Smartgauge v MPPT regulator

[Justme]

I am not impressed with the efficacy of solar controllers

 

Stop buying cheap ones then.

[blodger]

Stop buying cheap ones then.

I am sure the one the OP has was not cheap but is lacking?

[Trev]

The cost of the regulator and separate digital display unit was just under 200 squid. Looking at other regulators they also have a cut off around 13.7 volts and at least one other forum member has similar problems to me. How many people rely on a regulator to give a soc reading for fully charged batteries? Without SG I probably would and end up with batteries only 80% charged. The sellers of solar regulators dont tell you that.

[WotEver]

The cost of the regulator and separate digital display unit was just under 200 squid. Looking at other regulators they also have a cut off around 13.7 volts and at least one other forum member has similar problems to me. How many people rely on a regulator to give a soc reading for fully charged batteries? Without SG I probably would and end up with batteries only 80% charged. The sellers of solar regulators dont tell you that.

A very good point. There are probably thousands of users wondering why they have premature battery failure.

 

Tony

[Grifter]

I must have exactly the same set up as Trev. This is an interesting topic. My understanding of the literature disagrees slightly with the info you got in your email from IVT. Here's what I believe is going on:

 

In the "main charging phase", the battery is charged with maximum current until it reaches 14.1V, then the battery is then held at 14.1V for several minutes in a "timer phase". After that, the controller enters a "charge maintenance phase" and applies pulses to the battery whilst holding it at 13.7V. The confusing thing for the observer is that the green "battery full" LED on the regulator comes on once the battery voltage has reached 13.5V in the main charging phase.

 

So if your batteries are getting taken to 14.1V before the controller drops the voltage, they should be getting closer to 100% SOC on the SmartGauge. I agree that it would be nice if the voltages were adjustable but it's probably not as much of a problem as it first seems. It would be even better for the controller to drop the voltage at 100% SOC but I'm guessing the reason they don't do this is the reason why a SmartGauge costs more than a voltmeter.

 

I've written a program to help me plot useful information from the data the monitor records. If you want to send it over, I'll run your data through it, to see how it looks.

 

Joe

[mickspangle]

I don't think I've ever had more than 13.7v at the batteries (as measured on the smartguage) even in bright Summer sunshine. Mind you I've never really had the batteries below 50% SOC.

 

Has anyone elses IVT mppt controller hit 14.1V? When the panels are working, Mine seems to be showing about 0.2-0.3V more on the SG than I would expect from the battery SOC.

[Grifter]

The data I recorded from the solar controller remote shows that the batteries are taken as high as 14.1 but the charging regime is not as clear cut as the literature would have one believe. Unfortunately, I've had to send back my remote for replacement, else I would have done a little experiment to see if it is doing what it is meant to. There is also some discrepancy between the voltages that the regulator remote shows and the voltage the SmartGauge shows, although this could be to do with voltage drop or calibration errors, etc. I'll have a proper look through my data to see if there's anything interesting tomorrow.

 

Joe

[macc]

some reading from my ivt last year.

 

2010.06.29 14:13:48 14.2 19.8 31.9 9.6 281.16

2010.06.29 14:13:59 14.1 17.7 32.8 7.9 249.57

2010.06.29 14:14:10 14.2 17.4 34.3 7.6 247.08

2010.06.29 14:14:20 14.1 16.8 34.3 7.3 236.88

2010.06.29 14:14:31 14.2 16.5 35.6 7 234.3

2010.06.29 14:14:42 14.2 16.4 35.6 7 232.88

2010.06.29 14:14:53 14.2 15.8 35.8 6.9 224.36

2010.06.29 14:15:04 14.1 15.6 35.8 6.7 219.96

2010.06.29 14:15:15 14.2 15.8 35.5 6.6 224.36

2010.06.29 14:15:26 14.2 15.6 35.5 6.6 221.52

2010.06.29 14:15:37 14.2 15.8 35.6 7 224.36

2010.06.29 14:15:48 14.2 15.1 35.9 6.3 214.42

2010.06.29 14:15:59 14.1 14.9 35.9 6.4 210.09

2010.06.29 14:16:10 14.2 14.8 36.1 6.2 210.16

2010.06.29 14:16:20 14.1 16.2 36.1 6.6 228.42

2010.06.29 14:16:31 14.1 15 33.7 6.3 211.5

2010.06.29 14:16:42 14 15.2 33.7 5 212.8

2010.06.29 14:16:53 14.2 16.8 36.2 6.4 238.56

2010.06.29 14:17:04 14.2 15.1 36.2 6.4 214.42

2010.06.29 14:17:15 14.2 14.7 35.1 6.4 208.74

2010.06.29 14:17:26 14.2 14.7 35.6 6.4 208.74

2010.06.29 14:17:37 14.2 14.8 35.6 6.3 210.16

2010.06.29 14:17:48 14.2 14.8 35.5 6.5 210.16

2010.06.29 14:17:59 14.2 14.7 35.5 6.3 208.74

2010.06.29 14:18:1 0 14.2 14.9 35.4 6.5 211.58

2010.06.29 14:18:21 14.1 14.9 35.4 6.4 210.09

2010.06.29 14:18:32 14.3 16.6 35.3 7.9 237.38

2010.06.29 14:18:42 14.2 15 35.3 6.6 213

[Grifter]

My program was more for looking at days, weeks and months of data to get daily averages and totals etc, but I plotted the data anyway. If you have lots of data, I'd be interested to see. I only have a couple of weeks. Your data shows that the battery is being taken as high as 14.1 and 14.2 volts.

 

Power into and out of the regulator. From this data, your regulator is, on average, 94% efficient. PDF link

 

 

A graph of panel and battery voltages PDF link

 

 

A graph of panel and battery currents PDF link

[Grifter]

These are a few of the plots I made from my data.

 

Average power produced in a day

 

Amount of energy produced in a day

 

On the 21st of August I had my engine running for quite a while, which is the reason for the low amount that day. None of the data I have proves what is happening as the batteries approach 100% SOC though. All I know is that if I leave the boat with no power draws for a day or two, when I return, the batteries will be at 100% SOC. When I get my monitor back, I'll see what I can find out.

 

Joe

[Gibbo]

What are you logging the data with?

 

Reason I ask is that I saw someone become obsessed with this a few years ago and he had a PC connected up logging it all and saving it to disk. Every ounce of energy he got from his solar panels, and more, got swallowed up by his PC

[Grifter]

Haha. This regulator and This monitor. Power draw of monitor at ~10V is 15mA and <1mA on standby (according to IVT's literature). Negligible, I think. It records data to an SD card, which I then copy to a laptop.

Edited September 7, 2011 by Grifter

[Gibbo]

...and This monitor.

 

I like that. A lot of functions for the money. Much better than that idiot with his PC.

[Semitrad]

Would a diode in the charger lead have the effect of raising the charging voltage? Same as the alternator bodge mod to the sensor lead.

[Grifter]

I don't think so. Quite the opposite perhaps. The voltage is measured internally by the regulator before the charging leads so putting a diode in the lead would reduce the voltage at the batteries. I don't know enough about electronics to start taking the innards of the regulator to pieces.

[Gibbo]

Would a diode in the charger lead have the effect of raising the charging voltage? Same as the alternator bodge mod to the sensor lead.

 

No it will drop the voltage. The other mod works by dropping the voltage in the sense lead so the reg thinks the battery voltage is lower than it really is.

[macc]

i did see 14.4v sometimes from the ivt but it would never get my batts to 100% soc so i replaice it with a invertek ss-50c http://www.richelectric.com.au/files/sunstar_mppt_series_manual_v10809.pdf batts are at 100$ soc by 14:00hrs with fridgefreezer running.

[Grifter]

invertek ss-50c

 

Looks like a clever bit of kit! How much was it?

[macc]

got mine from this seller of ebay http://www.ebay.co.uk/itm/Solar-mppt-charge-controller-50A-3400W-12-48V-w-logger-/130545635271?pt=UK_Gadgets&hash=item1e65204fc7 allthough from across the big pond itam came safley within 14 days,also got the shunt from him for £30.

[mickspangle]

So...OP what did you do in the end?

 

Macc...how are you getting on with your gubbins?

 

Me, I'm still wondering what to do. It seems like a 24/12V converter won't really help as they seem to output ~13.5V in any case. I think it might have to be a controller with an adjustable float voltage, but one that can handle 24V panels. ho hum.

[blodger]

So...OP what did you do in the end?

 

Macc...how are you getting on with your gubbins?

 

Me, I'm still wondering what to do. It seems like a 24/12V converter won't really help as they seem to output ~13.5V in any case. I think it might have to be a controller with an adjustable float voltage, but one that can handle 24V panels. ho hum.

 

The 24/12v converter seemed worse than a standard controller for a 12v nominal panel unsurprisingly really. Howver, I would have thought they would perform better or as well for a 24v nominal one. Yes they output at 13.5/13.7 about the same as most controllers but the latter shut off when that voltage is reached which was one of the problems to overcome since battry SOC was well below100%?

[smileypete]

So...OP what did you do in the end?

 

Macc...how are you getting on with your gubbins?

 

Me, I'm still wondering what to do. It seems like a 24/12V converter won't really help as they seem to output ~13.5V in any case. I think it might have to be a controller with an adjustable float voltage, but one that can handle 24V panels. ho hum.

One way for daily liveaboard use could be as follows, by having a batt bank that can be split in two.

 

The 'in use' half has the solar controller and all loads connected. The 'out of use' half is charged from the 'in use' half by a constant current/voltage (CC/CV) regulator like this, maybe in conjunction with a timer.

 

Then every day or so the solar controller and loads are switched to the other half of the bank. And the output of the CC/CV regulator is switched to opposite half of the bank which is now the 'out of use' half.

 

This means each half of the bank gets a guaranteed FULL charge every day or so. The CC/CV regulator just acts like a 'battery to battery' charger.

 

If you go away for more than a day or two, just switch off the CC/CV regulator and switch the solar regulator and loads to both halves of the bank.

 

I can post a simple diagram if that seems a little confusing.

 

cheers,

Pete.

[OldBawley]

Why mppt voltage drop ?

 

Bought an Mppt regulator for my solar panels. Did not listen to Noelex, so now I have a problem.

 

German made IVT 20 amp Mppt regulator. No means to regulate voltage, me stupid, not listen to Noelex. The regulator switches the solarpannels ( Two 85 watt in parallel ) extremely fast on and off so the voltage goes not higher than 14,1 V.

Unfortunately that is 14,1 Volt at the connections to the battery´s. I have a lot of voltmeters, they all show 14,1 V, but the one directly on the battery´s ( Mastervolt battman Ah/A/ V meter ) who takes his readings from a shunt mounted direct onto the battery´s reads 13,2 V.

Testing with a ( cheap ) multimeter conforms : 14,1 on electrical system, 13,2 on battery´s. ( During loading )

No way to crank the batt voltage up to 14,1 V.

Before I had the Mppt regulator the output of the panels was higher than now, have not seen any Mppt magic.

Furthermore, The battery´s are two years old, for me as a permanent non marina liveaboard that means 700 cycles. So the batts have suffered. Some sulfation.

When the regulator starts cutting down the currant / voltage at 14,1 V the Amp/ hour meter tells me some 15 A/h still need to be charged. Probably means 20 AH, no A/h meter calculates the loss of energy in transferring electrical power into chemical.

So the last 20 A/h are been charged at 2 to 3 Amps, not to exceed the magical 14,1 ( On the exit of the regulator ) That means then hours !

Why is there a difference in voltage between Out to battery´s regulator and the battery terminals?

Connected via 1meter of 6 mm outside cable and an Vetus three way battery switch.

[Chris Pink]

Why mppt voltage drop ?

 

 

 

 

Testing with a ( cheap ) multimeter conforms : 14,1 on electrical system, 13,2 on battery´s. ( During loading )

 

 

 

I am sorry but your post is almost unintelligible.

 

however the statement above implies a bad connection if your 14.1V and 13.2V are at two points only connected by wire. If you get 14.1 at some point in your system then, unless you have a diode in series, you should get that voltage at the battery terminals.

 

A quick test (of the connections) is to connect together, with a substantial piece of wire the points where you measure the two voltages and see if that raises the voltage at the battery terminals.

[Gibbo]

...no A/h meter calculates the loss of energy in transferring electrical power into chemical.

 

Most actually do.

 

Mr Pink, I would be almost certain in saying English was not his/her first language. There are several clues.