ChadM
Member
I am new to the forum; apologies for taking so long to get here 
I have been searching the forum for internal pictures and/or a schematic of the Estes Pro Series II Launch Controller with no success. I found threads asserting concerns about the use of 3S LiPo batteries attached to the JST connector Estes includes with this launcher (the potential absence of circuit protection leading to catastrophic LiPo failure was a theme). No schematics or internal pics were included in these threads, however.
I thought it might be useful to perform minor surgery on one. The results of said surgery follow.
First, to satisfy the tl;dr users (of which I am often one), the end results of the exploratory surgery, modification(s) and the schematic:
List of modifications:
In order to gain access to the innards, without butchering the screws, you need a tool to unscrew the 'triangle' security screws.
With access gained, you are treated to the creamy center within:
The first observation is the "color polarity" of the outputs is reversed. This is only cosmetic, but is easily fixed, so why not.
There appears to be zero over current protection, so I will add that.
The negative connection on the PCB has somewhat fractured (delaminated). As the return path is through the igniter, there is no compulsory reason to terminate this on the PCB, so I will move the battery return to an off-pcb junction.
In order to accommodate the LiPo and Battery Monitor, it's time to get cutting.
First, the C battery terminals and wiring are removed. C batteries won't fit in the battery compartment after the Battery Monitor is installed, so the motivation to keep the C battery support as a backup as not possible.
Next, the Battery Monitor needs to be inserted through the top panel and the battery compartment, a dremel tool is used.
The Battery Monitor wiring, 3S charging cable, rewired battery return junction and wiring exit are completed next.
Let all of the Permatex Ultrablack dry for 24h.
Finally, connect the Battery Monitor harness to the monitor, roll the temperature cable so it will be sandwiched under the LiPo, install the LiPo (connecting it to the JST and to the 3S charge cable) and re-assemble.
I have been searching the forum for internal pictures and/or a schematic of the Estes Pro Series II Launch Controller with no success. I found threads asserting concerns about the use of 3S LiPo batteries attached to the JST connector Estes includes with this launcher (the potential absence of circuit protection leading to catastrophic LiPo failure was a theme). No schematics or internal pics were included in these threads, however.
I thought it might be useful to perform minor surgery on one. The results of said surgery follow.
First, to satisfy the tl;dr users (of which I am often one), the end results of the exploratory surgery, modification(s) and the schematic:
List of modifications:
- Inline, waterproof fuse to ensure a degree of over-current protection exists
- Externalized 3S balance charger cable to eliminate the need to remove the screws and back-panel to gain access to the LiPo battery
- Battery charge monitor and alarm
- Battery temperature monitor and alarm
- System output voltage monitor and alarm
- Waterproof quick disconnect cable (so the unit and the launch leads can be carried separately)
- Corrected the "color coding/polarity" of the output wires (they were reversed at the factory)
- https://www.amazon.com/gp/product/B0757HBWM2/?tag=skimlinks_replacement-20 (5 Pieces /set Magnetic Triangle Head Screwdriver Bits S2 Steel 1/4 Hex Shank Set)
- https://www.amazon.com/gp/product/B01GYSW84C/?tag=skimlinks_replacement-20 (Apex RC Products JST-XH 3S 6" / 150mm Balance Plug Extension Lead - 5 Pack #1091)
- https://www.amazon.com/gp/product/B01N7CHYCF/?tag=skimlinks_replacement-20 (KUNCAN 2FT SAE to O Ring Terminal Harness Wire 2 Pin Lug Cable, Eyelet Terminal Harness Extension Charge Cord, Quick Disconnect SAE Connection Lead For Motorcycle, Car, Tractor 10A Fuse)
- https://www.amazon.com/gp/product/B01MZZGHNK/?tag=skimlinks_replacement-20 (KUNCAN 25ft Sae to Sae Connector Extension Cable, 16AWG Gauge 2 Pin Wire Harness DC Cord, SAE Connection Lead, Quick Disconnect Cord)
- https://www.amazon.com/gp/product/B07759SLYP/?tag=skimlinks_replacement-20 (Battery Capacity Monitor, DROK 10-100V Programmable Battery Level Voltage Temperature Meter Gauge 12V 24V 36V 48V LCD Display Percentage Indicator Tester Electric Quantity Detector Reader Panel)
- https://www.amazon.com/gp/product/B00MVQ8T6I/?tag=skimlinks_replacement-20 (Turnigy 1000mAh 3S 20C Lipo Pack)
In order to gain access to the innards, without butchering the screws, you need a tool to unscrew the 'triangle' security screws.
With access gained, you are treated to the creamy center within:
The first observation is the "color polarity" of the outputs is reversed. This is only cosmetic, but is easily fixed, so why not.
There appears to be zero over current protection, so I will add that.
The negative connection on the PCB has somewhat fractured (delaminated). As the return path is through the igniter, there is no compulsory reason to terminate this on the PCB, so I will move the battery return to an off-pcb junction.
In order to accommodate the LiPo and Battery Monitor, it's time to get cutting.
First, the C battery terminals and wiring are removed. C batteries won't fit in the battery compartment after the Battery Monitor is installed, so the motivation to keep the C battery support as a backup as not possible.
Next, the Battery Monitor needs to be inserted through the top panel and the battery compartment, a dremel tool is used.
The Battery Monitor wiring, 3S charging cable, rewired battery return junction and wiring exit are completed next.
Let all of the Permatex Ultrablack dry for 24h.
Finally, connect the Battery Monitor harness to the monitor, roll the temperature cable so it will be sandwiched under the LiPo, install the LiPo (connecting it to the JST and to the 3S charge cable) and re-assemble.
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