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wBJr Always Negative Amps

Started by schroew, April 20, 2021, 03:03:14 PM

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schroew

I have been reading this link: http://www.midniteftp.com/support/kb/faq.php?id=113. It seems that my wBjR amps ship;d at some point be positive but I never see it go positive. Without any load it is flatlined at -0.1 A ( 12V system) My 24V system has the same issue at -0.2A). Any idea why? I just checked and the purple wire IS pointing toward the battery cable.

schroew

This is the correct screen I need to be referring to?

boB

Yes, that is the correct screen...

So, it ALWAYS shows a negative current even when charging ?

Is the WB Jr. connected tightly to the shunt ?  i.e.  good connection ?

K7IQ 🌛  He/She/Me

schroew

Always negative and nice and snug. I just checked the tightness. Whats interesting is that both systems are always negative and the 12V system when resting show -0.1 and the 24v system when resting show -0.2 which is double.

boB

Quote from: schroew on April 21, 2021, 03:14:27 PM
Always negative and nice and snug. I just checked the tightness. Whats interesting is that both systems are always negative and the 12V system when resting show -0.1 and the 24v system when resting show -0.2 which is double.

I would have though the 24V would have been half of the 12V current but that's OK...

What if you were to connect up another charger to the battery on the Classic side of the WB Jr. ??  Does the current go positive then ?

How much current does the Classic MNGP screen say it is charging at on its main status screen ?  (Not Wb Jr. screen)

K7IQ 🌛  He/She/Me

schroew

It only goes positive when I apply charge power from the generator.

schroew

the 12v system reads 5A and the 24v reads 5A

boB


In the  picture, the system is in Float so you cannot expect any more current or power out of the Classic in that case.

OK, so here is a question....   

With your generator OFF, do you notice an approximate 5 amp change in the WB. Jr screen current when your Classic PV is turned OFF and ON ?   i.e.  Does the current from your Classic and PV offset the negative 7 amps current shown in your previous picture ?





K7IQ 🌛  He/She/Me

schroew

Sorry, I am not sure what you want me to do??

boB

Quote from: schroew on April 21, 2021, 03:45:15 PM
Sorry, I am not sure what you want me to do??

Check to see if there is a difference in WB Jr. current with your solar on and with the solar off running through the classic

K7IQ 🌛  He/She/Me

schroew

Heading out to the combiner box now-

schroew

With the PV off at the combiner box, the WBJR amps are ~-7.5 and now its -2.7 amps with the PV back on.

boB

Quote from: schroew on April 21, 2021, 04:48:08 PM
With the PV off at the combiner box, the WBJR amps are ~-7.5 and now its -2.7 amps with the PV back on.

Great !   That is what I would expect.

The system was in Float charge mode from your last picture.  When in Float or Absorb, you will not see maximum power from the charger.

If you were to put the Classic into Bulk/Absorb MPPT mode, OR raise the Float voltage, it would  very possibly go positive amps on the WB Jr. screen...
But your batteries are charged so a little bit of negative current is expected when the battery voltage is so close to this Float voltage.

Are you using a battery temperature sensor ?  That would be good.   If the ratings for your batteries allow you to raise your Float voltage ever so slightly, like, 0.1 or 0.2 volts, you may see positive  amperage again.   I believe that may be happening when you charge from a generator...  The battery voltage is being charged at a bit higher voltage through the inverter/charger or whatever you are using for your generator battery charger electronics.
K7IQ 🌛  He/She/Me

schroew

I just took off the cover and physically verified the purple wire is AUX2 +

schroew

I am using a temp sensor! I will try and raise the voltage a little bit and see what happens.