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3s Lipo on Mercury ECU/fuel pump ??

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Old 09-25-2013, 12:41 PM
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turnnburn
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Default 3s Lipo on Mercury ECU/fuel pump ??

I have an old air start Mercury 180. I would prefer to use a lipo for the ECU/fuel pump. 2 cell certainly isn't enough volts and 3 cell Lipo seems like it might be too much. I don't want to burn up the ECU so I have not tried it yet. Is 3s lipo going to be ok ??
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Old 09-25-2013, 02:49 PM
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Don't do it. The old ECU is meant for a 6 cell NiCd/NiMh. Even a 2 cell LiPo will be too much voltage when fully charged.
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Old 09-25-2013, 03:06 PM
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I think I disagree. I just now made two starts on the driveway at home. First one was with the 6 cell NiCad that came with the engine. Then I decided to try a 2 cell lipo. It started and seemed to run just fine. When fully charged the 6 cell NiCad is reading about exactly the same as a freshly charged two cell lipo, both are around 8.3.or 8.4 volts. If anything the NiCad is a little higher than the lipo when fully charged and hot off the charger.

Now I have a new question. My engine is reaching 100% RPM at about 50% or slightly above stick travel. I don't much care for that. Needless to say I want full power at full stick and somewhere around half of full RPM (or better still half of full thrust). Right now my throttle channel is set for 100% in both directions and there is no throttle curve or expo programmed. Imagine I need to cut down the travel in the high throttle direction by approx. one half ??
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Old 09-25-2013, 05:06 PM
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Quote:
Originally Posted by turnnburn View Post
I think I disagree.............
Then why did you ask? That ECU has no provisions for LiPo. If it over disscahrges, it could cause issues to the battery. (or cause a fire)

So... will a 2s LiPo work??? Sure it will. But, it's not right, and really not safe.

As far as your new question......


The early AMT ECU's have to learn the stick, and max RPM pump voltage every time you turn it on. So... after you start it... you have to go to full stick for 6 to 10 seconds before you fly.


If your pre-start "beeps" are telling you that mid stick is full... then adjust the travel volume in the radio. But... I know that 100% ATV will work on JR, Spektrum, and Futaba.

If you have a data terminal... it will tell you the stick %.
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Old 09-25-2013, 06:03 PM
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I asked because I figured a 2 cell lipo with nominal voltage of 7.4v volts was too low and I was fearfull that a 3 cell lipo was too much voltage. I decided it couldn't do any hard to try a 2ell lipo and see if it worked. I did and it seemed to work just fine. That's why I asked. I also the same question posted in the regular jet forum and they seem to think I can 2cell or 3 cell with no issues. I was of the impression that the teaching of the ecu was done before starting the engine, not after. I better go back and read more carefully the instructions, one of us doesn't know what we are talking about and your answer seems to differ from what the other fellows are saying.

Last edited by turnnburn; 09-25-2013 at 06:49 PM.
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Old 09-25-2013, 06:03 PM
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I am using JR 10x. Tx
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