Kid vs Tracer

[tecnodave]

Robin, Mario and the group,

I have promised a head to head comparison of the MidNite Kid verses the EP Solar Tracer so this is the results on many head to head comparisons.

It's no fair bout, the Kid won every round.

First off the Tracer is crippled by the fact that the output voltage cannot be set to match the battery so it cannot be closely coupled with the battery like the Kid can be. On L-16's it is not possible to fully charge them as the Tracer is set way too low a voltage so specific gravity never exceeds 1.220 whereas the Kid pulls it up to specs. , 1.265.  Same deal with 3050's , never get to full charge.
Group 27 automotive/deep cycle batteries the Tracer faired a bit better as these use a somewhat lower charge voltage.

One test involved two identical batteries , Interstate Brand MTP-65 batteries  that were discharged to 35 % SOC then connected one to tracer and one to Kid , both were fed with identical arrays consisting of two banks  of four series connected Siemens SM-55  68.8 v @ Pmax. 440 watts each array.

This test was run in 4 hours and kid's battery had about 5% more SOC than the Tracers battery.
The Kid was set at U.S.Battery,s recommended voltages

This test was the closest the tracer was able to get to the output of the Kid.

Another series of tests was done with a "battery" which cannot be charged!  I used a Hewlitt-Packard lab grade bench power supply source/sink. This is a bit different than a normal power supply as it can source or sink power. It was set to 11.800 volts to simulate a very dead battery. This unit can output 100 amps but can also absorb 100 amps as a sink ,so it's a perfect "unchargeable battery".
I borrowed only one of these so the Kid and Tracer outputs were connected to gather at the power source. Each had its own set of identical panels.

Set one.      8 each monocrystal hooked series/parallel   34.4 v @ Pmax.      440 watts
Set two.      8 each monocrystal hooked series.              68.8 v @ Pmax.      440 watts
Set three.     1 each polycrystalline                               35.2 v @ Pmax.       280 watts
Set four.       5 each CdTe.    In parallel.                         69.2 v @ Pmax.      375 watts

Only one set of panels were used at a time.  Each set is two identical arrays
Starting very early in the day after a looong nite setting everything up

Both controllers are "seeing" a very dead battery so both are forced into bulk MPPT mode and maximum charge rate.  Early was very clear and sunny and both controllers were neck and neck pretty much at 88 to 92 percent conversion rate then some low crowds scudded in off the Pacific Ocean and a huge gap opened up!!! Both controllers would do a MPPT sweep but the Tracer would take 30 to 90 seconds to complete a sweep where the Kid was under 2 seconds also in varying cloudiness the Kid was sweeping easily 5 times more often than the Tracer. Net result: the Kid left the Tracer in the dust........collected about 35% more power in rapidly varying conditions.

Test was repeated next day with much the same results but the weather was clearer and the results were closer. Still the MPPT sweep algorithm difference was very apparent.

Testing continues as these controllers are in daily use here.
The Tracers are only backup use and supplemental for when my summer coastal fog rolls in. At that point all controllers and panels are connected.

Test equipment used:

Fluke 23 DMM (industrial 77). Current cert
Fluke 87V.  Current cert.
Tectonics 2465 oscilloscope  (4channel, 350MHz, dual trace). Current cert.
Simpson 260-5 analog voltmeter. Current cert
Fluke 52 dual channel J/K thermocouple driven thermometer. Current cert
Snap-on MT-540 Automotive analyzer field calibrated to Fluke 55000 lab calibrator (no cert)
(8" Analog high accuracy ammeter, voltmeter and carbon pile load tester)

I do have calibration lab experience and have access to lab grade instruments.

td

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[boB]

Thanks for the review, Dave !   Nice to see your comparisons !

Sounds like that sourcing/sinking power supply is very cool, too.
Are those old and found on E-bay at all I wonder ?

boB

[dgd]

Just wondering which model of Tracer you were using in your testing?

I wanted to do the same sort of testing and working with equal $ value of products.
The non-marine KID sort of lines up against the ET3415N 30amp Tracer or even the ET4415N 45amp Tracer.

I decided to delay this comparison until the KID firmware was developed to include most of the features mentioned when it was released. Also until it gets more debugged.

But just on build quality alone the KID feels the better and the KID's 2 line LCD/keys sort of feels superior, but then I'm a biased Classic owner 

dgd

[ClassicCrazy]

Techno Dave - I think in one of the other posts you hadn't updated the firmware - which firmware was this test for ? 

[tecnodave]

DGD,

I am using a Tracer 3215RN , the models you are referring to are eTracer units from the same company. The eTracers are much more advanced units which are programmable and have more features. I paid $190. USD for the tracer and $40. USD for the remote controller vs the $200 I paid for beta kid.

CC

I am still using first beta firmware, kid does not tell me which version. I did not update due to not having a winders machine. I'm still looking to do that.

td

[Vic]

td,

When the battery breaker is first closed,  and the KID is booting,  the Firmware version should be shown on the LCD.    At least on mine,   it is this way.    FWIW        Vic

[dgd]

I am using a Tracer 3215RN , the models you are referring to are eTracer units from the same company. The eTracers are much more advanced units which are programmable and have more features. I paid $190. USD for the tracer and $40. USD for the remote controller vs the $200 I paid for beta kid.

td,

I suppose you did a 'like value' comparison but the $200 beta KID pricing vs the street priced 3215RN+RT1 is a special unrepeatable case.

When I looked at this the 30A eTracer with all up UPS delivered price to me of $359 from Aliexpress was comparing to the best delivered price of a KID from AltE of over $414.

Without the shipping costs these prices were 30A eTracer $245 and KID $290, the 45A eTracer was $285.

As you say the eTracers are quite advanced units with ethernet,RS232 and Canbus interfaces and seem a pretty close match on overall features to the KID.
But not really in same ballgame as the Classics.
The potential for the KID to manage a wind system and its LOAD interfacing is expanding it beyond the PV only eTracers.
If it just had some interfacing for reporting... or a combox for IP or serial connectivity....

dgd

[tecnodave]

Vic,

My kid only displays :          MidNite Solar
                                            The KiD

Then goes right to status,  I have searched the menu's , the case inside and out, and the packaging and paperwork ....alas no serial number and no firmware rev. Number.   As I mentioned I was on line when Robin first posted and was first to ask for the beta unit so I am assuming that I have a very early beta unit. If I had known the kid was coming I probably would have not bought a Classic, but having more than one controller when totally off grid is not a bad idea and the Classic was a very good purchase as now I know just what a good controller can do.


DGD,

I did not do a like value comparison, only what I have experience with, also is saw the tracer line as the biggest competitor to the kid. I had been using the tracers for two years and write about them at Amazon.com.  FYI, the tracer also has CANBUS over RS-232 to communicate to the remote although EP Solar will not confirm that or any details about it. I did get a chance to review a eTracer 6415 and it has the same very slow MPPT tracking algorithm that is used in the tracer...very slow!!...45 seconds to  >1minute at zero power while doing MPPT sweep and the resultant calculations. The Classic and kid do this so fast I use my scope to time it. Also the programming for determining when to do the MPPT sweep is way inferior to Midnite's programming.  I live only 6 miles from the Pacific Ocean as a result I have rapidly changing weather patterns and cloud cover and the fast algorithms used in MidNite products is very apparent.

I have had the eTracer 6415 side by side with a Morningstar TS-MPPT-60 and it is very apparent to me that the eTracer is a reverse engineered product. It is so close in features it is obvious. Parts of the manual are exactly copied from the Morningstar product. Look at the battery charging charts and tell me that is not copied...down to the detail.

In any case my big disappointment with EP Solar is that they do not respond to inquires about their product. No support, no user group that I could find except that found on Amazon, which is mostly newbies.

In any case this is a learning process to me as well even though I worked with solar panels in the early 70's while an engineer in the two-way radio field as our radio repeaters were on the tallest mountain to be found. Communications was the first adopter of solar, first in space then remote communications sites. I am still using some of the original Arco panels that I installed back then.
They are the 50 watt square cell design made in Camarillo, Calif. still producing full power! All of my Siemens panels first did duty at communication sites. Back then we used big Zener diodes as over voltage controllers, there were no advanced controllers available, only shunt controllers, and smoked batteries.

My hugest breakthrough was to find this forum and NAWS where there a bunch of avid users are sharing so much!   Thank you MidNite and NAWS!

td