Operating Observation CL 150 vs MX60

[Westbranch]

Last fall I placed my 2 24v 1800# batteries in the basement (Phew!).
Having no PV up at the time, I gave both a boost charge with the charger, for their winter rest. 
Both were charged for ~ 4 hrs each till they went into float < 5%Charger amps (1.5A).
This was followed up the next weekend with a similar routine but it only took 1 hr to reach float (no loads) and they got another hr of float time.
In March I managed to get in and set up 2-120W panels (24v) and hooked up the MX 60 to battery 1. It ran for a month before I got back. As expected it was hitting Float in about 1 hr when the sun was full-on the panels.  Hooked  CC up to Battery 2.   
Another month passed till I got back in (at Easter).  Battery 2 now had same pattern as #1. It hit Float after 1 hr of full-on sun...
This time I brought a CL 150 and hooked it up to battery 2 and the MX back on battery 1.
Charge parameters set as close as possible on both CC's

There is a very slight difference in the power getting to the 2 CC's,
batt 1 has 2-120W at summer angle ~ 45*,
batt 2 has 2-140W in Vertical orientation.
Both CC's read the same for PVin  Volts, with a minor Amp difference.
Panel to CC distance is the same.

What I observed is that the MX reaches float and then "snoozes" while the CL150 stays in Float  for the rest of the day...
Any ideas why there is a difference?  Just the algorithms of each charger?

[Vic]

Hi Wb,

My experience with MXes is that once the Abs stage is complete,  they always go to Float,  and remain there until there is too little current avaialble to maintain Vfloat.  At that point,  the MX transitions into F-MPPT,  and remains in this condition until there is just too little current available to justify running the Converter,  at which point,  the MX Snoozes or Sleeps.  IIRC,  after an extended period of Sleeping the stage is displayed as, "Zzzzzz",  or similar.

One  MX here has 5.10 FW,  and the other is 5.11.

Wonder is perhaps that since (guessing) that the only loads on the batteries are the batteries themselves,  and believe that they are AGMs,  that perhaps there is so little current needed from the CC that PERHAPS the MX chooses to snooze until there is some real current needed ?  Perhaps you could place some load on the batt terminals to see if the MX supplies the required current ...

I dunno,  the banks that have been/are charged from MX-60s here are FLAs,  and normally require about four amps of output current from the MXes to run the inverters plus parasitic loads and maintain Vfloat,   so there is some work for the CCs to do.

Guessing done for now,   Vic

[boB]

If you are seeing "snoozing" on the MX60, that usually means there was too low of
output current (set in the advanced menu for around 1 amp or less) and the MX
is waiting 5 minutes to wake up again.   But if another charger source is
providing the Float voltage to the batteries, then you only need that one
source to do that.  More chargers in Float is just a waste of energy.

You can try to wake up the MX in the MISC menu and press wake if it still
has that feature.

boB

[Westbranch]

If you are seeing "snoozing" on the MX60, that usually means there was too low of
output current (set in the advanced menu for around 1 amp or less) and the MX
is waiting 5 minutes to wake up again.  But if another charger source is
providing the Float voltage to the batteries, then you only need that one
source to do that.  More chargers in Float is just a waste of energy.

You can try to wake up the MX in the MISC menu and press wake if it still
has that feature.

boB

Nope, just one charger per bank.

Will try the 'Wake-up' next visit and also check the Advanced menu settings

Thanks.

[Vic]

You can try to wake up the MX in the MISC menu and press wake if it still
has that feature.
boB

The MXes that have been in use here have 5.10 & 5.11 FW (5.11 is the last update available).

In the Misc Menu,  the right button on the first page is "Rstrt",  which seems to "awaken" the MX,  FWIW.

Do not recall seeing a Wake function in either of these FW versions.  Did not start using MXes until 2005,  so the view of history here,   is not too deep.   Vic

[boB]

You can try to wake up the MX in the MISC menu and press wake if it still
has that feature.
boB

The MXes that have been in use here have 5.10 & 5.11 FW (5.11 is the last update available).

In the Misc Menu,  the right button on the first page is "Rstrt",  which seems to "awaken" the MX,  FWIW.

Do not recall seeing a Wake function in either of these FW versions.  Did not start using MXes until 2005,  so the view of history here,   is not too deep.   Vic

Yeah, that's it.  It used to say wake at one time I think.

boB