Backup Battery...Yay or Neh?

So the Offical 2004 season has been over for a few weeks now and i was wondering what everyones thoughts on the backup battery was, and what you would like to see of it in the future.

It was good, because in past years if you ever lost batter connection, or had a incidental short somewhere when got hit… you could not compete. Your controller would keep resetting and it was quite annoying. The backup batter kept it from being reset which was nice, and you didn’t have to wait for the controller to boot up each time.

It didn’t do any harm, only annoying part was having to charge it, which rarely happend.

I did not like how it controlled the servo’s. Other than that it was alright. just change it so it does not controll the servo’s and its all good!

I believe that it was a good feature. The only problem that I had with it was the power remaining after the robot was turned off. I didn’t know until comp that the Reset button could turn it off afterwords, so for most of the time we just pulled out the plug, which stripped the connection, and posed a few power problems. Other than this little fact, however, I think that it was a useful addition.

The battery adds to the complexity of the system. Currently, you must hit a reset button to turn the robot controller off. If there was some smarter software on the robot controller controling power management some of the complexity would be removed. For instance, if the RC doesn’t receieve power from it’s 12V supply for more than 10 seconds I think it’s safe to say the RC no longer needs to continue running and should automaticly shut itself off.

Was that documented somewhere that I missed? Or was this just a secret? I wish I had known that.

Also, like BillyGoats, I don’t think the battery should power the servos. I’d also like to see the battery be charged from the main robot battery (Especially if it is going to power the servos).

I think the backup battery was a good step this year, and with continual improvment will be very valuable.

We first found out from an inspector.

One team, I believe it was 980, was helping us out and made us aware of this little secret. Turns out, they hit the reset button by accident and found it out that way.

It already does this, however the timeout is longer than 10 seconds. It will power down automatically after 2.5 minutes.

I also agree about it powering the servos - it would be a nice enhancement if the servos could be powered off the regular battery (and perhaps fall back to the backup if the main battery dies). My reasoning is that by it being the only source of power for the servos, it’s not really a backup battery anymore, but just another required power source. When I think of a backup system, if the backup fails while the primary system is functional, the user shouldn’t notice. In this case, if the backup battery fails (and assuming you use servos on your robot), your robot will be crippled even if the primary battery is fine.

Unfortunately, yes… :frowning: Under the “RESET Button” section of the RC reference guide:

If the Robot Controller is running from Battery Backup power, you must press the RESET button to power off the RC after Main power is removed.

I remember someone on our team figured that out the first day we had the kit, but it wasn’t me. I guess my engineering instinct kicked in: why read the section on the “reset button”? Everyone knows what a reset button does, right? D’oh.

I’m neutral about it really. I don’t think it was very much of a benefit, unless you had matches close together, not many spare batteries, and a high current draw on your robot.

I think it should be an optional component. My team almost didn’t pass inspection, due to the couple of oz. the battery weights. :slight_smile:

Some weird stuff happened to us with the backup battery. When we didnt have it plugged in, our speed controllers spazed out, and the drive motors jerked around. When it was plugged in, everything ran smoothly. I don’t know if that just happened to us, or if it was a problem that others had.

Beside that, I think the backup battery was a good idea.

Oh okay thanks, 2.5 minutes. Seems unnecesarily long, but it’s a step in the right direction.

I agree on the servo power issue. It was very misleading for IFI to call the battery a “backup” but have it actually be the primary power source. Backup is usually used to describe a secondary power source. I really hope IFI adds in the regulators and provides primary power to the servos. I don’t see having a redundant supply for the servos as being very important.

We didn’t found out about it 'till the 4th week of build season. One of Innovation First papers about this year’s control system does say something about that…
From this thread I take that lots of people didn’t read it, which kind of confirms something I had thought earlier this year… The documentation on the 2004 control system is a bit confuse and obscure; it should have been more publicized considering the drastic change from last year’s electronics.

it was a good idea-- not a good idea when u can’t find the charger or somebody fries one now-- lol–

and remembering to plug it in sort of helps- one thing we forgot to check was it in or not since we weren’t use to having it on the robot–just the main battery all zipped tied up

The backup battery completely removed the problem of low voltage resets we’ve experienced in the past. I wonder if those who unconditionally hated the backup battery have had the pleasure of the low-voltage reset before? To me that alone made it worthwhile.
It would be nice if there was a more intelligent sync between the main power system and the backup battery net-- but I understand that this year’s system was probably intentionally brutally simple from a design and implementation standpoint.

we never seemed to have a need for the back up battery aside from competition when it is required we don’t even plug it in.

and as for turn off the RC we were told at the SLT regional by IFI after the third time we forgot to plug in the battery.

Note I don’t like the backup much, but that I did mention that. :slight_smile:

To all those who are indifferent about the backups, just don’t worry about them and you’ll be fine. The RC still runs off of the main battery, and a lot of teams will never have to worry.

To us, they are a godsend, considering the current draw our robot has. Two years ago, when we tried six motor drive for the first time, lack of a backup battery was one of two major setbacks; this lack of available power would cut out our RC in pushing matches. In 2003, they fixed the other problem with the nice 120 amp breakers we take for granted (which used to sometimes pop when we stalled our gearbox). Finally this year the second problem was fixed and we no longer have to worry about our RC cutting out after too much pushing.

In the end, there’s nothing really that should make you unhappy with the backup batteries; either they are very useful, or they are neither bad nor good.

What i was told about time delay shut down after the main power is cut is for matches. When the power is cut or a main battery is lost during a match, or even if the main battery is never turned on, but the “back-up” battery is still there, the LED’s still blink. Other then the LED blocks this year your robot alone has no alliance distinction (red or blue) while on the field. The time length supplies the estimated amount of time it would be from the start of a match until the scoring of that match is completed by the refs, so they know who is red and blue right away. Now also when your bot was under arena control and lost the main battery, the light pace changed if the bot was being powered by only the smaller “back-up” battery.

Excellent, I forgot about that. It looks like 2.5 minutes was a good choice after all.