More mt50 settings...

[robstrom]

My system ( 820 watts on roof,epEver 4215bn, SOK 206) is alive!! No fires or electrocution!! It all works.
Question: Ran battery last couple weeks for small stuff. Yesterday got live, n it charged to full.
Today, I'm using it for stuff.
Bright sun, n mt 50 indicates not full/ blinky green .
Solar is zero amping, mt50 shows 13.1 volts battery.
When/ how/ which setting puts charging back on??
1 battery: there's charge limit/ equalisation/ boost/ float/.
Seems I'm the only one who isn't retrofitting to LFP.
I built this system AROUND the battery.
Tips??

 

[fratermus]

Bright sun, n mt 50 indicates not full/ blinky green

The green light on the MT50 indicates a connection to the controller (communication, hence the COM label), not charging status.

Charging stage is visible from the Battery screen (hit right-arrow 2x), or can be deduced by watching bank voltage vs. panel voltage (see link below).

Solar is zero amping, mt50 shows 13.1 volts battery.

Sounds like it's floating, assuming that voltage is similar to where you have Float voltage configured. If you post a pic of the MT50 display when this is happening and how you have it configured up we'd know more.

When/ how/ which setting puts charging back on??

I'm not sure what the question means.

Solar systems only make power when required, which can surprise folks who are new to solar. If no power is required to hold Float voltage or Absorption voltage or whatever then no power will be made. Lithium has such low self-discharge that it can sit unloaded at a particular voltage with no help from solar.

If you want to see the system make power then drop a big continuous load on it when the sun is out (preferably local solar noon) and watch the meter while that happens. 4:1 panel:bank ratio and Lithium's low internal resistance means that you could run a power tool and by the time you got back to look at the meter the bank could be 0-amp at Vfloat again. Slurrrrrrrrp!

If you are asking "which setpoint controls the restarting of Absorption" that is the "Boost Reconnect" setpoint.

Seems I'm the only one who isn't retrofitting to LFP.

It's a function of "seat time". The people who are retrofitting (or still running Pb) were running solar before LFP came to market.

Tips??

Now that the system is running I'd relax with a cold beverage and re-read the manuals. There are some translation issues but in general they cover a lot of ground.

BN-series manual
MT50 manual

 

[robstrom]

Sorry, I meant pv and battery indicators on the charge controller
Loads WILL be light, generally.
Biggest load is inverter (of course), a 600 watt samlex, powering a 2 door fridge/ freezer that that only uses 65 watts running. LED strip lights/ 12 volt roof vent/ fan.
Changed some settings, it's clearly in float mode.
I'm trying to keep the battery in the 85-90% range, rather than fullfull.
Charge limit is 14.2 (3.55 x 4).
If anyone has a link/ resource that translated battery voltage for LFP to approximate %, that would be handy.

 

[pollenface]

I only use my MT50 for adjusting settings. I disconnect it and put it away when not in use, that's an extra 0.5a parasitic drain

What is your float and boost reconnect voltage currently set to?

 

[fratermus]

an extra 0.5a parasitic drain

According to the specs the MT50 consumes less than 15mA when it's sitting there with the backlight off, not 500mA. I leave mine plugged in as ~15mA doesn't seem worth the wear and tear on the jack and connector. Everybody's situation is different, though, and I can imagine a scenario where 15mA is meaningful.

If anyone has a link/ resource that translated battery voltage for LFP to approximate %, that would be handy

The voltage discharge curve is so flat that it's difficult to gauge SOC from voltage until you reach "the knees" where it rises/falls sharply. An coulomb-counting meter may prove more useful. Having said that, see this info put together by @Steve_S here on the forum.

 

[pollenface]

According to the specs the MT50 consumes less than 15mA when it's sitting there with the backlight off, not 500mA. I leave mine plugged in as ~15mA doesn't seem worth the wear and tear on the jack and connector. Everybody's situation is different, though, and I can imagine a scenario where 15mA is meaningful.

I stand corrected.