ESP KH-2 Battery Drain

[Elgitaro]

A couple months ago, I purchased an ESP KH-2 from Sweetwater, and I’ve been noticing unusually fast 9V battery drain.

I always unplug the guitar from the output jack when not in use, so the circuit is not left active.

I measured the current draw using a multimeter, and I’m getting about 792 µA (0.79 mA) with a cable plugged in. The guitar has an EMG KH Bone Breaker set. From EMG specs, I understand each pickup typically draws around ~80 µA, so I would expect something closer to ~160–200 µA total.

To verify, I went to Sweetwater HQ and measured another KH-2 — it showed essentially the same current draw (~794 µA).

Despite this, I’m going through batteries very quickly — about 2–3 weeks per battery. I’m using Rechargeable 9V Batteries, 5400mWh.

Given that both guitars show the same current draw, I’m wondering:

• Is ~0.8 mA normal for a KH-2 with Bone Breakers and stock wiring?
• Does anyone else with this setup see similar battery life?
• Or is there something I might be overlooking?

 

[Matt Liebenau]

Is it still drawing power with the cable unplugged? If so check the output jack wiring. The black wire from the battery connector should go to the ring terminal of the output jack and ground should be on the sleeve terminal. If that’s good check to make sure the black wire from the battery isn’t touching a ground point or the shielding with a bare wire. It just takes a stray strand or two to make the circuit.

 

[ardgedee]

I’m using Rechargeable 9V Batteries, 5400mWh.

That might be your problem. How long does a standard nonrechargeable alkaline last?

 

[Jerry Catanescu]

As suggested in post #2, it really looks like your instrument stays on even when unplugged. Either they reversed the jack sleeve and ground wires, or there's a short somewhere from battery negative to ground

 

[Elgitaro]

That might be your problem. How long does a standard nonrechargeable alkaline last?

The same as rechargeables.

 

[Elgitaro]

As suggested in post #2, it really looks like your instrument stays on even when unplugged. Either they reversed the jack sleeve and ground wires, or there's a short somewhere from battery negative to ground

This really makes sense to me.

 

[Elgitaro]

I measured the current drain when the cable is unplugged. I read the same value! I think the circuitry stays on all the time. Something is wrong with the wiring or components. I sent an email to the dealer to claim my warranty. Let's see how they will respond.

 

[Matt Liebenau]

It’s most likely an easy fix but if the bass is still under warranty then definitely do that. Let us know what happens and what the issue is.

 

[Jerry Catanescu]

If ESP had fitted something like my battery indicator, they would have caught this at the factory. Just saying. I still can't believe most makers of active instruments don't find it necessary to include some sort of power on/low battery indicator. Like... Hello! It's kind of an obvious need.

 

[Elgitaro]

It’s most likely an easy fix but if the bass is still under warranty then definitely do that. Let us know what happens and what the issue is.

Will let you know for sure. Just a small clarification, it is an ESP KH-2 electric guitar, not bass.

 

[Elgitaro]

Ok

It’s most likely an easy fix but if the bass is still under warranty then definitely do that. Let us know what happens and what the issue is.

Ok, I took it to a local shop to have them diagnose and fix the issue. It has been 3 days and I've never heard anything from them. I called them today. The guy on the phone said that the guitar is ready and that they are sorry that they have not called me I went to the shop to pick it up. The guy who "repaired" my guitar said that he opened the wiring cavity and found that some cables were not inserted fully. I asked him if he measured any current being drained from the battery. He said he did not, he just left the guitar 1 day with batteries plugged and the guitar is working. He said "$40 please".
I came home, measured the current drain without the cable plugged in. Guess what! Still draining current! The shop did nothing!

I decided to take it to my own hands and work with Claude AI! In the image below there is a black wire coming from the battery negative, where the left red arrow is pointing. The right red arrow pointing is the other end going to the output jack. That wire was stuck underneath the tone knob!!! The tone knob was literally screwed on top that black wire sandwiching it! Nice job ESP! I took out the tone knob and freed that black wire. After that, I also took out the jack. Did a continuity test from battery negative to guitar sleeve/ground there was no beep!!! Before it was beeping. I measured the current drain again and it was zero when the cable was unplugged. Issue resolved! I can't believe that I purchased a faulty signature guitar with that price tag.

This is a quote from Claude AI

A $5,700 instrument should be flawless out of the box — the quality control expectations at that price point are non-negotiable.

What makes it worse is the chain of failures here:

• ESP's factory shipped it with a trapped wire causing a permanent battery drain
• The local shop you paid didn't even correctly diagnose or fix anything
• You ended up doing the entire diagnosis yourself, methodically and correctly, over multiple sessions

 

[Matt Liebenau]

Ok

Ok, I took it to a local shop to have them diagnose and fix the issue. It has been 3 days and I've never heard anything from them. I called them today. The guy on the phone said that the guitar is ready and that they are sorry that they have not called me I went to the shop to pick it up. The guy who "repaired" my guitar said that he opened the wiring cavity and found that some cables were not inserted fully. I asked him if he measured any current being drained from the battery. He said he did not, he just left the guitar 1 day with batteries plugged and the guitar is working. He said "$40 please".
I came home, measured the current drain without the cable plugged in. Guess what! Still draining current! The shop did nothing!

I decided to take it to my own hands and work with Claude AI! In the image below there is a black wire coming from the battery negative, where the left red arrow is pointing. The right red arrow pointing is the other end going to the output jack. That wire was stuck underneath the tone knob!!! The tone knob was literally screwed on top that black wire sandwiching it! Nice job ESP! I took out the tone knob and freed that black wire. After that, I also took out the jack. Did a continuity test from battery negative to guitar sleeve/ground there was no beep!!! Before it was beeping. I measured the current drain again and it was zero when the cable was unplugged. Issue resolved! I can't believe that I purchased a faulty signature guitar with that price tag.

This is a quote from Claude AI

A $5,700 instrument should be flawless out of the box — the quality control expectations at that price point are non-negotiable.

What makes it worse is the chain of failures here:

• ESP's factory shipped it with a trapped wire causing a permanent battery drain
• The local shop you paid didn't even correctly diagnose or fix anything
• You ended up doing the entire diagnosis yourself, methodically and correctly, over multiple sessions

View attachment 7490459

I’m glad you got it sorted out. On ESP’s end I’d guess that QC just makes sure the bass plays and the controls work. I’d be quite surprised if any manufacturer checks for battery draw with the plug out. That, unfortunately, seems to fall in the “stuff happens” category. As for the shop, dunno. If it was on my bench and you had told me all that or I read this thread I would have been checking all that before I said it was fixed.

One other thing, you might give that wire a visual inspection to see if the insulation appears damaged. It could still end up touching ground somewhere. I’m guessing you don’t want to solder in another wire so if it appears damaged you can carefully wrap it in a little electrical tape.