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lehrling avatar image

SmartSolar MPPT 100/30 Absorption Settings Behaviour

Can anyone please clarify what the expected absorption behaviour is when set this way?

Will this result in getting 4 hours of absorption time unless current drops to 3 amps with voltage at set absorption voltage?

I have read through many posts, many are getting old and changes in firmware may have occurred.


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absorption
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2 Answers
JohnC avatar image
JohnC answered ·

Hi @Lehrling

The Tail will take effect, and override either the Fixed or Adaptive settings. You can turn it off by setting to zero Amps.

I haven't gone back over the firmware changelogs, but the manual may also have changed from the exerpts you've quoted. I found this, which seems to explain it: (edit: revised link): https://www.victronenergy.com/upload/documents/MPPT_Solar_Charge_Controllers/VictronConnect_-_MPPT_Solar_Charge_Controllers-en.pdf See Section 4.1

I use Adaptive and Tail, and the Tail wins every time. My Tail passed on from a Smartshunt, and gives a great result when the mppt is covering loads as well as charging.


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"The Tail will take effect, and override either the Fixed or Adaptive settings. You can turn it off by setting to zero Amps."

Is there room in the manual for this simple and excellent explanation?

The link you provided does not work unfortunately.

Thank you.oops.png

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JohnC avatar image JohnC ♦ lehrling ·

Link fixed. Seems clear enough, but doesn't mention Tail under Adaptive. But there may be alternative circumstances where my observations mightn't apply (but I can't think of any).

And no matter what the manual sez, I always test this type of thing myself when making such changes.

lehrling avatar image lehrling JohnC ♦ ·

Thank you, the link to the VictronConnect manual is exactly what I needed, it does explain it perfectly.

From VictronConnect manual:

When the charge current decreases below the Tail current and/or the pre-set Absorption time has elapsed, the battery is fully charged. The Controller switches to the Float stage.

Tail current

Set the current threshold that will be used to finish absorption phase before the maximum absorption time expires. When the battery current gets below the tail current for one minute, the absorption phase will end. This setting can be disabled by setting it to zero.

lehrling avatar image
lehrling answered ·

The manual really does not explain how fixed absorption works with tail current - can tail current setting cut the fixed absorption time short?

From manual:

It is possible to override the default absorption time algorithm

by setting a fixed absorption time when programming the solar

charge controller. Be aware this can result in overcharging your

batteries. Please see your battery manufacturer for

recommended settings.

4. Absorption time determined by tail current

In some applications it may be preferable to terminate

absorption time based on tail current only. This can be

achieved by increasing the default absorption time multiplier.


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