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danielbeck500 asked

MPPT stuck in Bulk even past float voltage

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e4b937b2-2772-41df-9bde-309df8a63eb1.jpegImage Caption Hello, I have been running self consumption hub on my setup until experimenting with ess. After reverting back to self consumtion hub my 150|100 charge controller stopped following the values for bulk float and absorption. This leads to voltages of over 33V shutting my 24V victrons down. You can see how I set 32.57V as my bulk voltage the system reaches 32.61V and is clearly still in bulk. It dose eventually go to float and absorption, but but at inaccurate voltages and often exeeds my systems max voltage.

MPPT Controllers
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3 Answers
JohnC avatar image
JohnC answered ·

@Danielbeck500

If that Temp Comp figure is in play the setpoints get changed. That won't show in the settings, but the real V it's targeting will alter.

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danielbeck500 avatar image danielbeck500 commented ·
Bingo fixed!! For now I’m going to be running without this feature, until I do some research for the correct value to use for my temperature compensation. In any case I’m running my batteries safe as the main limiting factor is the maximum system voltage of 33V, that corresponds to a individual cell voltage of 4.1V so still far from the max charged voltage for these prismatic cells, but still enough to enter the balancing phase.

Thanks a lot, as I always overlooked this setting when trying to fix this problem.
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kevgermany avatar image
kevgermany answered ·

Before trying to answer, please give us more information. You have 24V batteries?

System is configured for 36V, but voltages are set too low for that?

Running 24V batteries at 36V will kill them very quickly and will lead to poisonous gas being emitted.

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danielbeck500 avatar image danielbeck500 commented ·
Sorry for not mentioning it before in my original post.

I’m running a 8S prismatic cell configuration.

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klim8skeptic avatar image
klim8skeptic answered ·

You have set you battery voltage in the mppt as as 36v?

And a bulk / absorption as 32.57v?

Yet your float voltage is higher at 32.73v?

And you have 24v system components?

You need to check your battery and system parameters again.

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danielbeck500 avatar image danielbeck500 commented ·

Those are test values for the purpose of this problem of overcharging that I’m having. Normally I run closer to 33V, as it is a 8S lithium Ion cell configuration.

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