Join Date: Dec 2000
Location: Morgan Hill, CA
Re: Emg Pickups
Can I use multiple batteries?
Yes. If you've got room for multiple batteries in your guitar, you can use two batteries wired in series to power your onboard circuitry at 18 volts. The output level will not appreciably increase, but you'll have increased headroom and crisper transients. This is especially useful for percussive/slap bass styles where you can generate enormous instantaneous power levels across the entire frequency spectrum.
You can also wire two batteries in parallel to provide a regular 9 volt supply but with much longer lifespan between battery changes.
Although most of our products are rated for 27 volts, we recommend a maximum of 18 volts. The additional benefits of 27 vs. 18 volts are negligible.
How long does the battery last?
All EMG pickups and EQ systems are designed for extremely low current drain. In addition, the pickup jack included with all models has a switch that disconnects the battery when the guitar is not plugged in. To maximize battery life, you should always unplug your guitar when it's not in use.
The Specs Page includes current requirements and estimated battery life for each model. Generally, each pickup requires about 80 microamps (uA), except for the Vintage Series pickups which require 220 uA each. EQ circuit requirements vary widely but are higher than pickups.
For your reference, a standard 9 volt alkaline battery provides 580 milliAmpHours (mAh) of power. That means that it will provide 580 milliAmps for 1 hour or 1 milliamp for 580 hours. There are 1000 uA per mA. You can figure the approximate battery life of any setup by adding up the individual power requirements, then dividing 580,000 by this total. Here's an example:
1 - EMG-81 = 80 uA
2 - EMG-SV = 220 uA*2 = 440 uA
1 - EXG = 410 uA
Total required = 930 uA
Total life = 580,000 uAh/
930 uA = 623 hours
If you left your guitar plugged in day and night, the battery should still last a month. Under normal playing conditions, you would probably be looking at changing the battery twice a year. Of course, you should treat these numbers conservatively and not try to drain every last uA out!