EXTIO4 type 2 reconnect after low voltage disconnect

[Chris Card]

Forgive the beginner question but I’m rusty on how EXTIO4 set to type 2 will behave after the battery voltage recovers back up to above the “low voltage recovery” set in advanced parameters.  Will the NC connection resume on EXTIO4 automatically, or is manual intervention always required (hold Ok and choose “load on”)?

I don’t tend to let my battery discharge to that level so unsure what will happen. Perhaps my dim recollection from years ago of having to use the manual way to reconnect loads was an occasion when I needed to get things working again before the battery voltage had risen to the recovery level?

[Dacian Todea (electrodacus)]

By default the EXT IO3 is used to control ON/OFF the loads and thus set as type 2 the EXT IO4 by default is set as type 1

If the battery voltage drops below (2.8V default LiFePO4 setting (any cell) ) then EXT IO3 set as type 2 will become open circuit and as soon as all cell voltages exceed (3.2V default recovery) the EXT IO3 set as type 2 will be close circuit so enable the Loads.

So all should be done automatically assuming there are no other errors and you just get a battery discharged over night.

Issue can happen if the SBMS is not able to switch off all loads due to either incorrect connection or some defect then if voltage drops below (2.5V under voltage lock) then both Type 1 and Type2 are off so there will be no charging and require manual intervention as that is something should not happen in normal conditions.

In that case you will need to asses the battery if lowest cell is not much below 2.5V say maybe 2.1V and it was not long at that level maybe a day or two then you can force enable charging by just manually shorting the EXT IO4 wires to enable charging and watch the charging process at all time as it should not take more than a few minutes to get above 3.2V and then you can remove the short on EXT IO4 (set as type 1) and let the process continue automatically from there.

Make sure not to confuse type 1 and type 2 and also when you make the settings (maybe you already did that) go to Device settings and push "Store device settings" as that will store your selection say EXT IO3 as type 2 and EXT IO4 as type 1 so even if you power cycle the SBMS the settings will remain as you prefer. If you do not save the settings they will be at default after a power cycle and default is EXT IO3 as type 2 and EXT IO4 as type 1 (maybe I should have the default all at type 0 but then it may confuse many people of why their newly installed SBMS is not working).