I just purchased the 180w version with the color screen. (Although I’m a little confused since it has 4 plugs… A+ A- V+ V-… which one do I use for the capacity test?)If you can afford it, i'd go the 180w version for $10 more.
Also depends on how soon you need it. Coming from Aliexpress means China, which means likely at least a month to get to you.
That voltage drop could be due to high cell internal resistance (old and used cell), or poor wiring. Hard to tell.
Good catch! I can’t read where it said it went down to 2.77v? The smallest I saw was 2.85v when he started the test. The clips I used were supplied by the Chinese company, but it was 14AWG wire so not that thin and it was connected well to the alligator clips. I’m not so sure I would have gotten a different result with different clips.Also in the video you can see the rest leads were changed out and larger allagator clips were used. But, during single cell testing the voltage did drop to 2.77, so imagine if you had crappier connections the test rig would just read lower voltages.
Ahhh ok nice!!The V+ and V- are for remote voltage sensing. By connecting V+/- to battery terminals (just need small wires) you avoid the wiring voltage drop on the high current load wires going to A+/-. A+ and A- are the actual load.
Makes the battery voltage reading more accurate.
If doing low current loading you can just jumper V+ to A+ and V- to A-.
Hey thanks!As someone else also mentioned, the leads may have a lot of resistance when under load causing a voltage drop. They may also be fine, but by measuring where they connect to the board, you can rule out that possibility. If you measure there and it's the same (or very close) reading as what the board is reporting, you know the leads are the problem.
That’s a great idea!!That or the alligator clips, put proper ring terminals on. If the load tester thinks the cell voltage is 2.6, but you’ve proven otherwise, it’s not the cell that you should be worried about.
How would you test PV panels using one of these capacitor testers and why? I usually just hook up a DC Amp meter around the cord for the panel to see what it’s putting out.If you get one make sure it includes CV function. The one with adjustment knobs do not have CV.
CV is useful for testing PV panels.
I do shorted circuit current test using clamp on DCA meter.How would you test PV panels using one of these capacitor testers and why? I usually just hook up a DC Amp meter around the cord for the panel to see what it’s putting out.
Example:
So if I measure the battery cell terminals and come up with 3.0v and then measure at the circuit board of the capacity tester, and come up with 2.7v then I should suspect the alligator clips and swap out the clips for something better.
Interesting,I do shorted circuit current test using clamp on DCA meter.
HOBOTECH uses the load test to test the PV panel, but make sure the PV Voltage does not exceed the tester input Voltage limit.
For example, see the test at 5:00 mark.
At 3:00 mark.
I removed the old leads, bought some 10 gauge oversized thick wire, installed ring terminals, and lightly sanded them all down with 2000 grit sandpaper to remove any corrosion due to the humid Panama air.That or the alligator clips, put proper ring terminals on. If the load tester thinks the cell voltage is 2.6, but you’ve proven otherwise, it’s not the cell that you should be worried about.
Ok, I removed the 12 gauge factory alligator clips and bought some oversized 10 gauge thick wire. I connected ring terminals and then lightly sanded the connectors to remove any corrosion from the humid Panama air. I also installed a 30A fuse in line in case the tester unit blows up. (I heard here when they fail, it’s a direct short and the battery can start on fire.)From the pictures, you're seeing a voltage drop across the leads due to the load.
This is why the newer tester model has 2 separate leads for voltage sensing.
Oversize all your cables. Make sure there's solid connection between the battery and cables, and the tester unit.
When draining a large current from a small battery, you'll likely see significant voltage drop anyhow, but it shouldn't be as big as you're seeing unless the battery is bad.
Change the leads from the default factory supplied ones, as they can be really shitty with high resistance.
With new leads and solid connection points, if there's still a drop then buy the newer testing unit.
I purchased and ordered the new 4-wire remote voltage sensing version but it won't be here until next week. I checked the resistance of the 30A in-line fuse and found it was 0 ohms. Do you think there will be a problem if I try to test the capacity with this in-line fuse on the old 150w Capacity tester? I figured that as long as the voltage at the tester is close to the voltage at the battery, then I should be ok? (I won't find out until tomorrow because the batteries are locked up in a workshop here at the Marina.)Check the resistance of fuse does not defeat the lower resistance wiring. With four wire remote voltage sensing version having an inline fuse would be okay.