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BrianG · 10:46 AM

You should be able to get 7 wires there. Just strip them individually and then twist the ends together tightly. Then tin the end so it stays together. Cut the very tip so the tinned part ends nice and flat. Now solder it to the Deans.

When you have the whole thing together, charge your biggest pack at the highest safe recommended current. This will put the highest strain on the power supply. If all is well, the charger will simply charge the batteries with no issues. However, if the charger shuts off, or displays some kind of error message along the lines of "input voltage is low", then a little more modding is necessary, but not difficult or expensive. To make sure this is the case, get a voltage measurement of the 12v output of the power supply while the charger is running hard. Chances are that the 12v line will be near or below 11v.

As others have said previously, resistors can be added to the other unused lines to cause the regulator to work better, thereby making the 12v line more stable even under heavy load. As far as what resistor to use: RadioShack carries two resistor values that will work well while drawing the right amount of current. A 10 Ohm, 10W, and a 1 ohm, 10W.

For the 5v line, you have two ideal choices using these RadioShack resistors.

1) You can put two 10 ohm resistors in parallel for a 5 ohm total load. This will draw 1A from the 5v line and dissipate 5W. Using two 10 Watt resistors should be perfectly fine and should get just a tiny bit warm.

2) You can put two 1 ohm resistors in series for a 2 ohm load. This will draw 2.5A from the 5v line and dissipate 12.5 watts. Using two 10 Watt resistors should be ok, but they will most likely get quite warm after a while. However, since this option draws more current, the regulator might be a little more accurate and cause the 12v line to stay nearer to 12v.

For the 3.3v line, you can put two 1 ohm resistors in series for a 2 ohm load. This will draw 1.65A from the 3.3v line and dissipate around 5.5 watts. Using two 10W resistors should be perfectly fine and should get just a tiny bit warm.

These arrangements work well since those resistors come in packs of two. Refer to the diagram for examples of these configurations.

The idea in both cases is to draw between 1A and 3A to properly load each output. 2A to 3A is better, but may be difficult to find cheap resistors that will dissipate the power. While easily done, you have to make sure that you do not exceed the power ratings of the resistors or they will burn up.

Formulas:

resistance = output_voltage / desired_current
resistor_power = (output_voltage * desired current) * 2

Other places to get power resistors: Parts Express, All Electronics, etc.

	(#14)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	09.09.2006, 09:16 PM You should be able to get 7 wires there. Just strip them individually and then twist the ends together tightly. Then tin the end so it stays together. Cut the very tip so the tinned part ends nice and flat. Now solder it to the Deans. When you have the whole thing together, charge your biggest pack at the highest safe recommended current. This will put the highest strain on the power supply. If all is well, the charger will simply charge the batteries with no issues. However, if the charger shuts off, or displays some kind of error message along the lines of "input voltage is low", then a little more modding is necessary, but not difficult or expensive. To make sure this is the case, get a voltage measurement of the 12v output of the power supply while the charger is running hard. Chances are that the 12v line will be near or below 11v. As others have said previously, resistors can be added to the other unused lines to cause the regulator to work better, thereby making the 12v line more stable even under heavy load. As far as what resistor to use: RadioShack carries two resistor values that will work well while drawing the right amount of current. A 10 Ohm, 10W, and a 1 ohm, 10W. For the 5v line, you have two ideal choices using these RadioShack resistors. 1) You can put two 10 ohm resistors in parallel for a 5 ohm total load. This will draw 1A from the 5v line and dissipate 5W. Using two 10 Watt resistors should be perfectly fine and should get just a tiny bit warm. 2) You can put two 1 ohm resistors in series for a 2 ohm load. This will draw 2.5A from the 5v line and dissipate 12.5 watts. Using two 10 Watt resistors should be ok, but they will most likely get quite warm after a while. However, since this option draws more current, the regulator might be a little more accurate and cause the 12v line to stay nearer to 12v. For the 3.3v line, you can put two 1 ohm resistors in series for a 2 ohm load. This will draw 1.65A from the 3.3v line and dissipate around 5.5 watts. Using two 10W resistors should be perfectly fine and should get just a tiny bit warm. These arrangements work well since those resistors come in packs of two. Refer to the diagram for examples of these configurations. The idea in both cases is to draw between 1A and 3A to properly load each output. 2A to 3A is better, but may be difficult to find cheap resistors that will dissipate the power. While easily done, you have to make sure that you do not exceed the power ratings of the resistors or they will burn up. Formulas: resistance = output_voltage / desired_current resistor_power = (output_voltage * desired current) * 2 Other places to get power resistors: Parts Express, All Electronics, etc. Last edited by BrianG; 07.14.2008 at 10:46 AM.