Why am I getting a voltage drop?
Last month I bought and installed 4 x 700Ahr cells from Balqan (with their BMS) to replace a Lead Acid house bank with a 700Ahr 9Kwh LifePO4 battery
. I essentially just swapped out the 2 stock batteries and left the rest of the configuration of starting and bow thruster-auxiliary Lead Acids unchanged. At the same time, I upgraded to a 160 amp alternator
. This represented an enormous undertaking for me, because I really am a full novice
systems. I was rather proud to install it all myself and connect it in our 2011 Beneteau
We left a few days later for a family vacation
and have been at anchor
now for 27 straight days.
Something isn't quite right yet and I need advice to fix it.
After motoring for about 20 straight hours and approaching our anchorage, I got a low voltage alarm
. Bow Thruster battery showed 15 volts (at the dock
, one relay I believe connects to bow thruster was making a clicking noise
- thruster wouldn't turn on- fuses intact) I have switched off the leads to that battery in case it is burning out and somehow siphoning off voltage).
The Li appears to charge. My Victron monitor
reports we maintain a typical state of charge between 65-80%. The big problem is that the voltage drops quickly. While charging
I see approx 13.5 v. Then I need to recharge within about 18 hours because the voltage drops to under 12v. This can follow a session of running the motor
anywhere from 2 hrs to 7 hrs.
is drawing only about 4-8 amps at any given time.
I have my regulator
set to "Gel" and for:
Bulk 13.99 (shortest time possible)
Absorption 13.7 (2 hrs)
Float 13.12 (shortest time possible)
Field threshold (float to absorption) at 25
Field threshold (bulk to absorption) at 90.
Adjusted the Belt Load (or "Amp") Manager to approx 80%.
*Time frames are following Balmar's suggestions to accommodate lithium batteries.
Is my problem:
- In the regulator programming?
- Lead Acid in the system (maybe a bad cell)
- Isolators somehow interfering?
- Bad or low balanced Li cell (The cells were shipped with approx 65% charge and balanced.)
I've read through hours of postings. My family
isn't happy because the system isn't performing as promised. Any assistance will be much appreciated.
I need to solve for the voltage drop and the loss of bow thruster.
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