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jdm avatar image
jdm asked

250/85 going to float 150/70 x 2 still in absorb

I just expanded an existing installation by adding a 250/85 to an existing system with 2 x 150/70 charge controllers . All wired up this afternoon, but the new charge controller is just sitting in float rather than charging as well. The old chargers are in absorb and the new addition goes straight to float, meaning the new array is not doing anything . Is there a fix for this ? One thought I had is the the 150/70s are using the adaptive charging ( which I cant change) and the new one I have set to fixed absorb time . The 250/85 didn't even run through its full absorb time before going to float

thanks in advance

battery chargingcharge controller compatibilityfloat
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Alexandra avatar image Alexandra ♦ commented ·

@JDM I would start by checking the settings on the new one is the same as the other two and that their firmware is uptodate. My other thought is that if there is nothing co ordinating or externally controlling them like a GX device, is that the cable length to the battery is different so it is detecting differently?

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jdm avatar image jdm Alexandra ♦ commented ·

Hi Alexandra,

Thanks for the quick reply.there is no GX device and the cable length is different , but both have a voltage sense and so should be reading the same battery voltage. The firmware for the 250/85 was updated today. I hope its setting issue - I will check after the sun rises tomorrow. The 2 x 150/70s are connected via Can.

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3 Answers
Daniël Boekel (Victron Energy Staff) avatar image
Daniël Boekel (Victron Energy Staff) answered ·

Hi @JDM

When one controller is in absorption mode (and maintaining absorption voltage), the rest doesn't have to stay in absorption as they are not needed to maintain that voltage.

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jdm avatar image
jdm answered ·

Hi thanks Daniël,

just seems strange that the new array wasn't contributing at all. The voltage was on target but even so I would have thought there would have been some current input from the new charge controller.

so at least in the bulk stage with rising voltage and constant current, they should all be working together?

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ commented ·

Yes if in Bulk they are not all contributing, something is wrong (settings, wiring, panels, mppt, etc)

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jdm avatar image jdm Daniël Boekel (Victron Energy Staff) ♦♦ commented ·

Hi Daniël Boekel ,

OK thanks I will
look into it . If the controllers start at different times , as in our case we have different string voltages, could that cause issues? They were all in absorb or float this morning, although only one was producing current ( which differed significantly from the bluesolar LCD to the measurement of my clamp meter).

250/85 bulk in for 3 hours, absorb for 50mins and then float. As I had set the absorb time to a fixed ( 4.5hours) period surely it should have been more than this ?


I've since changed the settings so now they are the same across all chargers , I also disabled tail current to see If i can prolong the absorb stage.


Thanks again and in advance

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mjs500 avatar image
mjs500 answered ·

blue or smart solar mttp ?

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