Super brain

PRODUCT REVIEW

The only charger you'll ever need

Decades of electronic expertise have gone Into the development and production of MRC's battery chargers. The company's latest model, the Super Brain 959, is a highly sophisticated delta-peak-detect charger with special patented microprocessor circuitry. Attractively priced at under $70, this state-of-the-art unit will be welcome news for RC airplane, boat and car enthusiasts.

The 959 can be powered by either 115 volts of AC house current or by a 12V DC (car) battery, and it can charge 3- to 8-cell Ni-Cd or NiMH battery packs. When used with an optional adapter (available free from MRC), it can also charge a single cell, such as those used with glow drivers.

You can select seven discrete charge currents: 0.5, 1, 1.5, 3, 3.5, 4 and 4.5 amps. Realistically, this range of currents will allow you to charge battery cells with capacities of from 150mAh up to approximately 3,000mAh. In addition, you can select six different delta-- peak-voltage thresholds to tailor the cutoff point for specific cell types (no worries about premature peak detection). A 1 1/2 x 5/8-inch LCD screen shows you five important pieces of information: battery status (a small icon indicates the amount of charge in the battery pack), battery voltage (V) while under charge, charge current (A), charging time (in minutes) and delta-- peak-voltage threshold in millivolts (mV).

The 959 is very compact, so it's easy to transport. Three sets of cables exit the plastic case. A 60-inch zip cord provides 115 volts of AC power to operate the charger at home or during indoor flying. An 18-inch cable terminating in two alligator clips is intended to draw power from a 12V DC battery. The 12-inch-long output lead to the battery being charged terminates in a Tamiya-type connector. It is quite easy to make an adapter with the mating half of the Tamiya on one end and your choice of another type of connector, such as an Anderson or Deans, on the other.

ON THE BENCH

I used the 959 exclusively for several weeks, and it worked reliably and quite well throughout all of my testing with a wide variety of battery packs. Using this charger is very simple. The instructions are brief yet effective.

Begin by powering up the charger either with AC or DC current. Initially, the LCD screen will show zero voltage. Next, attach the battery and note that the LCD screen shows the battery voltage before it begins to charge. The charger default current level is 3 amps; if you wish to select one of the other six charge-current levels, first press "Display" until you see 3 amps. Then press "Select" until the current you want appears on the LCD screen. At that point, press "Start," and a red LED next to the start button will flash. For about 30 to 60 seconds, the charger goes through a self-- diagnostic period, during which it will not accept any other commands. After this, the LED will glow a steady red, and charging will begin. You will note that the display always reverts to the voltage under charge. This will show you when voltage peaks. If you want other information from the LCD screen while the 959 is charging, just press "Display." The unit will cycle from voltage to current, to charge time, delta-peak-- threshold voltage and then back again. In every display item, the battery-status icon appears in the upper left-- hand corner of the LCD screen. This icon appears dear when the battery pack is fully discharged. As the charge builds up in the pack, the icon becomes shaded (black). When the icon is fully shaded, the battery is fully charged-a neat and simple indicator!

When the peak voltage is reached, the 959 cuts itself off and beeps three times. The charger automatically adjusts to a 100mA trickle rate and will remain at that level for 50 minutes, after which the charger turns itself off. During trickle charge, the red LED will blink quickly, and the LCD screen will hold the peak voltage attained at the point of cutoff. This is a good reference point if you keep records on each battery pack. Keep in mind that the display always reverts to the voltage reading. When you select another item, such as charge current, that display stays on for only a few seconds and then returns to "voltage." Also, if you select a charge current other than the 3A default setting, the 959 will stay at that level as long as the charger is hooked up to a power source. When the charger is unplugged, it resets to the 3A current level.

FNAL ANALYSIS

I found the 959 very accurate and repeatable in all of my tests. You must remember that this is not an automatic current-setting charger; you need to set the current level for your particular batteries' rated capacity. On the one hand, if you set the current too low, it will take much longer to reach full charge. On the other hand, if you set it too high, you might damage the battery. Generally speaking, I use the figure of three times the rated capacity for Ni-Cd batteries. If the battery is rated at 1,000mAh (1 amp/hour), I set the charger to 3 amp (3x"C"). If the battery was fully depleted, it would take approximately 20 minutes to reach full charge. For NiMH batteries, I use a more conservative two times the rated battery capacity. So for a 500mAh (0.5 amp/hour) pack, I would set the charger to 1 amp (2x"C"). In that instance, it would take approximately 30 minutes to reach full charge. I made up the chart, "Selecting Charge Current," to help with this. By the way, the 959 is strictly a charger; it does not have any discharge capability.