Why Do Some Bass Guitars Have Batteries?

People who are new to the bass may have come across several basses on the market that uses batteries. These are known as “active basses,” and the batteries involved in these serve an excellent and practical purpose. In this article, you’ll learn exactly the significance of the battery and why it’s used in so many basses out there.

Why Do Active Basses Use Batteries?

In contrast to passive basses, which do not use batteries, active basses use batteries to power up an onboard preamp that also sometimes come with built-in EQs. The active preamp is designed to give you a stronger output signal, and the EQ will allow for greater control over your tone’s frequencies.

In most cases, active basses and their preamp will be powered up by a 9V battery to provide their benefits.


The Signs of A Dying Battery In A Bass

Active bass preamps and EQ are fantastic, but over time, your battery will inevitably start to get drained as you get a lot of playtime with your bass. So, it’s possible that one day you could be playing your active bass, but things don’t seem right – it doesn’t sound as good as it did the other day.

While it’s a very gradual process, it does reach a point where it becomes noticeable. A lot of beginners will worry that their instrument or amplifier has malfunctioned somehow when in reality, the battery is dying.

Once your active bass’s battery gets too drained, it may show these primary symptoms:

  • Crackling/unwanted distortion
  • Weak signal 
  • Low volume

Luckily, it’s a pretty easy fix once you notice these signs of a drained or dead battery in your bass guitar! 

A small pack of 9V batteries isn’t too expensive, and the majority of active basses have a small battery compartment in the back that houses it. However, sometimes, it may also be included in the cavity with the other electronics. 

Either way, just unscrew or pop open the cover, replace the battery, and you’re good to go! 

Also, some active basses have the option for you to switch to passive mode, just in case you’re in a place where you don’t have an extra battery handy or can’t get to a store. However, if I were you, I’d keep a spare nearby in your case or gig bag so you can continue to take advantage of the benefits of the active preamp and EQ.

How Often Should You Replace A Battery In Your Bass?

With regular use, you should replace the battery in an active bass every 4 to 6 months. 

Although batteries are small, as you can see, you still get a lot of mileage out of them in your bass. 

In fact, you can potentially get an entire year of your battery if you take some simple precautions.

One of the best tips to increase your battery’s longevity is to unplug your bass guitar when you’re not playing it. Read on ahead to learn more about this.


Does Leaving Your Active Bass Plugged In Drain The Battery?

Even though you’re not playing it at the moment, if you leave your active bass plugged in, it can absolutely drain your battery.

By having a cable in the input jack, you are activating the preamp’s circuit, regardless of what’s happening on the other end of the cable. Your amp could be turned off, or you could be disconnected from it, and the battery will still drain over time.

So, if you keep a cable plugged into your bass while you’re away from it, that’s hours upon hours of your preamp drawing power from the battery. 

Naturally, that means less playtime from it, and you’ll have to replace it much sooner than later.

Therefore, please do yourself a big favor and ensure that your active bass is unplugged when you’re done using it. You’ll get a lot more playtime from your battery and save money too.

Not only that, it’s still a good habit to develop to prevent your cables or input jack from getting any damage, which is even more inconvenient!



If you’ve been looking around at bass guitars and noticed or read that some of them use batteries, hopefully, this article has answered your questions if you were curious as to why they do.

Active basses have great features, and since you won’t need to replace the battery all that frequently (provided you keep it unplugged), it’s not that big of an inconvenience, especially when considering the months of enjoyment you can get from having a powered-up active bass.

Passive basses are fantastic too, but since they don’t use batteries nor have a preamp and EQ, they take some extra gear, like an external preamp, to get these benefits that were discussed in this article. 

So, that’s also something to think about if you’re trying to choose between an active vs. passive bass.

That being said, by being informed about what you get out of a battery, you can decide for yourself if having active electronics is something you absolutely need in your bass.