Everyone has waded through the pros and cons of the MRC 969. Here is the review done on it at the Battery Clinic. Take it for what its worth.

Model Rectifier Super Brain 969
Reviewer: C. Scholefield – Red’s R/C Battery Clinic.

This charger has an ability to deliver 4.5 amps per channel* when using DC input. The Supplied AC adapter does not have the capability of charging at these rates.
*See operating manual for limits.
You can charge two batteries of different voltages or types simultaneously, or charge one battery while discharging another. The 969 has a variety of charge settings.
· AC/DC delta peak charger. With AC Adapter combine charge current cannot be greater than 5 amps.
· Dual independent outputs for added versatility. Discharge on channel A only.
· LCD screen shows: battery voltage, charge rate, peak threshold, capacity, number of cells in pack & elapsed time. Screen may be toggled between channels.
· Charges NiCd, NiMH, Li & Pb batteries. WARNING – Lithium charging is uncontrolled constant current – NO VOLTAGE LIMIT – Unattended charging of lithium battery can result in explosion and/or fire!
·Lead Acid charging is also constant current with no voltage clamp. Charging rates must be no greater than C/20 if the charger is operated unattended or the battery can suffer considerable damage.
· For 1~8 cells (Ni-Cd & Ni-MH) Note: Per the instruction manual; to charge 7 or 8 cells a higher voltage than the 12 Volt DC input is required as there is no up converter capability in the charger. The upper voltage limit for charging 7 & 8 cell packs is not specified.
· Selectable charge rate with 0.1 amp increments
· Selectable delta peak voltage thresholds in 5mV increments.
· Selectable maximum Charge Input. Default 1700 mAh – must be reset each time charger is connected to power source if different charge inputs are desired.· Selectable maximum Charge Time. Default 40 minutes – must be reset each time charger is connected to power source if different charge times are desired.
· Cooling fan – automatic.
· 12-bit Analog-to-Digital converter.
· Digital Signal Processing.
· Accuracy of voltage/current settings is adequate for this type of device.

Price $119.95 Discounted to $99.99 includes AC adapter.
The unit appears well constructed in a black metal case. Connections to the power source are via a non standard connector to the charger and alligator clips for connecting to a DC source other than the supplied AC adapter. Connections to the battery are provided by banana jacks for channel A and a pig tail with Tamia type connector for channel B. Note: The unit received for test from an independent source may have had this added.

One must unplug the unit to reset the charge or discharge parameters. The unit defaults to 3.0 amp charge/discharge and must be reset if other rates are desired.

Discharge display is lost if stop button is pressed.

AC Power adapter provided seems to go inactive if it is plugged into the unit at the same time a battery is connected. It resets after some time. The unit also works from a 12-volt DC source.

Other annoying feature is that the defaults that must be reset each time by first disconnecting the power source as well as the battery under test. It terminates charge after 1700 mAh are input or upon peak, whichever occurs first. Likewise it terminates charge after 40 minutes or upon detecting a peak, again which ever occurs first. When the charge current is set to a lower rate the time and charge input must also be changed to accommodate this.

If the power to the MRC 969 is disconnected (or happens to go off when using the AC adapter) the unit puts a load on any battery connected to it such that it discharges the battery and possibly reversing some cells if allowed to continue.
After reading the Safety Cautions and Warnings provided in the front of the Manual one has to ask if this charger is a viable product for the modeler.

SAFETY CAUTIONS & WARNINGS

1. Never leave the charger unattended when in use.

2. Do not connect the unit to the DC power supply while there is a
battery attached to the unit. You should disconnect the battery first
and then connect the unit to DC power supply.

3. Do not leave the battery inside any product while charging.

4. Place the charger and battery on a solid uncarpeted surface with
good ventilation.

5. Do not charge the battery inside the full-size automobile as
damage to interior can result.
6. Battery damage can occur if the charge current (Amps) rate is set
too high. Different capacity batteries may require a higher or lower
charge rate. Follow the “Notes on Charging Batteries” in addition to
battery manufacturer’s instructions.

7. If the battery or the charger becomes extremely hot, immediately
disconnect the charger from the power source and allow the
battery and charger to cool.

8. The charger is designed to charge 1~8 cells nickel cadmium or
nickel metal hydride batteries. It will also charge Lithium, lead-acid/
gel cell batteries. Because of the volatile nature of Lithium
batteries, great care must be taken when charging these cells. If
improperly or over charged, there is the risk that the battery will
explode or catch fire. Please follow instructions/recommendations
from battery manufacturer when selecting proper charge rate.

9. Discontinue use if charger casing becomes damaged or cracked.

10. Do not use the DC power source of a running full-size automobile
engine. This is the first charger the reviewer has seen that cannot be used to charge batteries on the way to the flying site.
11. Always disconnect charger from the power source and any battery
when not in use.

12. Adult supervision is recommended for ages 12 and under.

13. If at any time the cooling fan should fail, discontinue use and
return for service.

Instruction manual may be seen at: http://www.modelrec.com/resources/ba...69_manual2.pdf

The reviewer cannot recommend this charger for modeling use.