Overview

Coleman CPX6 Compatible

I received a lantern with a dead battery. Decided I would try to rebuild the battery using some 18650 lithium ion batteries I had kicking around.

Teardown

These lanterns use a lead acid battery (6V 2.6Ah)

Upgrade

Battery

I replaced the lead acid battery with 4 18650 Lion batteries in a 2S2P configuration for about 5Ah at 7.2v nominal (36 watt-hours).

Two batteries on each side of the compartment seemed to work.

BMS Board

2S 2-3A 5-8.4V Red
Size: 62 x 26 x 6.9mm
Charging Voltage range: 8.40-8.45V ± 0.05V
Over-discharge Voltage range: 4.6-5.1V ± 0.05V
Maximum operating current: 2-3A
Maximum instantaneous current: 4-6A
Working temperature: -40 ~ +50°C
Resistance: less than 45mΩ

Wired the leds on the BMS to the original circuit board led. Removed all components from the original board except the power plug and battery led.

Final Picture