We are testing 2 of the BAT120 units connected to RUT955 on our train. We have exactly the same situation:
Once power is drained, despite the unit plugged into main power for 12hrs, the first two lights of the Power Indicator just flash on and off all the time.
If you disconnect mains power, both the BAT120 and RUT955 lose power.
Having had a response from Teltonika regarding the BAT120 failing to charge, I thought it worth while posting the response here, it has me fuming.
When the BAT120 devices were charging, will they have RUT955 also plugged into them? (yes)
I'm asking this because if the BAT120 was plugged into the PSU together with RUT955, then most likely the BAT120 was not charging and was working as a "passthrough", since in order for BAT120 to charge you will require to unplug the RUT device from it.“
In other words, once the battery runs out of power, you have to remove whatever kit you have plugged into the BAT120, charge it, then plug your kit back in.
The unit seems to be unable to recharge the batteries whilst keeping the connected device running.
Which would totally defeat the point of a battery backup unit.