To Keep or Not To Keep? AGM

pthomas745

@rh5555 One thing we don't know is how the Alde handles battery monitoring.  How does it sense the battery state of charge?  How much is it affected by the "rested" battery issue?   Will it monitor a lithium battery correctly? That 10.5 volt number comes out of the manual, I'm sure there are plenty of "real world" variables. 

The Alde manual, when it describes the "Low Voltage" error, says this:

Low battery: 12V supply to hydronic heating system has dropped below 10.8V, possibly causing system brownout. This message clears automatically when the current reaches 11V. If the voltage decreases, various error messages can also appear. These are not actual faults. Ensure that the furnace has the right voltage.

This "system brownout" is what you were experiencing.  Also note it says "various error messages can also appear".  Which is probably what RH5555 had with the low voltage.  (Another very confusing Alde manual comment!)

And, I noted the Alde 10.5 volts is required for the Alde to operate.  The manual (page 4) says that 10.5 V number would "shut off the gas supply".  So, there appears to be a "twilight zone" for the Alde between 10.8 volts and 10.5 volts. 

But: since you do have good monitoring happening on your batteries, something else may be drawing your battery down, or, they are failing.  Check carefully the status of your inverter:  it is a constant draw if it is left on.

otr_320

Where you measure voltage while troubleshooting the Alde low voltage problem could be important. Ideally the voltage should be measured at the Alde unit itself.  Although the battery terminals or Victron shunt may measure x number of volts, this doesn't necessarily mean the Alde is receiving the same x number of volts.

Before we upgraded some of the battery to powercenter wiring on our '23 320, the OEM wiring was causing voltage drops as high as .3v - .5v at the powercenter with only 5-10a loads---a significant drop.  Under these conditions, this meant our battery could potentially be producing, say, 10.8v (as measured via voltmeter at the battery terminals or the Victron shunt), but our Alde might only be receiving 10.3v.