running bot off car battery?
 

there are some parades that we are thinking about going to and we would like to bring the robot. The problem with this is that it would drain the battery something fierce. Would it be possible to run the bot off a car battery, would it damage anything, and any estimations on how long it would run? we would only be using 2 drill motors. thanks!

As long as it's 12 volts (and nearly every car battery is), it won't hurt any of the electric components.

Since most car batteries are not sealed, you would have to be careful on how its mounted- it must be straight up and no chance of it getting tipped over. Battery acid sucks.

It's also likely to be heavier which might reduce your speed, just keep that in mind. Your motors are also likely to get nice a toasty if you run them long, you might invest in a can of coolant.

-Andy A.

we've run robots using one of those battery portable jumper kits- it worked fine.

Be warned though, typical car batteries are not designed for deep discharge cycles. If you drain the battery, chances are you will cause harm to your car battery.

Deep cycle (typically marine) batterys don't have this problem. They're more expensive though.

You might also consider hooking up your competition batteries in parallel to double your runtime.

Those have a battery not unlike what we are given by FIRST. I wouldn't expect it to last any longer than what we have.

Perhaps you should find someone with a truck to hold your team and a trailer to hold your robot like we do!!!

Most of the team sits on the truck and the drivers sit on the tailgate...

We have a few people on the trailer and they usually collect the scoring objects (balls or boxes this year) we demonstrate the robots abilities instead of just drivin the bot down the road!!!!!

The people on the trailer also change the batts if needed!

The problem is that we were a stacker and that never worked so all we can do is drive..... hehe. :rolleyes:

It will work
 

Car batteries will work fine, just be sure the battery remains in an upright position becaus most are not sealed cell batteries!

This is what I would use although it is quite pricey. It is the only one you would have to buy for a long time though.:]

Parade in Canton?
 

Parades in Canton? I live in Canton and I don't know about any parades. You should let us know what parades you're talking about so I can show up.

-Chris

We did this for our homecoming parade: Get a big enough trailer where you can drive the robot around resonably well. Then you can drive the robot around on the trailer. Make sure there are side railings you don't want your bot to fall off a moving vehicle! We had like a 15ft. x 6 ft. trailer.

do what we did
 

we made carousal of six robotics that ran off of two cip motors and we (6 teams) walked behind the float. It also had a FIRST symbol that was suspended in the air which almost hit street lights..i cant find pic right now...but i will post it soon. It was awesome.

We ran just fine in our memorial day parade last year with 3 batteries. I believe the entire length was around 2 miles or so.

A typical car battery should work just fine. Be advised that the safety issues with FIRST batteries are multiplied with a car battery. It is much heavier and higher available current than the robot battery. Be very careful not to short across the terminals. Insulate very well, all wiring from the battery to the robot. I would suggest removing the breakers for motors that won't be used so that they don't accidentally get turned on when people are close by. (i.e. just drive motors and light because the light is cool) Try to give the robot some rest throughout the parade, especially if it is a hot day and the sun is beating down on the robot. Motors and speed controllers that get hot during driving will smoke during constant use in heat and sun.

As an extra added precaution, you might want to add a high current fuse near the battery, in case the wiring should short in the robot before the 120 amp breaker trips. Always secure the battery so that is does not tip over. Add flags, that's always cool!

We drove 980's 2002 robot in a parade that was 2 miles long using only 2 batteries. It was cool driving a robot through the streets of Downtown Los Angeles. We were going pretty slow most of the way. The robot ran only on drill motors which didn't really get hot. We followed in a chase vehicle with the radio and OI powered off a battery.