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Old 03-22-2009, 10:58 PM   #1
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Default Help with MMM?

Hey I can't figure something out I have a savage flux with mmm 2200kv motor and 25v speed control. I use 2 cell lipo's but heres the problem.

After each run one pack is always drained down lower than the other and today one got down dangerously low of not ever being able to use it but the other was well within the safe margin

Anyone got something for me?
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Old 03-22-2009, 11:01 PM   #2
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Originally Posted by moose2851 View Post
Hey I can't figure something out I have a savage flux with mmm 2200kv motor and 25v speed control. I use 2 cell lipo's but heres the problem.

After each run one pack is always drained down lower than the other and today one got down dangerously low of not ever being able to use it but the other was well within the safe margin

Anyone got something for me?
Is the lipo cut off programed into it. Also what batteries are you using?
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Old 03-23-2009, 07:02 AM   #3
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I would say if one pack is lower than the other one it would seem that one pack is not as strong as the other one and is lower voltage when finished. Not sure the speedo would drain one pack more than the other since both packs are working together the way they are hooked up.
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Old 03-23-2009, 08:47 AM   #4
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I am using 2 different sets of packs SMC and Max amps have the same problem with both the lipo cut off is set to 6.5 Hope that helps let me know if there is more I can look into
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Old 03-23-2009, 08:48 AM   #5
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Are the two packs the same capacity? They should be identical or one will drain lower than the other. Do you have them wired in series or parallel? They should be in series meaning that a positive leed from one pack hooks to the other packs negative leed. The other two leeds should be hooked to the speed controller.
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Old 03-23-2009, 08:54 AM   #6
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I am using the same packs 6500mah and a set 4100mah never mixed always together same brand same purchase time same amount of cycles. The speed controlled is factory wired but I checked it is as you say in series. Thanks for the help hoefully we can get to the bottom of this
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Old 03-23-2009, 05:17 PM   #7
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bump
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Old 03-23-2009, 08:38 PM   #8
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I am using the same packs 6500mah and a set 4100mah never mixed always together same brand same purchase time same amount of cycles. The speed controlled is factory wired but I checked it is as you say in series. Thanks for the help hoefully we can get to the bottom of this
I'm a little confused. Do you have two 4100 packs that you use together and two 6500 packs as well or do you use a 4100 and 6500 together during the same run? If you are mixing the 4100 and 6500 together, you should stop. Because they are not the same capacity, you really shouldn't use them together in a 4 cell configuration. The 4100 will run out of power much sooner than the 6500. You could set the lipo cutoff to compensate, but that would be a little risky. On the other hand, if you are using two 4100s and two 6500s together, you shouldn't have an issue. Your lipo voltage cutoff should be set at 12 volts or higher as no single cell should drop below 3.0 volts
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Old 03-23-2009, 10:57 PM   #9
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No I use only the 4100 with the 4100 and 6500 with the 6500. I have never heard of setting the lipo cut off at 12v I was told 6.5 why would I set it so high? Thanks
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Old 03-23-2009, 11:06 PM   #10
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No I use only the 4100 with the 4100 and 6500 with the 6500. I have never heard of setting the lipo cut off at 12v I was told 6.5 why would I set it so high? Thanks
Okay then, I think you might be running your batteries too far down. When you combine two battery packs in series, their voltage is combined. When charged, a two cell battery will provide 8.4 volts; two of them will provide 16.8 volts. For one battery pack (2 cell), you should run it no lower than 6.0 volts. For a two battery packs wired in series, the cutoff voltage will be two times what it is in one pack. This means you should run them no lower than 12 volts when combined into a 4 cell pack.
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