EQLYTE is a battery ancillary that is inserted at the manufacturing stage with minimal disruption and connected to an electronic controller at battery bank level in-field.
WHAT DOES IT DO?
EQLYTE uses the airlift principle in a NOVEL way to actively deposit electrolyte in different regions of the battery in response to charge, discharge and float respectively.
WHAT BATTERY TYPES?
EQLYTE can be integrated into any flooded battery. This includes all motive, stationary and transport applications and further includes EFBs and Bi-Polar cells.
CAN BE INTEGRATED INTO ANY FLOODED CELL
Enhancing flooded batteries such as SLI, EFBs and Bi-Polar designs to provide extended life and DCA capabilities for automotive Stop/Start.
Integrated into Motive and Traction cells to allow rapid recharge time, extended cycle life and extended operational runtime in-field.
Optimizing stationary value proposition through increased discharge capacity and cycle life with multiple cycles per day.
FIRST A WORD ON STRATIFICATION
Many of the limitations of current Pb-Acid batteries are in-part caused by electrolyte dynamics and stratification and these include such issues as:
BMS determines incorrect battery status
In-homogeneous current distribution
Capacity loss (Premature end of life)
Negative plate sulphation (Bottom part of plates)
Larger PbSO4 crystal growth (More expansion)
Premature aging and end of life
Reduced cycle life in PSoC
Lower DCA performance
Higher Internal resistance
Deeper DOD cycles increase acid stratification
BUT WHAT if stratification could be leveraged?
THE SOLUBILITY DILEMMA
The figure presented by Pavlov seen here demonstrates how electrolyte specific gravity influences the solubility of PbSO4. This is one of the most profound figures on the electrochemical hydrodynamics within the Pb-Acid battery.
The figure can also be considered as a reflection of electrolyte density during charge and discharge, where during discharge, SG will be lowered, moving more towards the left of the plot, whilst during charge, electrolyte SG is increased, moving towards the right of the plot.
This means that when we discharge, we reduce SG and thereby availability of SO4 in the solution, which is bad for discharge and when we charge we increase SG and lower PbSO4 solubility which is bad for charge.
This CONUNDRUM is a hard limit in ALL flooded batteries today, but can be addressed with the use of EQLYTE to provide what we need, when we need it.
"We want high sg during discharge and low sg during charge"
HIGHER DISCHARGE VOLTAGE
A 2-Volt flooded Motive power cell (3PSZ-165Ah) demonstrated that the EQLYTE improves average discharge voltage at a given constant current load by providing a more uniform distribution of electrolyte at a higher average density across throughout the active battery block, thereby allowing the given motive power cell to provide more discharge ENERGY.
HIGHER DISCHARGE CAPACITY
A 2-Volt flooded Motive power cell (3PSZ-165Ah) demonstrated that the EQLYTE improves average discharge capacity by allowing for the uniform utilization of active mass accross the entire battery plate geometry, thereby eliminating the over-utilization and under-utilization disparity between the top and bottom regions of the battery.
This provides for an increase of between 25% – 30% more Ampere-hour capacity
HIGHEST ENERGY DENSITY
An increase in usable capacity coupled with an increase in average discharge voltage allows for a battery that incorporates the EQLYTE ancillary to deliver the HIGHEST Wh/Kg energy density as compared to best-in-class alternatives. This figure also demonstrates how the EQLYTE provides scalability with larger individual cell capacities, improving industrial motive power energy density to above 45 Wh/Kg, just shy of the Consortium for Battery Innovation (CBI) target of 50Wh/kg on automotive batteries. [Watt-hour per Kilogram given at C/5 discharge rate to 1.7Vpc at 30DegC)
RAPID & EFFICIENT RECHARGE
Tests conducted by the South African Bureau of Standards (SABS) on a 2-Volt motive power cell (3PZS 165Ah C/5) demonstrated an improved cell performance:
Cycle Settings: 45A constant current discharge for 3.5-hours with an 80A constant current charge for 3-hours immediately after the discharge to model unstable grid.
The results show a a consecutive charge/discharge cycle test for 25 cycles with little over 100% of discharged Ampere-hour recovered during recharge which allowed for the maintenance of the 25 cycles at this high rate of discharge and recharge.
This effectively allowed for the cell to be discharged and recharged 4x during a 24-hour period at a coulombic efficiency of ~98% over the 25 cycles.