Long known for affordable, high-quality servos and radio systems, Hitec has also added a complete line of chargers during the last several years. With offerings suitable for everyone from first-time modelers to lifelong enthusiasts, Hitec is sure to have a charger to suit your needs.
At the top of the list is the new H4 Four-Port Multi-Charger, targeted to the prolific electric flier or anyone else who wants to treat his or her batteries with the respect they deserve. The H4 is not just a charger—it is a professional grade, battery management system tailored to today’s RC hobbyist.
A Quick Look
The H4 is actually four balancing chargers wrapped in a single durable aluminum case. Each separate 120-watt output channel is capable of charging and discharging the six different battery chemistries we commonly use with our models: LiPo, Li-Ion, LiFe, NiCd, NiMH, and Lead Acid. Additionally, each channel has its own dedicated balancing port to ensure maximum performance and safety when using Lithium-based packs.
The H4 incorporates a large, variable contrast LCD display surrounded by four channel-selection buttons and six buttons for programming and operation. Along the sides are the connectors for each output port. These include a pair of bullet connectors for the main power leads as well as a seven-pin balancing connector and a port for optional temperature sensors.
The left side also has a dedicated port to update the H4’s firmware using Hitec’s HPP-22 programming interface. The back of the case has two cooling fans as well as the leads for connecting to your DC power supply.
Bells and Whistles
Today’s market demands flexibility and capability right out of the box, and the H4 shines on both fronts. Before we get to the included cables and adapters, let’s first touch on two exciting features of the H4.
Perhaps the biggest feature is the incorporation of the Hitec Channel Bridge. This allows you to combine two adjacent charge ports in parallel, doubling your current capacity to a full 240 watts of charging power and 20 watts discharge. You also have the option to bridge channel pairs on both sides, or just one, as your charging needs dictate.
Another great feature of the H4 is its battery discard mode. Although other Lithium chargers may offer a storage charge setting, the H4 also allows you to safely bring a battery down to near zero voltage for safe disposal. As far as I know, this is an industry first and saves hassling with multiday soaks in buckets of saltwater. We will look at both of these in more detail.
The H4 power input leads are made from high-quality flexible wire and equipped with 4mm male bullet connectors. These connectors will mate with most AC/DC power supplies today. For charging in the field, Hitec also includes terminal clips with integral 4mm female connectors for attaching the H4 directly to a car battery.
Hitec thoughtfully packages a number of cables and adapters with the H4 to get you started. These cables and more are also available separately so you can mix and match as needed. In addition to the power lead battery clamps, the H4 comes with four charge cables, each equipped with a different, common connector. These include a female servo connector for receiver batteries, as well as leads with two-pin Deans Ultra, Tamiya, and Traxxas connectors.
Hitec also includes three adapters to accommodate the most common balancing connectors in use. With this collection of cables you will most likely be able to use the H4 right out of the box, and know exactly what you will want to order to service your entire battery collection. Additional optional balancing adapters, charge connectors, and temperature probes are also available.
There is no power switch on the H4, so as soon as you connect it to a power source it comes to life. You can connect any needed charge and balancing leads before or after powering up. When the charger is active, connect your battery and select the appropriate channel button to program the charger.
I recommend that you open the manual and walk through a few sample setups for each battery’s chemistry. The H4 menu architecture is readily accessible, but many of us have found frustration in the past trying to figure out how to think like a programmer.
The H4 offers welcome relief from that situation. Quite simply, the H4 interface is easy to use and works in a way that makes sense. It only took me a few moments with the H4 and manual together to realize that using this charger would be a joy, despite its extensive capabilities.
When charging a Lithium battery, the H4 calculates the cell count based on input from the balancing port and compares it with your settings. This allows a final opportunity for you to confirm your settings before you begin the charge.
This checking feature can also be disabled, so that the charge/discharge cycle begins with your initial press of the start/enter button. Even with the manual confirmation step disabled, the H4 will immediately discontinue the operation and alert you to reconfigure your settings if the numbers don’t add up.
The H4 allows you to charge Lithium batteries in both normal and balance modes. With individual balance circuitry for each port, I can’t imagine why you wouldn’t want to balance charge your packs on every cycle.
Each channel can also be set up to save 10 different charging profiles so that you can easily access previous settings for your most commonly used batteries.
Nickel Peak Detection
The H4 is not just a Lithium battery charger. The same flexibility and sophistication is also available for the NiCd and NiMH batteries still commonly used for transmitter and receiver batteries for larger glow and gas models and cordless starters.
The H4 is designed to charge these nickel-based batteries using a sophisticated peak detection circuitry. In addition to the stock default settings, you can also customize the trigger for the end-of-charge point. You can increase the peak-sensing sensitivity, turn it off completely, or set the trigger point based on a variable Delta Peak voltage from 0-20 millivolts at 5 millivolts per cell.
Most of us will find the default settings well suited to our needs, while those needing maximum flexibility will find it available with the H4.
As previously mentioned, the H4 is capable of charging four different packs at the same time. The four output ports/channels are completely independent unless you have the Channel Bridge in play, so you can charge four separate chemistries just as easily as identical packs.
The detailed LCD screen gives continuously updated information including charge/discharge voltage, current, total charge percentage and mAh returned to the pack for the active channel. To switch the data display to another channel, simply press the channel select button for the channel you want to monitor or program next.
There is a red LED next to each channel selector button that glows to indicate when that channel is in use. If you are charging more than one pack at a time, the LED that is not flashing indicates the channel for which you have active control with the programming buttons. Flashing LEDs indicate any other channels in use. Simply press the channel button for any active channel to monitor or program that charge port.
There is also a surveillance monitor mode that shows the chemistry, current, and voltage for each channel simultaneously. This is a great way to maintain an overview of your charging session and is easily accessed using the up and down menu buttons.
Hitec’s innovative Channel Bridge function allows you to effectively double the capability of your charger. In simple terms, the bridge function lets you connect two output ports in parallel, combining the charge and discharge capacities of the two channels. Thus, you can team up two 8-amp, 120-watt outputs to provide a single output port per side with a maximum charge rating of 16 amps or 240 watts. This works out to nearly 15 amps for a 4S pack or 10 amps for a 6S pack. With modern battery chemistries now capable of charging rates over 1C, this is a welcome feature.
All good things must come to an end, and when your battery has outlived its usefulness, an appropriate disposal plan is necessary. You can’t just toss a battery in the trash and hope it doesn’t short out against something. Although the basic chemistry of a LiPo battery does not represent the same environmental hazard as nickel-based cells, you should ensure that your battery is completely discharged before placing it in the trash.
The traditionally accepted method of discharging a Lithium battery has been to soak it in a salt solution for several days until it has self-discharged to zero volts. The H4 offers a more sophisticated option with its discard mode. Accessed through the system menu, the discard mode allows you to fully discharge a LiPo battery, thus neutralizing any potential energy left in the pack.
This discard cycle will almost certainly render a battery unrecoverable, so it must be used with caution. Fortunately, although readily accessible, it is in the system menu and it is unlikely to be accessed by accident.
After discharge, the resting voltage of the pack may rebound some, but once a load is applied, the voltage will again drop to safe levels for disposal. Hitec recommends use of a fireproof container or LiPo bag whenever charging or discharging Lithium batteries and I concur, especially when discharging with the Discard Mode.
The H4 Smart Charger has several additional features that enhance its operation. Both input and output are protected from reverse polarity and the output is also protected from short circuits.
The H4 also monitors the input voltage, preventing operation if it gets out of range. For instance, the charger will shut down if you discharge your 12-volt source battery too far. On the ergonomic front, a support bar clips into the back of the charger, angling it for an easy view of the screen.
Everything about Hitec’s H4 Smart Charger—from the solid aluminum case to the logical interface, programming ease, and reliable results—speaks to its high quality. The exceptional flexibility, capacity, and easy handling join forces to make this a charger well suited for today’s dedicated enthusiast.
(Data represents the capability of individual charger ports except for input power, dimensions, and weight)
Input voltage range: 11-18 volts direct current (VDC) with 30- to 40-amp capacity
Cell count: One to six LiPo/Li-Ion/LiFe cells; one to fifteen NiCd/NiMH cells; one to twelve Lead-Acid cells
Charge current range: 0.1 to 8.0 amps (120 watts maximum, 240 watts with Channel Bridge)
Discharge current range: 0.1 to 2.0 amps (10 watts maximum, 20 watts with Channel Bridge)
Charge detection: NiCd/NiMH negative Delta Peak method; Lithium and Lead Acid automatic
Lithium balancing current drain: 300 mAh per cell
Dimensions: 8.07 x 6.42 x 2.05 inches
Net weight: 2.65 pounds
Street price: $289.99
• Lithium disposal discharge mode.
• Channel Bridge feature.
• Ease of use.
• Flexible programming.
• Abundant information on large display.
• Durable, stylish aluminum case.
• Discharge power limited to 10 watts per channel and 20 watts with Channel Bridge.