i have seen so many articles, auction listings etc, regarding these units being faulty

faults including :

light flashing / on constant when trigger pressed / cuts out after few seconds etc.

so i thought what was all the fuss about so i bought a faulty one complete with battery/ charger. with the fault cuts out after 3 seconds.

so i decided to investigate further and discovered he following.

the battery seemed to be unable to hold a decent charge, though should seem no reason to not run the the following motor for more than 3 seconds, after digging deeper inside i learned of the following.

the motor is a standard brush type, possible 22v dc type as the battery voltage is 22v.

the electronics by design deal with the following:

battery charging, though not the best design, the 6 qty 18650 cells are charged connected together in series with only two wires for charging the battery pack, though another pair are for the thermistor (monitoring battery heat) when charging or while running the motor.

the original design was to only run for 6 minutes from a complete charge !!

have discovered by substituting the battery voltage supply with a variable voltage power supply the following:

1. voltage lower than 16v motor will not start

2. voltage of 16v and above up to 22v the motor will start

the motor will stop or not run in the following conditions:

1. main filter with built in magnet has to be present to satisfy the hall effect switch.

2. battery voltage lower than 16v motor will not run

3. motor will stop when battery voltage reaches <16v

4. thermistor has detected over heat in battery pack.

5. abnormal suction causes more motor current draw, circuit will shut motor off

next pages will show you more about what goes on inside the dc 16

Step 1: This Is a Photo of the Pcb in the Main Body Near the Fluff Bin Release Switch

this is a photo of the pcb in the main body near the fluff bin release switch

Step 2: This Is the Pcb Mounted on the Motor

this is the pcb mounted on the motor, access to this pcb and the motor is a little tricky, as it requires the red and black wires being desoldered from the main body battery connector along with the grey ribbon connector being unpluged from the main body pcb, the thin plastic piece on the bottom of the handle being removed after removing all covers. then offer the wires up to the the motor as you pull the motor out.

Step 3: This Diagram Shows How It Is Wired Internally and How to Bypass the Electronics

this diagram shows how it is wired internally and how to bypass the electronics, notice the battery pack wires head straight to the motor pcb then the electronics drive the motor transistor, by linking out the transistor the motor is directly connected to the battery voltage, so will run untill the battery runs out, no electronics or monitoring will be carried out by doing so. please note the trigger switch will not function, so will need re wiring see later how i did this.

also you can see the following:

1. the battery voltage wires head off direct to the pcb mounted on the motor.

2. the battery pack thermistor wires connect to the base pcb.

3. the charge bracket connector wires go to the base pcb

4. trigger switch is wired to motor pcb though non ground wire can be seen heading off to the base pc via the grey ribbon cable linking the two pcbs together.

5. magnet sensor ( hall effect switch) is on the base pcb, there is talk on the web, removing this and linking two points will cure the no start up problem, if all else is working though.

Step 4: Photo Showing Pcb Mounted on Motor

photo showing pcb mounted on motor along with details of some parts etc,

note: the mosfet transistor is the only link to engage the motor to battery voltage.

Step 5: Diagram Showing How to Use the Trigger Switch to Directly Power the Motor

diagram showing how to use the trigger switch to directly power the motor, with out any monitoring circuit connected, this is ideal if you want to provide external power to the dc16,

note no charging will function as that is dealt with the pcb circuitry, i chose to deal with that externally by using an 18650 universal charger , more on next step.

Step 6: External Box Added to Battery Box

external box added to battery box, original battery pack cells had been removed, leaving the thermistor in place.

this design could allow you to use removable 18650 cells in a non modded dc16 due to leaving the thermistor in place, though you would have to locate onto one of the cells in the new battery box ( for heat monitoring).

next step shows more info on the battery box.

Step 7: More Detail on External Box Add On

the diagram shows options for either adding 6 qty 18650 battery tray to box or simply forget battery option, i connected a 20v 6A laptop power supply with some mains lead from the laptop psu dc side to the external box.

warning: do not attempt to connect both as you can not charge batteries directly this way.

given the original design was only to provide 6 minutes of run time, i guess due to the current draw from the 6 qty in series 18650 batteries, either because they heat up or they simply run down.

another option maybe you could use as a lorry vac, as the lorry voltage is 24v, though ive not tried this, maybe leash new life in these old vacs.

i find the method of using a laptop psu on a long lead works well.

please note electronic knowledge is recommended when dealing with such as this, especially with li-ion batteries.

Step 8: Photo Shows Using a Laptop Psu, to Power the Dc 16

photo shows using a laptop psu, to power the dc16.

hope you find this info of use.

please note electronic knowledge is recommended when dealing with such as this, especially with li-ion batteries.

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