question

Mike Baehre avatar image
Mike Baehre asked

Power draw during float

Shouldn’t the MPPT be able to see a load (for example 6A refrigerator) and adjust the amps going to the battery during Float?


I routinely see my system in float (13.3V, 2A) on a nice sunny day when our boat fridge comes on (6A) and the battery monitor shows about -4A. Shouldn’t the MPPT be able to see this load and adjust the Amps it is putting out?


Configuration on my boat:

All components Bluetooth enabled and communicating with each other when I check their settings.

310W panel going to 100/30 Smartsolar MPPT

2 x 140W panels going 100/30 Smartsolar MPPT

BMV-712 monitor

Smart battery sense

12v boat system

500AHr house bank (4 x 125 AHr Lifeline AGMs)


MPPT Controllers
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1 Answer
klim8skeptic avatar image
klim8skeptic answered ·

500AHr house bank (4 x 125 AHr Lifeline AGMs)

13.2v is to low to set the mppt float voltage.

1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

kevgermany avatar image kevgermany ♦♦ commented ·
@Mike Baehre

MPPTs use battery voltage to decide when to switch out of float. Apart from your low float setting, your large house bank won't show a significant voltage drop under this low load. They will continue to charge from the float current.

If you wish, the voltage drop required can be adjusted, default is 0.4V, reducing this will restart the charge cycle once the voltage drop is reached. Making this setting too sensitive will reduce battery life, so don't overdo it.

0 Likes 0 ·