Ericson 27 1976 "Lotus Flower"
After 8 years of use with AGM batteries for propulsion I have removed and replaced them with lithium (LiFePO4). The AGM's were still working fine for short term motoring needs but the range capacity had definitely dropped in the past few years.
Lotus Flower had two 48 volt AGM battery banks. One bank of group 27's and one bank of group 31's. The lead acid batteries worked well and were relitivaly simple to install.
The new lithium battery setup also has two 48 volt banks. The batteries are Sky Energy (now CALB). Bank one, under the starboard settee is made up of sixteen 160ah prismatic cells and bank two, under the port settee is sixteen 40ah prismatic cells. Each bank has its own charger and Battery Management System (BMS).
While making this switch I was able to remove over 400lbs from the boat. Part of the weight loss was due to added ballast on the starboard side of the boat after the interior remodel, Corian weighs a lot! By installing the heavy 160ah bank on the starboard side and the much lighter 40ah on the port side the boat balanced beautifully without the added 170lbs of ballast.
With any lithium install there is the need for a BMS. The system I installed on Lotus Flower is the Mini BMS made by CleanPowerAuto. The BMS will turn the charger off if any of the 16 cells reaches a charge level of 3.6 volts and during use will sound an alarm if any of the cells drops below 2.5 volts. The BMS adds some complexity and a lot of wires compared to a lead acid install but that is pretty much the only down side to lithium vs LA.
Some of the pluses for lithium over LE are light weight, energy density, voltage consistency, more usable capacity and quicker charging. Another advantage is that lithium batteries are not damaged by sitting at less than full charge. As I understand it lithium can sit for long periods at 50% charge and not be damaged. The quicker charging characteristic of lithium is intriguing as it should allow more effective charging during regeneration while sailing.
This is the 160ah bank on the starboard side. The wires include series connection for the 48 volt nominal system, BMS, charging and PakTrakr monitoring.
The port side 40ah bank.
The new starboard settee battery cover.
Lotus Flower had two 48 volt AGM battery banks. One bank of group 27's and one bank of group 31's. The lead acid batteries worked well and were relitivaly simple to install.
The new lithium battery setup also has two 48 volt banks. The batteries are Sky Energy (now CALB). Bank one, under the starboard settee is made up of sixteen 160ah prismatic cells and bank two, under the port settee is sixteen 40ah prismatic cells. Each bank has its own charger and Battery Management System (BMS).
While making this switch I was able to remove over 400lbs from the boat. Part of the weight loss was due to added ballast on the starboard side of the boat after the interior remodel, Corian weighs a lot! By installing the heavy 160ah bank on the starboard side and the much lighter 40ah on the port side the boat balanced beautifully without the added 170lbs of ballast.
With any lithium install there is the need for a BMS. The system I installed on Lotus Flower is the Mini BMS made by CleanPowerAuto. The BMS will turn the charger off if any of the 16 cells reaches a charge level of 3.6 volts and during use will sound an alarm if any of the cells drops below 2.5 volts. The BMS adds some complexity and a lot of wires compared to a lead acid install but that is pretty much the only down side to lithium vs LA.
Some of the pluses for lithium over LE are light weight, energy density, voltage consistency, more usable capacity and quicker charging. Another advantage is that lithium batteries are not damaged by sitting at less than full charge. As I understand it lithium can sit for long periods at 50% charge and not be damaged. The quicker charging characteristic of lithium is intriguing as it should allow more effective charging during regeneration while sailing.
This is the 160ah bank on the starboard side. The wires include series connection for the 48 volt nominal system, BMS, charging and PakTrakr monitoring.
The port side 40ah bank.
The new starboard settee battery cover.
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