Assumptions

18650 Battery Assumptions

Specification	Value
Nominal Voltage	3.7v
Max Voltage	4.2v
Cutoff Voltage	3.0v
Capacity	2500mAh

Configuration Options

This section will look at the pros and cons of a 3S versus 4S configuration.

3S (9V-12.6V)

Specification	Value
Nominal Voltage (3 x 3.7v)	11.1v
Max Voltage (3 x 4.2v)	12.6
Min Voltage (3 x 3.0v)	9v
Cells in Series for Voltage	3

Pros:

Can charge it from the car
Works with most chargers (solar and car chargers)

Cons:

Would not get full capacity when using with an inverter. The inverter would shut off at 10.5v.

4S (12V-16.8V)

Specification	Value
Nominal Voltage (4 x 3.7v)	14.8v
Max Voltage (4 x 4.2v)	16.8v
Min Voltage (4 x 3.0v)	12.0v
Cells in Series for Voltage	4

Pros:

Would be able to use the full capacity of the battery when converting to AC.

Cons:

Would need to step down the voltage to 12v which may introduce some losses.
Could not charge it off of the car

Configuration

Battery Spec 3S56P - (130 Ah)

Specification	Value
Nominal Voltage (3 x 3.7v)	11.1v
Max Voltage (3 x 4.2v)	12.6
Min Voltage (3 x 3.0v)	9v
Cells in Series for Voltage	3
Parallel Cells to Get Capacity 80Ah/2.0Ah	56
Total Cells Required	168

Specification	Details
Capacity	112-128.8 Ah
Cell Capacity	2.0-2.3 Ah
Cells	3x56=168 cells

The Plano 50 Cal Ammo Box can hold a total of 192 cells (about 150Ah).

Battery Management System

50A BMS

3Series 50A 11.1V/12V/12.6V BMS PCB Protection Board for 18650 Li-ion Battery Cell with Balance

Features

Continuous Discharge Current: 50A
Momentary Discharge Current: 150A
Charge Voltage: 12.6V
Charge Current: 50A
Overcharge Detection Voltage: 4.28±0.025V
Overcharge Protection Delay: 0.5S
Overcharge Cancel Voltage: 4.08±0.1V
Balance Detection Voltage: 4.20±0.025V
Balance Cancel Voltage: 4.20±0.05V
Balance Current: 60±5mA
Over-discharge Detection Voltage: 2.8±0.1V
Over-discharge Detection Delay: 0.1S
Over-discharge Cancel Voltage: 3.0±0.1V
Overcurrent Detection Voltage: 150mV
Overcurrent Detection Delay: 9mS
Overcurrent Protection Current: 200±10A
Protection Cancel Condition: Disconnect Load
Short Circuit Protection Condition: Outside Load Short Circuit
Short Circuit Detection Delay: 250uS
Protection Cancel Condition: Disconnect Load
Main Circuit Conduction Internal Resistance: ≤25mΩ
Working Current: ≤30uA
Sleeping Current(Battery Over-discharge): ≤10uA
Operating Temperature:﹣30℃~﹢80℃
Size: 75×51.5×15mm/2.95×2.02×0.59"

100A BMS

3Series 50A 11.1V/12V/12.6V BMS PCB Protection Board for 18650 Li-ion Battery Cell with Balance

Battery Hookup Modem Batteries

COMES OUT TO ONLY $70/KWH!

Only 56 cents per cell! For $4.50 you get a modem battery with 8 LG 2200mah LGDAS31865 cells! Get them while they last! Last time we listed these a company bought almost all of them.

We spot tested tens of thousands of these cells and they came out around full capacity overall. These are a great source of genuine LG 2200mah cells because the modem batteries are either never used at all or they were used as backup only with less than 3 cycles. Modem batteries only gets cycled hen a house loses power which is very rare in our region.

Brand:	LG
Model:	LGDAS31865 (ICR18650S3)
Capacity:	2200mAh Rated
Voltage:	3.60V Nominal
Charging:	4.20V Maximum 1075mA Standard 2150mA Maximum
Discharging:	3.00V Cutoff 430mA Standard 3225mA Maximum
Description:	Blue Cell Wrapper White Insulator Ring 18650 Form Factor

Almost every pack we opened had the light blue lg cells, some had dark blue lg cells with the same specs. Either way they are all name brand cells, the best ones out there