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JohnJL JohnJL is offline
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Join Date: Jan 2005
Location: Toronto, Ontario
Posts: 4,767
Voltage fluctuations - Megasquirt and Lipo battery

I am finishing up a megasquirt installation on a 3l and am seeing weird voltage fluctuations in my logs. I am working with a tuner remotely and he noticed this before me. I am not sure if it is effecting the MS corrections but in any case it seems something that should be corrected?

I am using a batterytender LiPo battery, and the megasquirt is grounded directly to the battery. It was grounded through the chassis previously but this change did not fix the issue.



Here is a log of a cold warmup. I have circled the voltage fluctuations in a white oval. Voltage swings from 13.8 to 12.4 and back again continuously. The alternator is a newish Valeo with internal regulator. It has maybe 5,000 miles on it without issue.

I wonder if the lightweight battery doesnt act like a voltage buffer, I thought I heard normally batteries also serve to level out voltage fluctuations. Or a bad altertator regulator? Something else?

Appreciate any help,

John
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Old 05-27-2017, 01:15 PM
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