 watt charger for about $50 — maybe less, if you’re willing to buy an off-brand charger or a used one. But if you stay in the hobby, over the next few years you’ll almost certainly be getting more remote control cars or RC airplanes and more LiPo batteries. Before long you’ll want a LiPo battery charger with additional features, like the ability to charge several battery packs simultaneously. Spending a little more now for a LiPo battery charger that continues meeting your needs as you gain experience will save you money in the long run.
Here are a few features and capabilities you should look for in a LiPo battery charger that will be useful long-term. First, consider how many cells it can charge. Lower-priced LiPo battery chargers often handle only 2S and 3S batteries. That might suffice for now, but when you move up to 4S and 6S batteries, your “value” charger is obsolete — not such a great value after all.
As mentioned earlier, having a LiPo battery charger than can charge several packs at once is a huge convenience. Eventually you may own models that require more than a single LiPo battery, such as 1/8 scale RC monster trucks. If you’re a parent, your kids might all want to run their RC models at the same time, each needing its own fully charged LiPo battery. Having a LiPo battery charger with multiple charging channels will make charging the large number of batteries you’ll need much simpler and faster.
The wattage of LiPo battery chargers has a pretty big impact on their price. However, getting a charger with a higher wattage will be worth the added cost in the long run. If your budget allows, get a LiPo charger that offers at least 100 watts per channel. 100 watts will maximize the charge speed of 1S, 2S, 3S, and 4S LiPo batteries. When you start using bigger LiPo batteries that have more cells, the higher wattage will still provide fast charging times.
More power, more cells, more channels…there’s no getting around the fact that “more” charger also means more money. But besides the increased usefulness of the higher priced LiPo battery chargers, there’s also this to consider: Higher powered, multi-port chargers also have a good resale value. If you decide to get out of the RC hobby someday, or want to upgrade to an even better battery charger, you’ll have an easier time selling your nice charger and getting at least some of your money back.
Should I choose an AC or a DC LiPo battery charger?
Think carefully about the type of power input your new LiPo battery charger will use — whether AC (Alternating Current) or DC (Direct Current). Especially for RC hobby newcomers, AC input might be the easiest to use. You just plug your LiPo battery charger directly into a normal household outlet.
DC LiPo chargers, on the other hand, require a separate power supply, which increases the total cost. What offsets this disadvantage is the convenience of being able to take your DC LiPo battery charger outdoors and use it at the track or flying site, where you may not always have access to an AC outlet. You don’t have to go home when you’ve run out of charged LiPo batteries. Simply connect your DC charger to your automobile battery and recharge your drained LiPo batteries on the spot. Many RC airfields even have solar panels with a battery ready for you to connect to your DC LiPo battery charger.
AC chargers typically produce lower power due to their built-in power supply, which is not always the most powerful. When used with a good-quality external power supply, DC chargers generally beat the performance of their AC counterparts. LiPo battery chargers are available that offer both AC and DC input options if you want maximum versatility.
Smart LiPo Battery Charging and Charge Modes
So you’ve narrowed down your choices to the LiPo battery chargers that are compatible with your batteries and that have the most essential features. Now you can start weighing the benefits of other possible options and capabilities. The options you select will determine what functions your charger can perform besides simply charging your batteries.
Because of their power and versatility, “smart” programmable LiPo battery chargers like the Spektrum S2200 G2 AC 2x200W Smart Charger are today’s industry standard. They go beyond the basic functionality of non-programmable chargers and include important safety features, perfect for beginners or experienced RC hobbyists who charge batteries often.
Smart LiPo battery chargers let you customize parameters such as charging current, voltage, and cell count. They have large, easy-to-read displays that show the charging progress, battery voltage, and charging current in real time. Smart chargers also offer discharging and storage charging capabilities to help keep your LiPo batteries at peak performance.
Three useful operating modes offered by smart LiPo battery chargers are Balance Charge, Discharge, and Storage Charge. There are others, but these three are probably the most essential.
Balance Charge Mode
Using the balance charge mode of a LiPo battery charger is the safest way to charge your LiPo batteries. The charger reads the voltages of all individual cells in the battery pack, and then automatically balances the voltages during the charge cycle. This helps to maximize the capacity and lifespan of the battery.
Discharge Mode
The Discharge mode of a LiPo battery charger is used to drain the battery of its stored energy. This process can be used for a variety of purposes, including to condition or balance the cells for optimal performance. It’s also advisable to discharge a LiPo battery before storing it for an extended time. Doing so helps prevent permanent pack damage and reduced capacity.
Storage Charge
In Storage Charge mode, a LiPo battery charger will charge or discharge a battery until the voltage in each cell reaches 3.85V, making it safe for storage.
Other Smart Charging Modes
As mentioned earlier in this article, fast charging is not considered safe for LiPo batteries due to the potential for overcharging. Still, some smart LiPo battery chargers do include a Fast Charge mode. This mode charges LiPo batteries more quickly because it doesn’t monitor and balance the individual cell voltages. It should be used only if you know what you’re doing.
Smart LiPo battery chargers may also include a Trickle Charge mode. Batteries that are unused for a long period can self-discharge, possibly leaving the voltage in some cells — or the entire battery — too low for a charger to detect. Trickle charge mode slowly feeds current into dead cells, hopefully reviving the battery.
Depending on how much you want to spend, your LiPo battery charger can do much more than keep you racing or flying. It can provide critical information about your batteries’ health, and help you get the best performance out of your RC model by keeping your LiPo batteries in the very best condition. Choose your charger wisely and enjoy your hobby to the fullest!
Words by Wally Armstrong
Wally has been writing about the RC hobby since 1987, when he was hired by Hobbico as a Copywriter after completing his master’s degree in English in 1983 and teaching for several years. He managed the Hobbico copywriting team until 2018, when Horizon Hobby purchased the company and brought him on board as a Senior Copywriter. Wally especially enjoys getting a first look at new Horizon RC products from the Product Development teams – and having the privilege of sharing details about their innovations with RC hobby customers.
