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Rob Duthie avatar image
Rob Duthie asked

Lithium restart bulk to float Mulitiplus2

Hi


Re the restart of the bulk mode from float, so the restart voltage for 48v systems are

Lithium: restart-bulk-voltage = Vfloat - 0.8V to 3v (max 54V) range is this correct?

For my system settings are set to 57v for Absorb and float 57v as well, so when it falls below the 57v level down by 0.8 to 56.2v it should reset to bulk mode, or the max setting which is 54v. when mine falls below 56.2v it does not go into bulk charge mode it stays in float mode and charges in float only. Unless i do system reset or use more energy from my battery pack until i falls below the 54v level. What determines this value?

Is there away to change this setting in vebus config file?


Please advise

Regards

Rob D

NZ

Lithium Battery
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2 Answers
Paul B avatar image
Paul B answered ·

What do you mean by max setting 54V as this is below your 57V charge settings

absorption set at 57 this is the same as Bulk anyway

it will charge max current until it reaches the absorption trigger 57v then hold this voltage for the absorption period and then change to float both settings should normally not be the same


anyway your max voltage setting of 54 has me confused

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Rob Duthie avatar image Rob Duthie commented ·

This is a setting in one of the blogs about the lithium battery setting it is the max minimum setting, When using other lithium battery systems these setting can be the same or slightly different by what ever amount from 0.2 to 0.8 of a volt. Might the Dutch to English translation?

This was noted by M Vader himself in a thread.


So to reset the the float from float to bulk the voltage has to drop by a certain amount

eg 57-0.8 = 56.2 or 57-3 = 54volts range that it works in? this is what i am trying to find out what is correct range and settings how it resets to the bulk mode.

An these is away of changing this in the DBus code etc.

I have tested this and to reset the float to bulk the voltage had to drop below 3v from float to trigger the bulk mode, so from a float setting of 57v to 54v is the range to reset.

So is there away of changing this to a lower setting somehow instead of a 3v span it can be set from 1.5 to 3v span change before a trigger to bulk?

Please advise


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boekel avatar image
boekel answered ·

If you set bulk and float to the same voltage, the system doesn't have to go back to bulk, it will always try to maintain the same voltage.

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Rob Duthie avatar image Rob Duthie commented ·

Yes i have set the Absorption and float to 57v each in VE configure 3.

After i tested the volt drop required to trigger a reset to bulk.

Otherwise if it never gets to the trigger point it just stay in float mode charging

So to reset the the float from float to bulk the voltage has to drop by a certain amount

eg 57-0.8 = 56.2 or 57-3 = 54volts range that it works in? this is what i am trying to find out what is correct range and settings how it resets to the bulk mode.

Is their away of changing this in the D Bus code settings etc.

I have tested this and to reset the float to bulk the voltage had to drop below 3v from float to trigger the bulk mode, so from a float setting of 57v to 54v is the range to reset.

So is there away of changing this to a lower setting somehow instead of a 3v span it can be set from 1.5 to 3v span change before a trigger to bulk?

There might be some code change in the VE Configure 3 in the ESS Assistants which might need changes to allow for this for other Lithium batteries mode. something to think about.

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boekel avatar image boekel ♦ Rob Duthie commented ·

I'm sorry I don't have an answer for this, as I only have systems with CANbus BMS batteries.

To summarize:
Your observation is the re-bulk mode is only starting with a 3v drop, instead of the 0,8v expected with lithium-battery selected?

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Rob Duthie avatar image Rob Duthie boekel ♦ commented ·

Yes that is the observation so far, but the range is anywere between these values, so far on what i have read on this forum.

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