POLL: What do you do to test your batteries

Ok HI CD
so I am the electrical lead of FRC team 2619. I was wondering what other teams did to test their batteries. Our team uses our battery test kiosk which you can see our battery report here. Please reply to the OP with your team’s preferred method. Also shout out to the teams going to FIM St. Joseph and FIM Midland. We are planning on bring our battery test kiosk for teams to use to test their batteries. Here is a poll for if you do or don’t. Please reply with your method below

  • we test our batteries
  • we don’t test our batteries

0 voters

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how we test our batteries are in 2 different ways, we first of all use a battery beak to check voltage after it is fully charged as well as we test them the old fashioned way by putting them in a robot and checking what the driver station is reporting under load as well as how the robot is performing in general with that battery and if the battery is bad we put a red sticker on it to mark it to say that we should not use that one in a match but only as a pit battery

Does using a voltage multimeter count? After the charger says it’s good, we just check the voltage with the meter.

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I was looking more at the ranking your batteries best to worst so you know what ones you should use but that works too

We use a battery beak, and we use batteries for two years for competition, then we use them for practice/testing until they don’t work well. Also the info on the driver station is pretty helpful.

We use the CTR Battery Beak and log our batteries as a means of rating them over time. Here is a link to our public copy of our Google sheet.

You can make a copy of this and use it as you see fit. The goal is to identify batteries that are trending to failure. The challenge to to make sure your students are well versed in battery management practices all season.

we unofficially rank them. Currently have 5 batteries which have stickers on them (1-5). Just test the voltage to see what the charge is and just keep a mental note of which number battery is the best. Last year, i think it was 3 or 4…

We don’t rank our batteries, per say, but we do use a Battery Beak and a Dry Erase Board to track their voltage and internal resistance. The students who are in charge of handling batteries then use that information to select the best battery for use at any given time.

Additionally, we label all of our batteries with a number scheme that includes the year we got them (so we can determine age), and also plainly mark any batteries that are no longer suitable for use in competition (IE “Pit Batteries”).

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We ordered one of these for this year. We’ll see what it tells us about our batteries:

http://www.westmountainradio.com/cba.php

We’ll add load-resistors later.

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which one did you get?

The cheapest one because we’re broke. :slight_smile:

Correction: the CBA-IV. Not the cheapest one.

I’ve seen this mentioned a couple times- Pit Battery vs Competition/Match Battery.
About where is the mark between them?

Depends on what you are using to test them, and how frequently you replace them.

For teams that don’t frequently replace batteries, there is no cutoff and they just use the best batteries they have. (generally good to declare at least 5 batteries as competition batteries.)

For teams that replace 1 or 2 comp batteries yearly, they will likely replace their worst batteries and then take the best ones as comp batteries.

For teams that replace most of their comp batteries yearly, they will likely set a testing threshold for when to replace a battery, and then only use batteries above that threshold.

For teams that replace all of their comp batteries yearly, they may not even test them at all, but if they spend that much money on batteries, they probably test them anyway.

The cutoffs are somewhat arbitrary, but there are some general guidelines (that I don’t happen to remember) for whatever kind of testing method you choose to use.

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We test our batteries. We use a Battery Beak to check internal resistance and we use a Solar BA7 automotive battery tester (with Anderson connector installed) to get a reading of “cranking amps”. Batteries that pass our thresholds of 0.018 ohms and 100 cranking amps are approved for competition. We’ve seen the West Mtn testers but have never invested in one. One of our mentors is heavily into solar energy generation and promises us that he’ll set us up with more of a real load test capability this season.

We don’t test our batteries, really. We do keep them in order and cycle them, and also pay attention to the voltage display on the driver station. We also tend to check the voltage with a meter before using them in a match.

Since our robots are generally built with few motors, they don’t need the “best” battery to function properly. They do need a fully charged battery, with near it’s rated capacity, though.

Summer and off season are rough on batteries, they can be left discharged.

Getting students interested in batteries has been a constant struggle over the years…any tips?

The only thing that we do that I would say really gets our students interested in the is that we have a test kiosk and testing procedure that looks cool and everyone on the team should know how to use and so on. We also mention battery safety in our tech topics fairly consistently. (if I remember I will get a pic of our test kiosk tonight)

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BatteryBeak. Buy a couple new batteries every year, ‘retire’ the two oldest ones. Important to label batteries by date of acquisition.

Battery Beak for us. I have been vocal about wanting a CBA too, but bigger budget priorities keep popping up.

Make a big deal of it - that it’s simple, but very important. It’s the most important job done by a freshman most years.

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We get a quick indication using internal resistance measured with the Battery Beak. More importantly, we simulate match conditions by running them at 40A using a CBA IV until the voltage drops below 11V.