Battery voltage read issue

[spyro512]

Hi,

Guess I'm a noob on electric systems but I'm having a problem:

I'm feeding the circuit with a 16.2V LiPO battery. Everything works fine until I start the engine, when the ECU Manager stops reading ~16V and reads ~12.5V.

Strangely If I put a tester between the + and - of the LiPO battery it reads 16V.

So the thing is, the tester reads 16V and the ECU Manager around 13V when the engine is in idle. Is this normal?

Thanks!

[Holmz]

What is the VOM reading at the ECU?
(The ECU cannot measure the Volt reading at the battery.)

It is probably normal with some ground or +V resistance.
Not ideal though by any measure.

You could also measure current between the ECU and ground or ECU and +V.

[David Ferguson]

Based on the fact that you can't setup the BatV warn hi value to anything greater than 15V, I would say that the ECU probably considers any value greater than 15V as out of range and uses a default of 13V.

Normally the upper and lower warning values are set in Adjust->Sensor Setup->Input Setup ("Other" tab for Battery Voltage). The Battery Voltage channel doesn't provide the opportunity for you to set a default value, or select a warn hi value above 15V.

[baselkwt]

I run 2 16.8v lipo batteries on my bike, i see 16.5v with everything on, engine stopped, fuel pump off.

and 16v with engine idling. and no less than 14.8v volts at high rpm (around 12k) with all nitrous solenoids on, after the bike has done a burnout and idled for a short while. no charging system (obviously)

check the resistance between your battery +ve and the ecu connector,
and check the resistance between ecu ground terminals and battery -ve

[spyro512]

The cause of this was finally bad ground set up.

Thank you all