Adventures in Data Logging (EasyLog DC voltage logger)

[Old Crow]

Santa brought me an early Christmas present in mid-December and I’ve been having fun learning how to use it.

It’s an EasyLog EL-USB-3 data logger. It’s one of a series of data loggers made by Lascar Electronics, this one designed to collect DC voltage measurements in the 0-30 volt range.

The ‘USB’ in the name refers to the USB connector inside the hardware unit. That’s how you connect it to your Windows PC to set it up for a data run. Once you do that, you remove the unit from the PC’s USB port and add a plastic cap which has wires and alligator clips for connecting it to the load. After you collect the data, pull off the wired cap and once again plug the unit in to your PC to read and plot the collected data. You can also export the data in several formats.

It has storage space for 32,510 voltage readings. If I set the sample rate at 1 second, it fills up in about 9 hours. At a 2-second sample rate, it lasts 18 hours. Sample rates are 1, 2, 5, 10, 15, 20, and 30 seconds, those same increments of minutes or 1, 6, and 12 hours per sample.

Online sales listings for the device say it works in Windows 2000, XP, Vista and 7 and 8. Santa told me he almost passed on it because the listings don’t show Windows 10 support but then found that Lascar’s tech support page says the latest version of the software does indeed work with Windows 10.

Installation was easy on my Windows 10 system but I did have a small glitch. After the software installed I received a warning message that scanning had failed (I assume this is scanning of the USB ports) but right after that the driver installation ran and I was in business.

Here's a data sheet for it with more info. I believe Santa paid about $75 for it on Amazon.


I’ll show some logging runs in my next few posts.

…

 

[Old Crow]

This is an EasyLog plot of my CTEK 25000 AC-DC battery charger on the starter battery in my 2013 Tundra.

Background-

In February 2017, I contacted CTEK tech support about my charger apparently failing to go to a float voltage after it declared my battery full. I was told it does that purposely. It waits 24 hours after the top-off before turning on the maintenance mode. I wanted to see it on a plot....

(click to enlarge)



Notes:

1. I should have put the logger on and let it collect for a few minutes before connecting the charger. That would have given me a clearer starting point.

2. At first glance, the plot is pretty much as expected, i.e., charge at 14.4-ish, drop off when the battery’s full. Ramp up to 13.6 volts a day later.

3. I do see a problem, though. This charger is supposed to be temperature-compensated. Temperature at the battery post when I started was 35F and the temperature-compensation chart for this charger says it should be charging at almost 15 volts at that temperature. (I also happen to have a CTEK D250SA temperature-compensated DC-DC charger and can confirm that it charges the house battery in my Hawk in the 15-volt range at 35F.)

4. Voltage is kind of tough to estimate from the plot. But when you see it on the PC screen in the EasyLog software, there's another line on the graph. As you run that line across the graph with your mouse, the instantaneous voltage measurement is shown in text.

5. If the cross-hairs technique doesn't do it for you, you can also look at the raw data and see the date, time, and voltage measurement of each of the 32,510 measurements.

 

[Old Crow]

Next up is my new Noco G7200 charger on my F150’s Optima Yellow Top….


Background-

I must have been extra-good this year as Santa also brought me a G7200. It seems to operate very differently than my other chargers…. at least on the batteries I’ve tried.

I have a second Tundra, a 2002, and put the G7200 on its starter battery. But I couldn’t get it to start charging. The standby LED was on but I couldn’t get it into a charging mode. Pushing the selector button did nothing.

I contacted Noco Tech Support and learned the standby light will come on even if the charger isn’t connected to a battery so that’s not an indication of a good connection. Given the standby light, I hadn’t even thought to check my connection.

I also asked the agent about temperature. When the charger wouldn’t go on, I looked up operating temperature specs and they say it’s only good down to freezing. She told me the specs say that to prevent someone from trying to charge a frozen battery but the G7200 prototypes were tested in the coldest temperatures in Canada.

In the meantime, I had swapped in the CTEK to charge Tundra2’s battery so I took the G7200 to my F150’s Optima Yellow Top.

I connected it more carefully and this time the white charging LED came on. Battery-post temperature was only 18F so I switched to AGM/Cold setting.

I checked voltage with my multimeter and was surprised to see the voltage was only in the 12s. The blue LED was on and the 25% LED pulsing but still only 12s. I checked a few more times over the next hour and almost decided to pull it off as it didn’t appear to be doing anything, But since I had the logger watching, I thought I’d just let it run.

Here’s the plot… (sampling rate is one second)

(click to enlarge)



And here I zoomed in to a portion of it via the EasyLog software (so it would show scale better)

(click to enlarge)



Note— I don’t know when the G7200’s 100% LED went on. The 25% LED was still pulsing when I checked at 1630. When I next checked at 2045, the 100% LED was on and the multimeter showed voltage changing slightly every second.

 

[Vic Harder]

this is good stuff... Don't know that I know what it means yet... ;-)

 

[Old Crow]

I connected (and zip-tied) the EasyLog device to the battery of my 2013 Tundra this morning and drove off to run some errands.... (see plot below)

Background-

I bought the Tundra this past summer and noticed the alternator would put out 14.0 to 14.1 volts upon startup. As it warmed up, voltage would go down into the 13.6-13.5 range. And when idling I'd see it go as low as 13.3 volts.

Since then, two things have happened: (1) the weather has gotten much colder and (2) I installed a DC-DC charger to charge the house battery in my Hawk.

I don't think the change is from the DC-DC charger. I installed it in mid-October and my not-always-dependable memory tells me I was still seeing those low alternator voltage ranges after the installation.


Purpose-

This logging run was done to collect data on the voltages at the battery in today's low-20's temperatures. I believe the voltages are significantly higher than they were last summer (and wish I had a plot from back then to compare them).

Anyway, here's the plot. One-second intervals, zoomed in....

(click to enlarge)



Notes-

(1) The leftmost portion of the line is the battery voltage at about 12.2 volts after the logger started but before I first turned the ignition key.

(2) Voltages in the very high 13s to 14s are from the alternator (higher when driving, lower when idling).

(3) Voltages in the 12.7-12.8 range represent stops to gas up, visit the liquor store, the market, and a quick stop at the doctor's office to pick up a prescription. I'm surprised to see how steep the voltage drop-off is at each stop.

(4) I believe the voltage dips into the tens (and one into the nines) are the starter kicking in. The far-right dip is where I removed the logger from the battery.

(5) the very odd looking sequence just after 1230 hrs came from my shutting off the truck and starting it back up after I returned home.

 

[Vic Harder]

Is your starting battery an AGM? Factory unit? Have you replaced it before? Seems to me those voltages are more suited to a FLA battery, or the ECM is assuming the battery is fully charged and dropping into a float level voltage really soon. I would expect your AGM not so last very long.

In comparison, my GMC at -25*C is putting out 15+volts.

 

[Old Crow]

Is your starting battery an AGM? Factory unit? Have you replaced it before? Seems to me those voltages are more suited to a FLA battery, or the ECM is assuming the battery is fully charged and dropping into a float level voltage really soon. I would expect your AGM not so last very long.

In comparison, my GMC at -25*C is putting out 15+volts.

The one in that truck is a flooded lead-acid, i.e., a traditional wet-cell one with maintenance caps. It's a replacement made by Johnson Controls under the Autopart International brand. I see it has a sticker indicating date of manufacture as 11/2016.

Also - I've been trying to figure out why that battery seems to rest at so low a voltage. Right after getting the Tundra last summer I noticed the battery always seems to sit at 12.2-12.3v. I'd put the AC-DC charger on it and see 12.6 but within days it's back down. Hydrometer always seems to read in the lower part of the FAIR area at about 1.225 to 1.230. Cells are pretty consistent across them but the one nearest the negative post tends to read a bit lower by 10-15 points. I did an equalization run with the AC-DC charger but that didn't seem to change anything. It passes a 15-second load test (with the 130-amp version of one of those resistance-wire testers) but the needle is in the lower part of the green--- the lower 11s,
voltage-wise.

I thought I'd see it struggling in the colder weather but it had no problem starting the truck at -7F a few mornings ago... that was a surprise.

 

[Vic Harder]

interesting!