Wal-Mart Battery - field problems

[gmm6797]

Got my cable from Ed the other day, and tried it on the closest battery and poof, it tripped the battery.

This is nothing about tne cable from Ed, but it is a fact that these batteries are not a guarente to work correctly in the field, so be warned.

It seems like it is a "your mileage will vary from battery to battery".

And the cabel from Ed is nice and a lot better build than the ShitShack version I was using before.

[scb]

i cut the cable that came with my walmart batteries and soldered a 4 pin xlr to the end.  simple solution to get it to play nice with the toys

[coloartist]

I would think you have a bad battery.

I have 7 of them, and haven't had a problem.

[gmm6797]

I have 3 of them that I have used interchangably and not noted which one (or ones) have crapped out, I am going to make a not of which one caused the problem, and see if I can repeat it.

A pain in the butt if I cant narrow it down 

[gmm6797]

OK, going to the show
2 fully charged batteries in hand, new "Ed" cable, power cord... both tested over and over again with Schoepd VMS02ib pre-amp @ home, and no issues.

Set up the rig, wire everything, testing and all is working.  Pre on and off all is good.

Looking like show time, Wal-Mart battery, dead (well tripped and will not put power out or show any test lights).  Check the lights on #2, hook it up, poof, goes dead.

Put in the 8 AA batteries, and run fine for the show.

Anyone have any freaking clue what could be causing this?

I had no problems running the same mics and pre and Wal-Mart battieries all summer (about 15-20 shows), but since late August, I keep getting shit on.

Thanks

[it-goes-to-eleven]

So the battery went dead when you hooked it up... BEFORE you turned anything on?

Can you confirm that nothing in your rig draws power until it is turned on?  Your cable just runs from the lion to the vms and nothing else?

Are these batteries known to work with other rigs, etc?

I'd troubleshoot it with a dvm.  If you plug a bat in and it trips, I'd unplug that cable from the battery and immediately measure the resistance the battery is seeing on that cable. I'm guessing you'll see a short (possibly inside the vms).

While testing, continuously measure the resistance the battery would see if plugged in while you wiggle and stress each connection.  You will probably need some clips to hold the probes or have someone do it.  Wiggle the cabbles slowly and watch for any shorts or variations.

When is the last time you were able to power the vms via external battery?

[gmm6797]

So the battery went dead when you hooked it up... BEFORE you turned anything on?

The 1st one did power it while hooking up the rig, but not when I turned the pre on the 2nd time
The 2nd one testes fine, and as soon as I turned the pre on, it was dead

Can you confirm that nothing in your rig draws power until it is turned on?  Your cable just runs from the lion to the vms and nothing else?

I would assime not, as the power switch is set to "off"

Are these batteries known to work with other rigs, etc?

I do not have any other gear handy, but I can test next show with others, not sure when that will be

I'd troubleshoot it with a dvm.  If you plug a bat in and it trips, I'd unplug that cable from the battery and immediately measure the resistance the battery is seeing on that cable. I'm guessing you'll see a short (possibly inside the vms).
While testing, continuously measure the resistance the battery would see if plugged in while you wiggle and stress each connection.  You will probably need some clips to hold the probes or have someone do it.  Wiggle the cabbles slowly and watch for any shorts or variations.

Unfortunatley all of this is way over my head.  I will admit I am not an engineer, but I will check with another friend of mine who is on this list and uses these batteries an lives 30min away to see if he follows.  He is also the one who pushed me to used these with my VMS since he had success.

When is the last time you were able to power the vms via external battery?

September 13th, I even labeled that battery as a possible bad one (as I have 3 or 4 of these).

I ran the same 2 show after show after show this summer with no problems.  Several people here blames by Radio Shack cable, so I grabbed a cable from Ed, which was what I used Wednesday night.

The PreAmp was sent back to Schoeps and was given a 100% bill of health in December, but it has been used about 30-40 times since then, about 1/2 with the Wal-Mart battery.

Thanks!

[it-goes-to-eleven]

If the batteries are good then I think you have a short somewhere in your rig.  Could be a single tiny strand of wire in the socket of your vms or inside..

My Grandfather gave me my first voltmeter when I was about 8...  They aren't hard to use...  Heck, my 4th grade teacher had us building flashlights and winding armatures to build electric motors (he was a cool guy!).  I consider being able to use a dvm a basic life survival skill.. These days you can get a decent digital dvm for about $10 on sale. $20-$25 tops. I'm sure there are some excellent tutorials on the web.  Empower yourself!

[Digital Quality]

A short or some other current spike. It'd be really useful if you could measure the peak current - even when connecting to the other batteries. There could also be a bad resistor in there that's allowing capacitance to charge up too quickly.

Edit: Have you tried plugging things in the other way? You said you plug in the battery then the pre. Try plugging in the pre first and then connecting to the battery. If the connector for the battery end of the cable fits a little better it could reduce that momentary current spike.

[gmm6797]

A short or some other current spike. It'd be really useful if you could measure the peak current - even when connecting to the other batteries. There could also be a bad resistor in there that's allowing capacitance to charge up too quickly.

Edit: Have you tried plugging things in the other way? You said you plug in the battery then the pre. Try plugging in the pre first and then connecting to the battery. If the connector for the battery end of the cable fits a little better it could reduce that momentary current spike.

Well, I never actually "plug" in that specific of an order, but I am going to mess with it some more... the only thing I find weird (in a good way) is the VMS is 100% fine with AA batteries in it, so it is actually comepltly useable for 4+ hours this way.  The Wa-Mart battery sould give me 12+ hours... but have not needed that long of a run since 1989 

If the batteries are good then I think you have a short somewhere in your rig.  Could be a single tiny strand of wire in the socket of your vms or inside..

My Grandfather gave me my first voltmeter when I was about 8...  They aren't hard to use...  Heck, my 4th grade teacher had us building flashlights and winding armatures to build electric motors (he was a cool guy!).  I consider being able to use a dvm a basic life survival skill.. These days you can get a decent digital dvm for about $10 on sale. $20-$25 tops. I'm sure there are some excellent tutorials on the web.  Empower yourself!

Well, as much as I understand what you are saying, I know when to say no, and this is one of those times!
I am not good with the electronics side of being a geek, and I would rather pay someone else an hourly rate to do this... As I have the luck where I would fry my VMS, battery, cable, etc.. and that is harder to replace out of my own wallet! 
Call me chicken if you want

[gmm6797]

Just bougth a custom cable from Ed @ KindKables, so that is not the problem.... as I trust Ed's cables like no other, as others here in this thread do too... :-(

This has only happened to me once... well twice in rapid succession... but with two different batts.  One mine and the other the spare of a kind local taper who is tramping around Scotland right now... 

I know that my wire lash up, battery to UA5, is suspect but if it can stay put and not move it's OK.  I think the connector is also key but I too use a hacked connector that comes with the battery to take power from the battery.  Someone has posted here on TS somewhere that the connectors (prolly the Rat Shacks) are inconsistent in build quality and he's convinced that this is part of the shorting problem.  The battery seems to be dead but in fact the charging circuit (I imagine) is some how "stuck" in dark lamp mode when shorted... until you hit it with power from the wall wart charger.  My fix is to carry the damn AC charger now and trust the fact that the batteries have performed well with the same hardware for basically two years.  (Sorry if any of this is a rehash, I haven't read the whole thread.) 

[willndmb]

Edit: Have you tried plugging things in the other way? You said you plug in the battery then the pre. Try plugging in the pre first and then connecting to the battery. If the connector for the battery end of the cable fits a little better it could reduce that momentary current spike.

i have heard of this being the prob from others too
if they plugged the battery in 1st it woudl die, if they plugged the pre in 1st they were ok

i always plug the pre in 1st and have never had a prob that way, see if you can test it out more at home like that
going batt > pre, pre > batt

[gmm6797]

i have heard of this being the prob from others too
if they plugged the battery in 1st it woudl die, if they plugged the pre in 1st they were ok

i always plug the pre in 1st and have never had a prob that way, see if you can test it out more at home like that
going batt > pre, pre > batt

This is crazy, but I will give it a try. 

So you are saying plug the cable into the battery then plug the cable into the pre... and not the other way around?

[dnsacks]

other way around.  Plug the cable into the pre first, then confirm the pre is turned OFF.  Finally, plug the cable into the battery.  If the battery shorts/fails before you turn on the pre, I'd be fairly confident you have a short somewhere in your cable/pre.  If the battery doesn't short/fail after plugging in in, power up the pre.

[gmm6797]

other way around.  Plug the cable into the pre first, then confirm the pre is turned OFF.  Finally, plug the cable into the battery.  If the battery shorts/fails before you turn on the pre, I'd be fairly confident you have a short somewhere in your cable/pre.  If the battery doesn't short/fail after plugging in in, power up the pre.

Ah, OK.... crazier things have worked, so Ill give it a whirl

Thanks!