Hi,

As the post suggests, I have a project which is losing power when I bump the enclosure. Basically, the enclosure houses a simple circuit board and a battery compartment containing 2 x AA batteries.

The enclosure looks like this: http://www.jaycar.com.au/ShowLargep...c Enclosures - 135 x 70 x 24mm - Black&IMAGE=

I don't have much experience in this field and am hoping you may have seen this before and know how to resolve it.

I am thinking of stuffing the battery compartment with foam to stop the batteries from 'jiggling' perhaps, but would rather get some advice from experienced people before trialling what may be a stupid idea.

Thanks in advance!

 

find whats loose and fix it. plain and simple.

 

Use rechargeable batteries with solder connections and solder them in place.

 

Use rechargeable batteries with solder connections and solder them in place.

Who said it was the batteries that were causing this?
Could be where the wire from the battery snap attaches to the PCB or any other power connection on the PCB or other

 

If spring tension is sufficient to keep batteries in place then look for weak or broken wire connections. Sometimes solid wire can break inside the wire insulation and there wont be a problem until the wire is moved or "bumped".

just one possibility,
williamj

 

Update: Found the problem guys!

In this instance, williamj takes the golden spoon. As he eluded, I have confirmed it WAS insufficient spring tension in the battery compartment.

This is a commercial product which I am selling, so it isn't looking good to my customers. I am now putting a cylindrical 'buffer' inside the spring to minimise battery 'rattle'. This is kind of working. If you've seen smarter ways to increase tension or minimise rattle I'd love to hear it.

Thanks to everyone for your insights - greatly appreciated

Cheers, Andrew

 

In this instance, ... I have confirmed it WAS insufficient spring tension in the battery compartment.

I've used a battery holder similar to this one, and it was difficult to get the batteries out. But it did hold them firmly when the batteries were inserted.

 

Update: Found the problem guys!

In this instance, williamj takes the golden spoon. As he eluded, I have confirmed it WAS insufficient spring tension in the battery compartment.

This is a commercial product which I am selling, so it isn't looking good to my customers. I am now putting a cylindrical 'buffer' inside the spring to minimise battery 'rattle'. This is kind of working. If you've seen smarter ways to increase tension or minimise rattle I'd love to hear it.

Thanks to everyone for your insights - greatly appreciated

Cheers, Andrew

Do you have enough room for double-sided foam tape?
I've used that for several projects, not just electrical.

 

Stretch the springs a little bit so they protrude farther before you install the batteries.

 

I have designed dozens of battery operated products over my career. Believe it or not, regardless of the complexity of the product, the battery compartment is invariably the most troublesome aspect of the design, and the hardest to get right.

Mainly, this has to do with the mechanical variability of batteries from different manufacturers. Yes, there are standards, but there are also a lot of mechanical parameters that are not well defined.

There is also a dearth of good off-the-shelf battery contacts available at reasonable prices. I tend, now, to design my own.

 

I... the battery compartment is invariably the most troublesome aspect of the design, and the hardest to get right.

As a user of things with batteries, I agree. Other components (switches, contacts) fail but I'd say it's 10:1 in favor of the battery connections. Everyone knows to slap a flashlight as the first attempt to "fix" it. I go through a fair amount of dielectric grease to keep battery contacts working. Any serious appliance with a battery, like a phone, has it hard wired. Well, not springs anyway.