Whizbang Jr: useful despite a separate DC load running off battery bank?

[kateonmars]

Hi there,
I have an off-grid solar set-up in the subarctic that includes two Kid controllers (in master-slave configuration), four Rolls AGM 6v batteries set up for 12 V (830Ah bank), and four 315W solar panels. All my AC loads (laptop, some LED lights, internet routers) run through a MMS-1012 1000W Pure Sine Wave Inverter, except for a chest fridge/freezer, which runs on DC directly off the battery bank with alligator clips. I'd like to install a Whizbang Jr to better gauge absorb time for my battery bank, but I don't know enough about how this device works to know whether that separate DC load running off the battery bank will render it useless. Can anyone clarify this for me?

Thanks so much in advance!

[Highflyer]

Here is the link to the Whizbang Jr as used by the kid. To install it correctly the WBjr's is installed so the tail in on the battery side of the shunt.  ALL inputs and outputs attach to the shunt on the other terminal.  That way the Kid can "see" the energy flow into and out of the battery.

https://www.midnitesolar.com/productPhoto.php?product_ID=519&productCat_ID=43&sortOrder=9&act=p


Hope this helps.

[ClassicCrazy]

The Whizbang is worth it  - once set up you will have a very good idea of how many amps you take out of the batteries, and how many you put back in. You can see how much power is going to loads vs how much goes to charging the battery. It will also give you a good idea of the State of Charge SOC which is reflected as percentage of remaining battery capacity.
For lead acid batteries, if you want them to last a long time you want to not cycle them too deep. If you look up on your battery manufacturer they usually show how many cycles you can do at a certain depth of discharge. You will find that only taking 20% out of them give the batteries a much longer lifespan than if you take 50% or more.
Having the Whizbang on your system won't use any extra power.

Larry