question

lukeoslavia avatar image
lukeoslavia asked

LifePo4 - Skipping Bulk Phase going to Absorption

Recently I accidentally ran my 2x 110AH LifePo4 batteries below the 13V mark, when trying to charge using either my 100/30 MPPT or 12/12 30A DC/DC charger the charging phase goes straight into absorption mode and skips bulk phase, the output voltage is 14.2V with 0A current.


As this is my first time running the batteries this low, I don’t know if this is normal or not? Out of fear of killing my batteries I have disabled both chargers, so my voltage is currently sat at 12.63V.


Both MPPT & DC charger are using Smart a lithium profiles, so not sure what is going on here..


Any help would be massively helpful, my suppliers that I purchased the Victron equipment, don’t seem to have a clue!


Many thanks!

MPPT ControllersMPPT SmartSolarorion-tr smartvictron productsvictron community
1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

snoobler avatar image snoobler commented ·
13V is a non-issue. With LFP, 10.0V min is attainable provided all 4 cells hit 2.5V at once, which usually isn't the case. In any case, at 12V or 3.0V/cell, you still have 5-10% capacity remaining. At 13V, about 30%.


Have you successfully charged these before?


Smart Lithium? Are these Victron batteries?



0 Likes 0 ·
3 Answers
wkirby avatar image
wkirby answered ·

It seem that the battery is not connected to the system. If the chargers don't have a battery in the circuit to charge then they will reach their target Voltages very easily and go straight to absorb stage just like they should.

The first few reasons that I can think that the system is not connected to the battery may be an open fuse or circuit breaker.
Some Lithium batteries have their own BMS inside and maybe it has disconnected in order to prevent the battery form being discharged any further during the previous discharge event.
The battery manual should describe how to proceed after the internal BMS has activated.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

chuckenglehart avatar image
chuckenglehart answered ·

I was seeing the same behavior with a small LiFePO4 battery on a Victron IP65 charger. Li-Ion charge cycle. Bulk went almost immediately into ABS and no current went into the battery. The battery manufacturer determined that it was a battery fault and replaced it under warranty. Some research makes me think that the BMS has tripped or failed.


See if you can get in touch with the battery manufacturer and see if there is a way to reset the BMS. If you have successfully used these chargers in the past, I would suspect a battery issue. Do you have any other chargers that you could test on the battery?

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

djsmiley avatar image
djsmiley answered ·

Which batteries, and what is the temperature of them? You would have the same results if a BMS has cut-off the charging due to undertemperature. (usually 0-5C depending on the BMS settings)


2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.