2021 Hawk parasitic drain?

[lost73]

Finally got a Victron Smart shunt installed. Had twin 6V set up and converted to single 12V battery.

When the camper is "off" the battery seems to be drawing a fair amount of current (see photo). When the truck key is set to accessory mode the Victron shows the camper battery drawing even more current. I thought the camper battery was isolated? I checked the fuses to the Blue Seas Systems and they were intact. Any help would be much appreciated!

 

[Jon R]

That Blue Sea ACR, according to its specs anyway, does not disconnect the camper and truck batteries until the voltage sensed at the ACR is 12.75 volts. If you were running the truck, the ACR would have connected, and since the camper battery is fully charged and the truck battery is nearly or fully charged, the voltage sensed at the ACR after truck shutoff initially remains above the ACR disconnection threshold. I suspect most of that parasitic draw is your camper battery charging the truck battery a little bit. Once the voltage at the ACR drops below 12.75 the ACR should disconnect.

 

[Bosque Bill]

I had problems with my battery separator after installing my solar system; it wouldn't turn off (open the contacts). Tried everything, even replaced it with a new one. Finally just put a switch in the sense line so I could disable the contacts from pulling in thus keeping the two batteries separated unless I specifically allowed it. Didn't usually need them connected as the solar keeps the camper batteries well charged. Enable it when traveling on a dark, rainy day, for instance.

I don't have the smart shunt, but just use the load terminal on my Victron to connect my camper. Note: when the camper is drawing current the amperage reading is POSITIVE, not negative as in your images. Either your shunt is connected differently or that shows current flowing from your truck TO your camper batteries. If you are at all unsure, I'd suggest double checking which way the current is actually flowing, perhaps using a DVM or other current meter.

 

[lost73]

I had problems with my battery separator after installing my solar system; it wouldn't turn off (open the contacts). Tried everything, even replaced it with a new one. Finally just put a switch in the sense line so I could disable the contacts from pulling in thus keeping the two batteries separated unless I specifically allowed it. Didn't usually need them connected as the solar keeps the camper batteries well charged. Enable it when traveling on a dark, rainy day, for instance.

I don't have the smart shunt, but just use the load terminal on my Victron to connect my camper. Note: when the camper is drawing current the amperage reading is POSITIVE, not negative as in your images. Either your shunt is connected differently or that shows current flowing from your truck TO your camper batteries. If you are at all unsure, I'd suggest double checking which way the current is actually flowing, perhaps using a DVM or other current meter.

Thank you for the thoughtful reply! For fun tonight I monitored the Victron after letting the truck sit for an hour. I pushed the remote unlock for the truck and the Victron showed negative watts and amps at the camper battery. I was under the impression that the camper battery was "protected" from the truck's battery, or rather the truck could charge the camper battery but not draw from it. I did install the Victron shunt as directed but human error os real. Thanks again for the help!

 

[lost73]

That Blue Sea ACR, according to its specs anyway, does not disconnect the camper and truck batteries until the voltage sensed at the ACR is 12.75 volts. If you were running the truck, the ACR would have connected, and since the camper battery is fully charged and the truck battery is nearly or fully charged, the voltage sensed at the ACR after truck shutoff initially remains above the ACR disconnection threshold. I suspect most of that parasitic draw is your camper battery charging the truck battery a little bit. Once the voltage at the ACR drops below 12.75 the ACR should disconnect.

Thank you kindly! I appreciate it!

 

[Vic Harder]

The "isolator" only isolates when necessary. As JonR pointed out, that "necessary" limit is set at 12.75 volts for that unit. 12.75 makes sense for AGM/FLA batteries, as they are essentially fully charged at around that voltage.

(note: i have not confirmed the voltage... a quick google search - or if you have the manual - would be helpful).

Another thing to check is the "Calibrate" button(not near my camper at the moment... it is in the BMV app --> battery settings, close to the "Synchronize" button. This is used to set the "Zero" current flow.

 

[Vic Harder]

Note: when the camper is drawing current the amperage reading is POSITIVE, not negative as in your images.

I'm not sure you have that the right way around BBill. Mine shows positive when current is going INTO the camper batteries, negative when the camper battery is draining. YMMV??

 

[Jon R]

I have that same ACR so it was easy for me to pull up the specs. Just in case it’s helpful: The literature says it will connect the two sides if either side exceeds 13.0 volts for 2 minutes or 13.6 volts for 30 seconds, and will disconnect when the voltage drops below 12.75. The Blue Sea web site has the specs available.