12 volt battery position

Morris Team 2538 Plaid Pillagers are asking you:

Do your batteries have to be positioned vertically? Or is it possible to position them horizontally? Thanks!

No rules govern position or orientation of batteries. The only thing limiting placement is the length of the cables.

Morris Team 2538 Plaid Pillagers:

Thanks for the clarification.

You may mount either battery in any configuration. It is recommended, however, not to charge the battery upside down. I tell folks not to mount the battery upside down in the robot since it makes it easir for the terminals to come in contact with the robot frame.

Just to elaborate on Al’s comments.

Make sure the terminals are insulated with multiple wraps or tape or use heat shrink tubing. Absolutely prevent the terminals from contacting the metal frame. It makes a big mess !!

we have ours mounted vertically but that’s just because of room issues. Personally, I would’ve gone with vertical anyways. You can have a lot more support to stop the battery from popping out than horizontally.

We did some research on this.

You may position your battery either way - the rules allow any orientation.
The quality of the battery is not affected in anyway between vertical positioning and horizontal. That’s output quality when the battery is being used.

Thanks for the warning about not charging upside down though, we didn’t come across anything about re-charge.

Sam

The reasoning behind that is that there’s a safety valve in there, which you cannot see, but it is located on top. If the valve goes off (which is rare anyway) with the valve on the bottom, you can spew gelled acid. No reason to charge it upside down, so prevent that accident before it happens.

Don

Really?

That’s the first I have ever heard of a safety valve in batteries. Care to share your source?

It’s true, even I can learn something new every day :wink:

Just google around and find an explanation of how gel-cels works. Johnson Controls probably has one. There is a wiki below. These gel cells are a modern variation of the lead- liquid acid battery that goes back to the telegraph era of the 1800’s. And is used in your car.

It is possible for the gel-cell to create hydrogen gas just like their liquid counterparts. go here and search for ‘gas’ http://en.wikipedia.org/wiki/Battery_(electricity)

If you examine your battery, you will see a small insert about 3/4" wide running across the top of the battery. The safety valves live underneath that insert, one for each of the six cells. During charging, in particular, heat can be generated within each cell as well as a little gas. The valve is in place should the pressure build to a point where the case could be compromised. Should the battery encounter one of these “high pressure” episodes in the inverted position, some electrolyte could be expelled. This is a rare event but it is simply remedied by charging in the “terminals up” orientation. These batteries also make some water vapor during high current charge/discharge cycles that may also vent through the valves. As more water is lost, battery capacity will be reduced. Our batteries are of the AGM (absorbed glass mat) gelled design. So when researching batteries, some of the info on gel cell batteries may not fully apply to the batteries we use. AGM batteries are less suscpetible to some of the events described above in comparison with the standard gel cell variety.

Shown here, during an “impact test” at high speeds. :eek:
http://www.chiefdelphi.com/media/photos/19280

I don’t know of any restrictions, but you should think logical about your placement, connectors, and this year where the ball will be in comparison to your robot. Like if the trackball is gonna’ have to sink into your bot, then ur battery should probably be laid down…etc.