Rattling Battery?

[sanddrag]

Has anyone ever had a battery rattle inside? I have a Genesis battery that sounds like it has plastic pellets inside when you shake it, like a musical maraca. What causes this?

[philso]

We use several pallets of the Genesis batteries per week in the UPS' we build at work. I have never heard of such a failure mode. The only think I can think of is if the battery was dropped and part of the internal structure that holds the lead plates in place has broken, allowing the lead plates or the broken bits of plastic to rattle around inside.

[protoserge]

I'd mark it damaged and recycle it.

Are you absolutely sure the screws/standoffs on the terminals aren't loose?

[sanddrag]

Originally Posted by protoserge

Are you absolutely sure the screws/standoffs on the terminals aren't loose?

Affirmative.

[FrankJ]

Anything that stores energy has the potential of dangerous failure modes. I would call it broken and recycle it. At the very least I would only use it in a static application and not on a moving robot.

[philso]

If the screws or standoffs on the terminals are not loose, then the rattling is internal. Without knowing the internals details of the battery housing, I would do as several of the other people in this thread suggest, send it to recycling. If it is really just an "unimportant" bit of plastic rattling around, you might not have a problem. If that bit of plastic was holding the lead plates in place, the plates might end up shorting out at some point, maybe much later. Such a short can cause the battery to explode and spray acid everywhere. It is just not worth the risk, even if you are on a "low resource" team.

[protoserge]

Originally Posted by philso

It is just not worth the risk, even if you are on a "low resource" team.

The newer rules make batteries much more affordable (~$25-35 shipped for some) so I would find it hard to use the "limited resource team" line.

[sanddrag]

Originally Posted by protoserge

The newer rules make batteries much more affordable (~$25-35 shipped for some) so I would find it hard to use the "limited resource team" line.

While we're on the topic, what is your source for these $25-$35 shipped batteries? Also, given all the various choices in batteries now, is there a clear "best" battery in terms of performance?

[GreyingJay]

Do we know for sure that the battery equivalency rule introduced in 2015 is here to stay for 2016?

[protoserge]

Originally Posted by sanddrag

While we're on the topic, what is your source for these $25-$35 shipped batteries? Also, given all the various choices in batteries now, is there a clear "best" battery in terms of performance?

Check out Battery Sharks for the Sigmastek (sp?). 1 battery 2-pack. If you exercise the single battery without shipping option, you can get 4 for $115ish shipped (at least to my zip code).

I don't expect a rule change on this, but buying cheaper 12V batteries should be on all teams' radar for practice and non-competition use. Proper battery management will get at least 4 seasons of use.

There is no real difference between the batteries in capacity or construction. When I was on 836, we ran several brands (MK, Genesys, National, Sigma/Battery Sharks) and they were pretty much identical in all regards using an accepted test procedure for batteries. adciv can probably provide more detail if you require it.

[Knufire]

We've been buying batteries direct from MK Battery for $37.50 shipped.

[protoserge]

Originally Posted by Knufire

We've been buying batteries direct from MK Battery for $37.50 shipped.

Good to know. Are you using a commercial customer account or just telling them you are a FIRST team?

[Knufire]

Originally Posted by protoserge

Good to know. Are you using a commercial customer account or just telling them you are a FIRST team?

Just telling them that we're a FIRST team, looks like they already have the discount set up. Batteries shipped from Anaheim, CA on Tuesday and we received them on Thursday. I just called the number on the bottom of the website.

[Chief Hedgehog]

A bit off the OP -

Many teams have a Battery+Bulbs in their area. See if they are willing to help out - we have been fortunate enough to get a couple of batteries the last number of years for free (no shipping either!).

[philso]

Originally Posted by protoserge

The newer rules make batteries much more affordable (~$25-35 shipped for some) so I would find it hard to use the "limited resource team" line.

Yes, the cost of batteries is not that high especially when considering the overall budget. My reference to "low resource" teams speaks more to a perception than reality; i.e. it's not worth it for any team to use a battery that might blow up.