New to RVs and Hopeful Warp Core RoadTrekkers

[booster]

Your interpretation of the data appears to be wrong. It looks to me that you've mistakenly exaggerated the collective hourly results by a multiple of 7. The Volt Increase at 1 Hour s/b 0.35V, 2 Hour s/b 0.5V, etc. Over the entire day, you raised the voltage 1.06 volts.

The apparently tremendous loss of capacity while the modules were off during your restaurant lunch break needs to be investigated and explained. Perhaps you shut off solar charging at that time.

The sudden rise in voltage at the end of the day also needs to be investigated and explained. Was a load turned off?

It does appear that the spreadsheet simply added the voltage increases up, so dividing by the 7 readings would give the average voltage increase for the modules, which would be more useful in seeing how much increase in SOC there was.


The lunch thing is tough to figure how much loss there was, as it is in the flat part of the charge voltage curve, but any loads should be able to calculate it. Maybe it was because the modules were turned off during this time to prevent parasitic loss?

 

[markopolo-ClassB]

It appears that the OP just posted what he observed. What do you base your post on? Did you make your own observations? If not present during the OP’s test; why would you feel free to use hyperbole to to denigrate his post? Do you have a crystal ball?

Keep it real; be polite.

You've asked 4 questions and I don't understand what it is that you are asking.

What, specifically, do you see as hyperbole?

 

[markopolo-ClassB]

It does appear that the spreadsheet simply added the voltage increases up, so dividing by the 7 readings would give the average voltage increase for the modules, which would be more useful in seeing how much increase in SOC there was.


The lunch thing is tough to figure how much loss there was, as it is in the flat part of the charge voltage curve, but any loads should be able to calculate it. Maybe it was because the modules were turned off during this time to prevent parasitic loss?

I think that adding voltages like that is meaningless. This is the chart on WingedRyno's website:





It was actually a slow and steady increase in system voltage and not the wild swings shown in the chart.


The lunch thing -

The dip in the middle was due to measuring the batteries that had charged for four hours after coming back from a two hour lunch at a wonderful cafe on Lake Superior (the batteries were turned off during our lunch).

If we assume battery capacity increased by 160ah in the hour before lunch the the data presented could be interpreted to show that 160ah was lost during the lunch break (with the modules turned off) if we choose to use the reported system voltage to represent SOC.



All of the voltage gain between the 3hr and 4 hr points was lost during the lunch break. That doesn't even include solar input ............

 

[WingedRyno]

Your interpretation of the data appears to be wrong.

That is VERY possible.

It looks to me that you've mistakenly exaggerated the collective hourly results by a multiple of 7. The Volt Increase at 1 Hour s/b 0.35V, 2 Hour s/b 0.5V, etc. Over the entire day, you raised the voltage 1.06 volts.

I didn't exaggerate as I think that would require purposefully twisting the numbers. Mistakenly? Certainly possible.

I took the individual voltage gains and added them up rather than adding the collective voltage differences. Why? I just picked one and figured individual voltages were more likely to be the more accurate. Either way, the average of the collective voltages was pretty much the same as summing the individual increases although it was a bit different on the third hour associated with 13.3 volts which I think I made an effort to highlight in my blog post (the disparity between the average of the collective versus the individual voltages). I don't see a big issue here but if you do please explain. From my vantage point it's interesting but not particularly important.

The apparently tremendous loss of capacity while the modules were off during your restaurant lunch break needs to be investigated and explained. Perhaps you shut off solar charging at that time.

I thought I explained why I think that occurred in my blog post. I did not shut off solar (not sure how to do that) and I *think* my solar is not working at the moment although that's my next test and area of investigation, figuring out our solar and exactly how it's working.

As I tried to say in my blog post, I think the dip from before and after lunch is because the volt meter displays voltage that includes draws and charging and when those loads or charging sources are removed, the voltages tick down to something more stable and accurate. So as soon as the ignition is switched off and the GU is turned off, the volt meters shows a big drop instantly. It then ticks down over the next couple of minutes. After about two minutes I took a reading because I didn't want to wait much longer than that. I suspect that it takes longer than two minutes for it to tick down to its more stable voltage and I suspect that is what happened over the lunch break.

After this test I turned off all seven EcoTreks to see what they would read in the morning and to see if they would show a lower voltage like occurred over the lunch break. They did show lower and I updated the blog post to include that info.

The next morning EcoTreks 1-7 read 13.71, 13.78, 13.77, 13.78, 13.71, 13.78, 13.73 volts.

The sudden rise in voltage at the end of the day also needs to be investigated and explained. Was a load turned off?

The only load during charging was the fridge/freezer and all my readings were taken after shutting down the GU and turning off the frig/freezer and waiting about two minutes for the voltage to stabilize. That was true at the end of the day just as it was for all readings.

 

[WingedRyno]

I think that adding voltages like that is meaningless. This is the chart on WingedRyno's website:


View attachment 5810


It was actually a slow and steady increase in system voltage and not the wild swings shown in the chart.

That chart shows the system's total added voltage by adding up the voltage increases of each module. What the data means if anything, I'm not really sure yet because volts are not amps. It does show, for whatever if anything it's worth, that more volts are added into the overall system when charging more than one EcoTrek at a time. That was useful for me because "voltage" is the best and only thing I have at my disposal to see when batteries are "fully charged" and since I am interested in charging my batteries to full as quickly as possible and with the least amount of diesel burned, it meant something to me. Your mileage, pardon the pun, may vary.

The lunch thing -

If we assume battery capacity increased by 160ah in the hour before lunch the the data presented could be interpreted to show that 160ah was lost during the lunch break (with the modules turned off) if we choose to use the reported system voltage to represent SOC.

All of the voltage gain between the 3hr and 4 hr points was lost during the lunch break. That doesn't even include solar input ............

I don't think equating to volts and amps like that is useful. Outside of "near empty" and "near full" I'm not sure we know what voltage corresponds to the SOC and amount of amps sucked up by the battery. At least I don't know.

My solar I don't think is working which ironically helps this test. But I haven't confirmed it. I did this test awhile back though which makes me think it's not working, I need to confirm it though.

https://convotrek.blogspot.ca/2017/09/solar-charging-stopped-working.html

 

[cruising7388]

My solar I don't think is working which ironically helps this test. But I haven't confirmed it. I did this test awhile back though which makes me think it's not working, I need to confirm it though.

Do you have the MT50 remote display for the solar controller?

 

[WingedRyno]

Do you have the MT50 remote display for the solar controller?

No. I just have two solar charge controllers with lights that flash to show when charging, and when the batteries are full. But I have noticed that one of my solar charge controllers will flash that the batteries are full while the other does not. I thought they might be charging different batteries, but the tech at the factory told me they both charge all batteries.

 

[cruising7388]

No. I just have two solar charge controllers with lights that flash to show when charging, and when the batteries are full. But I have noticed that one of my solar charge controllers will flash that the batteries are full while the other does not. I thought they might be charging different batteries, but the tech at the factory told me they both charge all batteries.

Is your solar controller(s) model the Tracer 3215-BN?

 

[WingedRyno]

Is your solar controller(s) model the Tracer 3215-BN?

I don't know the model off hand but they are both Tracers as shown here.

 

[markopolo-ClassB]

I used exaggerate as in overstate. I didn't think for a minute that there was any intention to mislead. I still don't understand why one would add up voltages like that but if it helps you then great.

I didn't know the testing parameters and assumed solar would be working over your lunch break unless you turned it off. I agree that the settling of the voltages could explain part of or all of the dip. If you test again then perhaps apply and remove a momentary large load like a hair dryer to get a more accurate reading.

The most fascinating bit of data (to me) is the rapid finish from around 95% SOC to full. That part takes a long time with lead acid batteries.

 

[WingedRyno]

I used exaggerate as in overstate. I didn't think for a minute that there was any intention to mislead. I still don't understand why one would add up voltages like that but if it helps you then great.

Right on, yeah I could easily be messing something up. In fact I'd say it's likely. I'm by no means competent let alone an expert in this stuff.

But adding up voltage increase is the only way I know of to gauge the efficiency and speed of charging these EcoTreks. Can you suggest a better method to do that? I would love to have SOC information but I don't have access to it, so given what I have to work with, adding up voltage increases over time is the only way I know of to get an idea of what charges the batteries the quickest.

 

[booster]

Right on, yeah I could easily be messing something up. In fact I'd say it's likely. I'm by no means competent let alone an expert in this stuff.

But adding up voltage increase is the only way I know of to gauge the efficiency and speed of charging these EcoTreks. Can you suggest a better method to do that? I would love to have SOC information but I don't have access to it, so given what I have to work with, adding up voltage increases over time is the only way I know of to get an idea of what charges the batteries the quickest.

Somebody on here posted an approximate but close (claimed) chart on SOC vs voltage that would be what you need. All you would do was add a column to your chart for SOC after taking the readings off the chart. You could do each module individually or just look up the SOC for the average voltage which is your number for added up voltages divided by 7.

 

[cruising7388]

I don't know the model off hand but they are both Tracers as shown here.

How much solar do you have?

 

[WingedRyno]

How much solar do you have?

610 watts with one large panel wired into one charge controller and the other smaller panels wired into the other. Was told both charge controllers are wired into a terminal for all batteries.

 

[WingedRyno]

Somebody on here posted an approximate but close (claimed) chart on SOC vs voltage that would be what you need. All you would do was add a column to your chart for SOC after taking the readings off the chart. You could do each module individually or just look up the SOC for the average voltage which is your number for added up voltages divided by 7.

We got this chart from the RoadTrek & Hymer Owners FB group (great group). Once we get our monitoring system and AI algorithms crunching the data I think we'll be able to produce a pretty tight chart.

https://convotrek.blogspot.ca/2018/05/gu-charging-one-ecotrek-to-full.html

 

[GeorgeRad]

We got this chart from the RoadTrek & Hymer Owners FB group (great group). Once we get our monitoring system and AI algorithms crunching the data I think we'll be able to produce a pretty tight chart.

https://convotrek.blogspot.ca/2018/05/gu-charging-one-ecotrek-to-full.html

I am a little late in this subject but am struggling to understand what is the objective of this exercise, what do you want to know?

SOC measurement is the best way to measure batteries charge levels using a shunt meter capable to continuously calculate a sum of charging and discharging currents, can you invest into a right tool?

 

[WingedRyno]

I don't think that's an option for RoadTrek EcoTreks. Would love to be wrong.

 

[GeorgeRad]

I don't think that's an option for RoadTrek EcoTreks. Would love to be wrong.

Do these Ecotrek batteries have a common ground, they should, just can’t imagine how would they wire their batteries without one. Just by a Victron 7XX meter or equivalent, place it between Ecotreks and ground and you get an overall SOC meter.

 

[markopolo-ClassB]

Booster - did you end up using Hall Effect sensors to monitor alternator output? If so, maybe that is a good and not too invasive or difficult way for WingedRyno to know that he is fully utilizing the alternator. I get the impression that he is more concerned about effective charging than SOC. If the amps start to drop then turn on more modules.

Or, can alternator output be obtained from the Balmar unit?

 

[gregmchugh]

Do these Ecotrek batteries have a common ground, they should, just can’t imagine how would they wire their batteries without one. Just by a Victron 7XX meter or equivalent, place it between Ecotreks and ground and you get an overall SOC meter.

In any case, an external shunt based monitor can not measure the internal power being used by the BMS and it’s associated electrical loads which can be significant for the Ecotrek modules.

You could also have a complication due to the fact that the individual Ecotrek modules can be offline and online, I would have to think about how that would effect a battery monitor measurement of SOC.

You might also need to have the capability to manually reset the battery monitor 100% SOC point which, as I recall, is sometimes triggered automatically when the monitor sees the charge current drop below a set value. Not sure if that feature is available or not.

And, if there is a way to have multiple grounds for the battery bank, Roadtrek probably did it...