We just use the load tester you bought to test batteries preseason. During competition we a Fluke voltmeter to check how charged the battery is. As for a system of charging batteries, we label each battery a letter. Starting with A we use them sequentially for each match. This seems to work for us because the battery we use next is the one that has been charging the longest and theoretically should have the best charge. I hope this helps!
Our battery charging station uses 2 4-bank battery chargers (http://tinyurl.com/a95lyts) to charge our batteries. It can probably hold 12 batteries, but we only have 8 good ones which is why we bought two 4-bank chargers. The chargers have led lights that are supposed to represent the charging state of each battery, and they seem pretty reliable, but we just use a standard multimeter to test batteries. That Wel-bilt tester seems like it would work fine, but it doesn’t seem to do anything that a multimeter couldn’t. Anyways hope this helped!
This. I accidentally put a battery just like this in our robot in 2009, went from 13 to 7 volts after the match started (the battery had been killed by trying to test a motor that was shorted, and happened to find a way into the rotation of good ones).
You can ask Akash, we were allied with 11 in that match. There’s nothing worse than losing a match because of an error.
Edit: I wish I had a battery beak, it would have prevented the mistake from ever happening. Reason being that the battery beak puts a load on the battery, so if it’s actually dead, the beak will show it. Best. Tool. Ever. Wish they existed in '09
Using a multimeter to check the voltage of a battery is only accurate to know the charge status of a battery, not whether it is “healthy” or not. Some batteries may appear to be fine after checking the voltage but will not be able to provide high current draw without significant voltage drops.
Load testers will give a more accurate assessment of the health of a battery.
I would recommend against the use of the device you list. It is intended for batteries with a much higher capacity/peak current. Continued use of this device is likely to shorten your battery life.
The use of the West Mountain Radio CBA III or the Battery Beak is a much better choice for FRC batteries. The CBA will allow you to test the battery the same way method as used by the manufacturer and the Battery Beak is a simple, pocket tool to give a good indication of battery health.
As pointed out above, a voltmeter tells you nothing other than a cell is shorted of the battery is open.
The sheet is hard to interpret but the specs state CCA of 200-1000 CCA. Each test lasts 5 seconds. If the tester is in the 200 amp setting it might be OK for our batteries but we rarely will draw current for that length of time. My general rule of thumb is always to submit the battery to the least amount of shock. This type of tester will ultimately lead to decreased life in my opinion.
I don’t know all the specifics but 955 built a 4 battery cart with a custom board that drains batteries all the way before charging them again to ensure maximum charge. Probably too much to do before competition as it took them 3 years
That is good to know that this tester may not harm the batteries, as I certainly
wouldn’t want to put any additional drain on the battery in the process…
I’m not sure but I am under the impression that when this tester is plugged into a 12 v
battery that it is measuring the voltage under a load (unlike a DMM/ Voltmeter might do)
CCA start test is an additional load test that is selected by adjusting the
CCA voltage on the tester before performing the CCA start test.
Is this correct or is the tester only reading the voltage without a load (like a DMM/ Voltmeter
might do) when the CCA start test button is not pressed?
I wanted to do more than just measure the voltage as I experienced the same situation once
where we had a battery that measured 13 V and it died too soon during a competition…
Once is enough for me thanks…
OK, I just found out that the battery is not under load until you press
the start test button which applies a load based upon the CCA
(cold cranking amps) that is selected to match what the battery is rated
at but what would be a safe value of this to test the batteries against?
Aside from a charging station/battery beak, we cut up red and green pool noodles in 1 inch slices (the kind with the hollow center). When a battery comes off the robot after a match, we pop a red noodle around the wire. When the battery is fully charged (and checked with the beak), we put a green noodle on it. This way, we always have a stock of recognizable and fresh batteries for the quick turnaround matches on Saturday afternoons.
This tester is clearly marketed as a 125 amp tester. I doubt that the selection of the CCA rating affects the load that the tester actually supplies – only the way the tester interprets the data and displays it on the 3 LEDs. But to be on the safe side, set the CCA to the lowest value anyway (200).
I recommend that you ignore the LED readout, and use the actual voltage under load, and compare it to the value for a known good battery, and keep a time history of each battery’s results to see trends.