Re: Driver station power
 

The post about charging the driver station (laptop) with a robot battery is a common practice and is very beneficial while at competition. It has definitely saved our bacon many times. Don't use a large lead acid. They are heavy and spillable.

I hope no one would charge a robot battery with a robot battery. This doesn't seem like a very practical approach...

The battery provides a voltage source, the devices plugged in draw a current. The current draw is dependent on the load of the device(s). For instance, a laptop at idle will consume less power than at 100% CPU utilization. Since most tasks are near-idle for the average laptop, a laptop plugged into a robot battery should last a good portion of a day.

Re: Driver station power
 

This brings up another interesting matter, so to speak -- how and where are elements like gold fabricated from lighter elements and energy? The answer is really quite something...

Re: Driver station power
 

Alchemy is reborn!!!

Re: Driver station power
 

In particle accelerators and nuclear reactors.

And, in some cosmological theories, in stars.

Re: Driver station power
 

As I work at a battery store, I can tell you this battery should suffice for one day at a time, provided you plug it into a charger each night after a full day of use at a competition.

If a less heavy battery is needed (i'm guessing you don't want to carry around a car battery all day. Trust me, it gets heavier than you would think), you can look into Shorai lithium motorcycle batteries, they weigh about 2 pounds so it would be almost nothing in a driver station, but they run ~$200 in-store, ~$100 online, depending on which one you get. Still 12V, and last longer than a lead-acid battery

Re: Driver station power
 

Just buy two 11.1 6000mah lipos and place them parallel. You will then have a 12A battery bank, lipo for under $50. You would get one of those lipos then, dirt cheap.

Re: Driver station power
 

Worth a read: Stellar nucleosynthesis. Not directly helpful for powering a driver station though!

Re: Driver station power
 

At that point why not use a competition legal battery? About the same price more amp hours.

Re: Driver station power
 

Even better: get two of the non-legal MK-ES18 "replacement" batteries off batterysharks.com or another site for the price of one legal battery. Use them for your robot in the pits, training, demonstrations, and powering inverters for charging your driver station or stands laptops.

FYI: We've tested the non-legal batteries using the industry standard tests. They are at least as good, and in some cases, better.

Re: Driver station power
 

I don't think the issue is the legal ones being better or worse. It is to ensure the robots at competition have the same energy available. The advantage of buying legal ones is you can use them at competition & don't have to worry about segregating the non legal ones. Worth the price difference to me. Although we have come across some non-legal batteries at garage sales too cheap to pass up. YMMV

BTW we are having some custom Li ion batteries built. About the same size & wt as the legal battery. Double the amp hrs. Too bad we cannot use them at competition. :)

Re: Driver station power
 

If you assemble a lipo yourself, it can be chaeper than buying it. Just buy some 5000mah cells together and you have a lipo that will charge/discharge rapidly and hold twice the power.

Re: Driver station power
 

I've always believed the case is that the MK and Enersys brands are stable (and thus have the same specs). The replacement batteries are probably made in the same factory, but the brand names and case color change by the month.

Re: Driver station power
 

Be careful when you are looking at battery specs. I looked up a few lithium ion batteries for this response. A stated motorcycle replacement 20 AH battery, can only deliver 200 amps max compared with our 600+ amps. While it has a longer life and can charge at over 10 amps, it also has a smart circuit that shuts off the battery when it falls below 8 volts. Most LI replacement batteries have some internal circuitry to limit currents or prevent unusual charge conditions. It cost $280 by the way. While our current batteries have an acidic electrolyte, the internal chemicals will not set themselves on fire when exposed to the atmosphere and do not maintain an above normal internal pressure as Li types do.

Re: Driver station power
 

As Al says this is something that needs to be well thought out. One of our sponsors packages batteries for military / industrial applications. They are doing the engineering for the battery I mentioned. As Boeing & others with more knowledge than me have found out, Li ion can be tricky.
We are using the standard 120amp breaker switch. It can flow more current than that for short periods, but it will trip.

Just recently a Telsa "hit something" and set its battery pack on fire. Much to the consternation to the FD that tried to put it out.

Re: Driver station power
 

I guess that is where a supercap is great. It will take over for the power surges