Pre-refined: Modify the battery compartment?

[shredmiyagi]

So I love my '98 Mahogany Fly Classic (here I am playing it: https://www.youtube.com/watch?v=vdjpJPDtx4E), but over the years the battery life has worsened. I fear it's draining while not plugged in, cause I've had more batteries fail on me in the past year than ever. Also, the the thin wires are hanging by a thread. Changing the 9v is obviously a total pain-in-the-*** when you're on stage (I need a flathead, usually some nosehead pliers unless the battery scoots out effortlessly, but even then I sometimes need to catch the wire as it recedes to the back).

Has anybody successfully installed a new battery compartment, one that skips on the wire snap and replaces it with a touch plate and maybe some sponging on the backplate to push against it? Just looking for any ideas or parts, in case somebody's done it.

[sybersitizen]

I won't try to answer the question about redoing the whole compartment; but the easy fix for getting the battery out is to do something special when you first put it in: Affix a piece of tape to the side of the battery, leaving a folded edge that you can grab and pull when it needs to be replaced. Works like a charm.

[shredmiyagi]

Well since switching to a thinner battery , getting the 9v out has been less an issue. But the wire is on the verge of snapping, and it definitely coils back to the end, so I need a tool to safely pull it out to connect a new battery.

[ChrisNB]

It sounds like you need to replace the battery connector: some short-circuiting due to frayed wires could be the cause of shortened battery life. The ‘Keystone’ brand is excellent: they offer phosphor bronze contacts on their “premium” parts, for great conductivity along with reliable firm contact.
IMO, don’t even think about modifying the cavity.

[Big Swifty]

Haven't done the touch plate mod, but often thought about it...

I've had to replace the battery snap a couple of times over the last 20 years or so, not a big job.

Be interested to see if you come up with a touch plate type solution, and completely agree with ChrisNB re modifying the cavity itself!

B.S.

[ChrisNB]

...not a big job.

...provided you can solder. I recommend a dab of flux before reheating the joints.

One other possible cause of short battery life could be the switch on your jack: does the LED respond as it should when plugging/unplugging?

[billy]

First, great playing all around!  The bass player doing the George Benson thing is amazing.

The tape idea works great, you can add the date you install too, which helps since they usually last me at least a few months. 

You've almost definitely got a short for it to be failing so quickly, either at the wires or with the switch- watch that led on the back for sure.

One thing that might help in the short term- the screw slot is designed to work with a US dime, no screwdriver required.

You can get a better battery snap from digikey.com with longer wires for not much $$.   https://www.digikey.com/products/en?mpart=BS12I-MC&vendor=61

As for modding the compartment for spring style contacts, it's a little tricky.  You need a way to increase the depth of the cavity, and probably also open up the sides too.  Then, you need to add foam which is strong enough to compress the spring contacts but not so strong that you can't get the cover back on.  And probably most important, you need to be sure that the polarity is right.  A 9V battery can fry stuff on the pcb if you hook it up backwards.

An easier thing to try might be to add the refined style battery box to your rear cover plate.  This is semi-reversible too, since you can get a new back plate.  The trick here is locating the box so it doesn't interfere with anything inside the cavity.

Good luck!

[ChrisNB]

The trick here is locating the box so it doesn't interfere with anything inside the cavity.

I considered the feasibility of this on a Fly I was working on yesterday, and really don't think there would be space, in breadth or depth.

[billy]

yeah, I forget how much space that pre-ref pcb takes up.  Still, there are different boxes available and with a little box modification and careful planning, there might be room.

Another consideration might be to use the 3V coin cell batteries in series to get 9V.  They sell battery boxes for those too.  Probably won't last as long, but could be a lot easier to change.  I think I might use this approach on one of my shell projects.

[ChrisNB]

The coin-cell option occurred to me: as you say, these are less powerful than the PP3 9v (itself not ideal for guitars, really). Schertler acoustic pickup systems use them.

A USB chargeable solution, as Fishman Fluence uses, would be neat. Another possibility might be a custom battery cavity plate with a DC jack...then mount a battery pack (AA cells for long life) on the strap, and plug in!

Anyway, I think that once shredmiyagi solves the likely shorting issue, such measures won’t be worth the trouble.

[billy]

well said.  9V batteries are not very energy dense, esp compared to 6 AA or even 6 AAA.  The 2032s are not very dense at all but the good news all around is that the pcb shouldn't draw much as long as it gets about 9V.

Best thing by far is fix the short, and replace the battery snap.

[jb63]

Late to the show here, but what I do is glue a little strap on my battery that makes it easy to pull out and put back in. It comes right off and goes onto the new battery when I change it. I've replaced almost every single pre-refined 9v snap-on on every parker i've owned with a $3 part I used to be able to buy at Radio Shack.

That's the cheapest, easiest of all the problems I've eve one across, and you shouldn't be scared to try. Its empowering!