How To Repair Ryobi Lithium Battery

Introduction

This guide applies to Ryobi Ane+18V Li-ion Battery (130501002), merely should also have more general application. This guide will show yous how to disassemble the battery pack and check the cell residuum and rebalance the cells if necessary.

The bombardment should normally measure about 18V across the terminals (21V max). If it reads about 12V, and then information technology is probable the bombardment protection circuit has activated considering of cell imbalance. (Those were my symptoms.)

Cell re-balance could besides help if the battery isn't taking a full charge (not showing green on the fuel guage button).

The fourth dimension estimate for this guide is for disassembly and cell balance measurement. Jail cell rebalance charge time is actress.

CAUTION: Battery disassembly exposes high current circuits. Be careful!

This battery is of 2P5S configuration (sets of two parallel cells, 5 sets in a serial string). Information technology uses Sanyo 18650 Li-ion cells.

CAUTION: Battery disassembly exposes high current circuits. Be careful!

CAUTION: Bombardment disassembly exposes high electric current circuits. Be careful!
Remove the four T15 security screws from the bottom.
Remove the one T10 screw on the top.

Lever the cover clips to remove the top cover. Leaver up so the base pops out.

Lever the cover clips to remove the top cover. Leaver up so the base pops out.
Using an insulated musical instrument, lever the bombardment terminal assembly down inside the top cover.
Caution: use of a metal instrument for the in a higher place footstep risks shorting the battery contacts.

Once there is enough gap, reach in and hold the bombardment terminal associates, while sliding off the acme encompass.
The battery catch clips on the sides tin can be removed if you want.

With a Digital Multimeter (Volt Meter) set to DC Volts, measure the cell balance. The nickle straps are good exam points. Notation the cell voltages.
Cell 1: TP6 to CL1
Cell two: CL1 to CL2
Cell 3: CL2 to CL3
Cell 4: CL3 to CL4
Cell 5: CL4 to CL5 (Battery Pos)
The prison cell voltages should be in the range three.0V to iv.2V. The cells should all read nigh the same, say 3.9V. If the cells are more than 0.1V different, then prison cell imbalance could be a problem for your battery pack.

Utilize a Benchtop Power supply with adaptable voltage and adjustable current limit. Voltage and current meters are necessary too. Instance, the Topward 3000 series. Gear up the voltage to the higher jail cell voltage you measured, only no more than four.2V. Set the electric current limit to 0.5A.
Connect the power supply to the cell to be charged upward (rebalanced), positive to positive, negative to negative. Crocodile clips are useful for this.
Every bit the cell charges upwards the voltage will rise and stop at the fix voltage, then the current volition offset to decrease toward zero. When the electric current drops to virtually zero the cell is charged.
Remove the power supply and repeat the cell voltage measurements.
Repeat charging on other cells until all cells are within most 0.1V.