TRIStar MPPT 45 Custom Settings with switches 6-7-8 set to on-on-off

plc-solar-guy

I have been experimenting and building an Off-Grid system to run a variety of equipment during the day and night. The system works well except the Charge Controller always goes into absorption mode regardless of the charge state that it has seen after leaving it's last absorption session. I have asked tech support and was politely told to look at using custom settings. I have 5, 12 volt sets of 420AH L-16's. They have both a direct path to charge controller or they be charged via a diode path that lets them charge independently. The whole system is manged by a PLC that controls usage and charging based on AMP-Hours drawn and other parameters. I have monitored and charted the 24 hour and 48 hours charge patterns, via MSView, and no matter what I do it goes into absorption mode when it is able to start charging after being in night mode. During night mode the battery voltage stays above 12.70. I have not been able to find much information on the units default setup for the L-16 settings. It also has many other configurations via setup. Does anyone know where I can find more information on the MPPT custom settings? Thanks for any help in advance.

Photowhit

Re: TRIStar MPPT 45 Custom Settings with switches 6-7-8 set to on-on-off

So do you run any loads during the night? very odd to have an idle battery at 12.7+ with any loads as that represents a fully charged battery.

I'm use to my charge controller going rapidly into absorption, and that is the stage it should be in if your battery is at 12.7 over night, and even moving rapidly into float.

Battery FAQ's

plc-solar-guy

Re: TRIStar MPPT 45 Custom Settings with switches 6-7-8 set to on-on-off

Photowhit wrote: »

So do you run any loads during the night? very odd to have an idle battery at 12.7+ with any loads as that represents a fully charged battery.

I'm use to my charge controller going rapidly into absorption, and that is the stage it should be in if your battery is at 12.7 over night, and even moving rapidly into float.

Battery FAQ's

Thank you. I agree with you, I too am used to seeing the charger go into absorption mode. Yet there are times that charging only one or two lightly used batteries in absorption mode is not an efficient use of the charger. There are conditions, depending upon what the load criteria is, and what is requesting power that I would like to keep a newer battery set on line and charge the others via the diode path in float mode. When conditions warrant, weekend are different than weekdays etc, or when all batteries have passed their designated amp hour usage levels the system can release load and allow the controller to see voltages below 12.50 and trigger absorption mode.

The problem is that I cannot keep the charge controller from going into absorption mode after entering night mode and presenting the controller all night a steady voltage above 12.50 (The manual stated float violation voltage). The system count days and cycles to make sure equalizing occurs on a set period. All this is from field testing and actual use data.

niel

Re: TRIStar MPPT 45 Custom Settings with switches 6-7-8 set to on-on-off

i see a problem here in that you are trying to charge multiple banks of 12v l16 strings and some are isolated with a diode. charge controllers will draw the power for self operation from the battery strings that aren't going through the diodes. this would also be a voltage sampling unless you opt to use the remote voltage sense on the tristar, but this is only good for reading either 1 set of the isolated batteries or the batteries not isolated at all. doing this through a diode presents a voltage drop of .5v to .75v meaning if one set is charged properly that the other is either staying under or over the proper voltages for charging.

it is my opinion that you should be employing separate controllers rather than trying to diode isolate the battery banks. of course i don't recognize what plc stands for off hand.

stephendv

Re: TRIStar MPPT 45 Custom Settings with switches 6-7-8 set to on-on-off

As you've found out, there's no way to prevent the tristar from going into absorb every day- your best option is just to set the absorb time to something short, e.g. 5 minutes.
There are 2 other settings that can also help out with your setup: Absorb extension voltage and float cancelation voltage:
- Absorb extension will add on the specified time to the normal absorb settings if the batteries dip below the specified voltage, e.g. absorb extension could be 2 hours and absorb extension voltage could be 12.5V. So if the batteries are really fully charged, then won't dip below 12.5 so will only go through a 5 minute absorb (which is good in any case to mix the electrolyte up a little).

- Float cancelation voltage is a bit misleading it refers to the voltage where the controller will ignore float for the following charge cycle and will instead stay in absorb for the whole day. E.g. if float cancelation is set at 12.2V, then if the batteries dip below that value during the night then the following day there will not be a float cycle- the batts will stay in absorb.

plc-solar-guy

Re: TRIStar MPPT 45 Custom Settings with switches 6-7-8 set to on-on-off

Thank you for the reply. I do run loads at all times of the day and night. I may be wrong but I have found, after a lot of testing, I can accomplish charging and running a variety of loads by controlling the chargers and the inverter loads ( rather than they controlling me. A PLC is a programmable logic controller [ http://en.wikipedia.org/wiki/Programmable_logic_controller ]. By controlling what is charging and what is drawing current, I can have dissimilar batteries and dissimilar amp hour states among the batteries yet keep everything balanced over a given time period. I know that I may be out there, but it looks promising.

plc-solar-guy

Re: TRIStar MPPT 45 Custom Settings with switches 6-7-8 set to on-on-off

Thanks so much for this information!! It helps explain whats going on. Besides the little information I have found on the Morningstar technical section are there any on-line documents that explain the other sections of the custom setup ? I will experiment with this new information. It should help a great deal! Thank you again for your help!!

Photowhit

Re: TRIStar MPPT 45 Custom Settings with switches 6-7-8 set to on-on-off

You might search for "tallgirl" I think she has done some custom software for outbacks (I may have everything wrong here, but a mod should be able to clarify.)

I always feel that you do better with a single bank, and higher voltage, so even considering 5 strings at 12 volts is plenty 'out there' for me.

BB.

Re: TRIStar MPPT 45 Custom Settings with switches 6-7-8 set to on-on-off

Here you go:

Julie in Texas

greenMonitor(tm) for Morningstar, OutBack and SMA from greenHouse Computers.

-Bill

stephendv

Re: TRIStar MPPT 45 Custom Settings with switches 6-7-8 set to on-on-off

plc-solar-guy wrote: »

Thanks so much for this information!! It helps explain whats going on. Besides the little information I have found on the Morningstar technical section are there any on-line documents that explain the other sections of the custom setup ? I will experiment with this new information. It should help a great deal! Thank you again for your help!!

The manual covers all of the settings: http://www.morningstarcorp.com/en/support/item.cfm?ItemId=414

Coach Dad

Re: TRIStar MPPT 45 Custom Settings with switches 6-7-8 set to on-on-off

I just went through this same exercize.
I set my Tri Star MPPT to Absorb for 30 min every day and do a 90 min extension only if the battery drops below 70% SOC
You can pick your own numbers but you will have to use the custom settings WITH their free MSVIEW software

You can get the MSView software here
http://www.morningstarcorp.com/en/support/results.cfm?LibraryId=3

The help file in the software does a pretty good job of describing each setting.