AC180's DC Input & External Battery

Product Discussion BLUETTI AC Series
1

I want to recharge an AC180 with an external 12V-75Ah deep cycle AGM battery via the Bluetti’s DC Input (rated at 12-60V and drawing up to 500W as per specs).

  • Does the DC input tolerate < 12V (like 11.8V or so) at all or will charging stop as soon as the external Batt < 12V ?
  • is there an internal charge controller that deals with the AGM 12V dc nominal and brings it up to a voltage level capable of charging the Bluettin’s internal LifePo4 batt?

Thx
ldbm

2

@ldbm You can use this battery to charge the AC180.
However, if your AGM battery voltage is too low (below 11.8V), the machine will stop charging and trigger under-voltage protection to prevent your battery from being over-discharged and damaged.

3

ok , thank you for the info.

Further on this, so as long as the external batt is above 11.8V, AC180 will draw current from it. So since the DC In is rated at 500W. I should assume the current draw could reach up to 500W/12V ~ 42A .So would a 40A/4 5A fuse be recommended here (and 10 AWG cable)? Also there is the voltage drop due to the cable length going from Ext batt to AC180 that could impact the bluetti sense read with 11.8V appearing on the DC line relatively quickly, preventing further charging…

…Would instead adding an inverter and recharging via the Bluetti’s AC In be recommended in this case? Less current on the AC line, but added inefficiencies with the DC/AC conversion of the inverter plus AC/DC conversion again inside the Bluetti to charge it. Also, would the AC180 know how much to pull from the AC input or should the inverter’s be capable of delivery ~ 1440W nominally (for the AC180)? Can a smaller inverter be used without risk of damaging it?

thx
L.

4

The AC180’s DC in should be limited to 10A. So it shouldn’t pull 42A.

5

ok , missed the I max. Thx @aaron33