Voltage to change batteries

[Togomi]

Hi,

 

Which is the minimum voltage to change the batteries in an active bass if it works at 18V?

It's Fender Precision American Elite.

 

I forgot to check them and yerterday I had to change to passive.

I've checked batteries today and they have 10,42V. Too low.

 

One IA says that it works well till 12-14V.

I would like to check in order to avoid what happened yesterday.

 

I've had to open back tap. Is there any way to check it without opening the back tap?

 

Thanks in advance

 

[HeadlessBassist]

Usually you can tell when they're going, as your signal starts to aurally disappear through several frequencies. Some instruments emit a high pitched whine when the batteries are getting low, but not usually Fenders. How long have they been in the bass / how long on average is it plugged in? I usually habitually change the batteries in my active basses annually, and I never leave the cable plugged in when I'm not using the bass, as I don't want to get caught short on a professional engagement.

 

Nine volt batteries usually stay at 9 for a very long time. I'd say that yes, 12-14V would be the minimum for an 18V preamp to run at maximum efficiency.

[Hellzero]

It all depends on the opamp used, some will still work with very low voltage...

[Woodinblack]

9V batteries stay higher than 9v most of their life. if I was measuring a battery to see if it was good, and it was a normal PP3, If I measured it and it was below 9v I would throw it away.