Plug in to recharge: Is there a way?

SolidFooting · #1 06-06-2011, 09:59 PM

Hi. I'm new here, and I admit this is a rather unorthodox question, but I was wondering if anyone knew of a good way to do this.

My wife plays a Squier Bronco bass. I've replaced most of the components, and even wired in an onboard amp that serves well as a preamp when plugged into something. It has a speaker too.

I did all this because my wife isn't one to do a lot of work in order to get set up. I try to make everything as mindless as possible.

The built-in amp is 2w. It eats batteries real quick. It's powered by a 9v battery, but I know it can handle up to 18v. Here are a couple of things I know I could do:

1. Buy rechargeable batteries.
2. Wire the guitar to receive power through a stereo cord and an AC adapter.
3. Wire two or more batteries in parallel.

But what I'd REALLY like to do is permanently install a battery charger, so it will be like her cell phone or laptop. She can plug it in at night and leave it alone until she's ready for it. (Again, it has to be fairly mindless. I need it to be something that won't make a battery explode.)

I've thought about trying to use a cell phone battery, but most are only about 3.7v. I've also thought about trying to install a laptop battery, but they're huge, and the bass is only about 1.5" thick (38mm?). Not sure how they work either. Something like an RC battery pack would work, but I'm not sure how to wire it to an amp and a charger output at the same time without causing a nuclear explosion or something.

Anybody know how to permanently install some sort of charger that wouldn't require any switches or anything, kinda like how your cell phone works? Obviously, routing huge holes in the guitar isn't a big deal at this point. It's already more or less semi-hollow (no wood beneath the pickguard except at the edges), and I might even be able to build a simple little circuit, if that's the best way to do it.

Thanks in advance,
David

bongomania · #2 06-06-2011, 10:38 PM

It's not a super easy thing to DIY, but it is "doable". FWIW, there is an excellent preamp you can buy ready-made that has this rechargeable feature: the John East P-Retro. Unfortunately, it costs a fair bit.

SolidFooting · #3 06-06-2011, 10:49 PM

Wow! Yeah, that's worth more than the whole guitar, even with the upgrades thrown in and the external speaker cabinet I built to go with it. I would assume the problem is building some sort of trickle charger. Is that it, or is the problem with wiring the battery to the charger and to the amp simultaneously?

Thanks!

bongomania · #4 06-06-2011, 11:06 PM

I think the main issue is in finding a charger/battery combination module that will fit in the cavity, and is designed to output regulated 9VDC when charged. I think to build it yourself, you'd end up with something way bigger than would fit in the cavity--so the goal would be to find some prefab miniature device that does what you need with minimal modification.

SolidFooting · #5 06-07-2011, 12:11 AM

Let's say I were to use something like this:

Amazon.com: Hitech 9V Smart Charger with 1 9V 120mAh Ni-Cd battery: Electronics

Couldn't I just take it out of its enclosure, put it in a project box of some sort, and run a wire from the positive and negative leads of the charger into the guitar? Is there any reason the charger can't be external?

SGD Lutherie · #6 06-07-2011, 06:38 AM

Why not wire in a real preamp made for the purpose, that will use less power, and have a switch for the amp/speaker combo when it's needed.

Also since you have the room, use AA or C cells to add up to 9V. They have more current and will last longer.

SolidFooting · #7 06-07-2011, 11:11 AM

90% of her practice is either through the internal speaker or an external passive speaker cabinet. Before I wired in the amp, she practiced unplugged, untuned, and generally singing in a completely different key. This is much better.

SGD Lutherie · #8 06-07-2011, 11:22 AM

Quote:

Originally Posted by SolidFooting

90% of her practice is either through the internal speaker or an external passive speaker cabinet. Before I wired in the amp, she practiced unplugged, untuned, and generally singing in a completely different key. This is much better.

Of course it's good to practice though an amp, no one is denying that. But I don't see how it's better to have the amp in the bass. It's a compromise, as you have discovered. You could have built that amp in a small case with either AC power, a larger battery pack, or a rechargeable battery. Plus it can't sound as good as a larger amp or even headphones. I practice through my Monsoon computer speakers, or Sennheiser headphones. I can hear my self just fine, and I'm not stuck playing one bass.

If she only needs the amp for practice at home, just hook up an AC power jack on the bass. Then have the amp bypassed for playing through a real amp.

cybersnyder · #9 06-07-2011, 11:36 AM

Get her an acoustic bass.

Big Brother · #10 06-07-2011, 11:39 AM

I am not sure of the voltage but maybe you could rip an electric toothbrush apart with its attendant electronics and even set it up such that you just set it down on the original charger, perhaps built into your guitar stand, as opposed to plugging it in.

Would be very cool as long as you have a backup charger handy.

The downside is that you can't use a regular battery in a pinch.