How to test this 24v 13" Worx Mower

[juntjoo]

I tried testing with a Milwaukee 18v figuring I might get something got nothing nor did I get any ohms from it. I tested it from two positions of the only switch I found on it.

No reading for resistance usually means it's dead no? It's an old model.

 

[kellys_eye]

nor did I get any ohms from it.

I tested it from two positions of the only switch I found on it.

Meaningless. Show where you made a measurement, how you did it and the results you got.

A 24V device won't work with an 18V battery. At best it will cause an over-current situation and the built-in battery protection would cut off the power from the battery anyway.

The battery terminals may not even match.

 

[juntjoo]

Meaningless. Show where you made a measurement, how you did it and the results you got.

A 24V device won't work with an 18V battery. At best it will cause an over-current situation and the built-in battery protection would cut off the power from the battery anyway.

The battery terminals may not even match.

In the pic with the terminals is where I connected a multimeter. I don't know any other way to test ohms

What do you mean they may not even match?

How would you go about testing this without a 24v battery?

Could I somehow get it from the wall?

Actually I DO have variable voltage supply with various connecting tips I got for testing I didn't think of trying. I believe it goes up to around 24v. Will have to double check and would have to put something together to adapt it to connect to those possibly mis-matching terminals

What do you suggest?

 

[kellys_eye]

I couldn't fathom the images you posted - until now! Now that I 'see' what you've done you say you aren't measuring anything across the terminals where the genuine battery should connect? Is that with the switch in the run position? If so then maybe the switch is defective or the motor is open circuit.

The motor is potentially a brushed commutator and the brushes likely worn to the point of none contact so they would be another thing to check. Replacement brushes should be readily available.

Still, those portable tool batteries have internal over-current protection and may be cutting off - simple tes though, measure the battery voltage whilst switching the thing on. If it stays the same then the motor/switch need checking.

 

[juntjoo]

I couldn't fathom the images you posted - until now! Now that I 'see' what you've done you say you aren't measuring anything across the terminals where the genuine battery should connect? Is that with the switch in the run position? If so then maybe the switch is defective or the motor is open circuit.

The motor is potentially a brushed commutator and the brushes likely worn to the point of none contact so they would be another thing to check. Replacement brushes should be readily available.

Still, those portable tool batteries have internal over-current protection and may be cutting off - simple tes though, measure the battery voltage whilst switching the thing on. If it stays the same then the motor/switch need checking.

As far as that other switch, duh. Didn't see the forest through the trees. I'll take your advice in a bit here and report back...

 

[kellys_eye]

Is that a throttle?

 

[juntjoo]

Is that a throttle?

I assume so or binary switch. My eyes are bad, but it's that lever and a "power/quiet" switch on the top there.

So am I doing this right? I in fact got a resistance reading, some K ohms squeezing the hand lever. I don't know on the mower what's -/+ but I just tried both. I have it all in parallel in case it's hard to see. No draw from the battery reading 20v actually(18v battery).

Should I have jotted down the exact ohms?

Would a variable power supply over 24v be a useful tool? I think mine broke, want to order another for general testing

 

[kellys_eye]

If that motor ever starts running those croc clips/wires will be smoked almost immediately!

Assuming a 'throttle' then we're looking at PWM speed control. This is adding another layer of stuff between the battery and the motor and another potential point of failure. Time to take the covers off and look closer.

 

[juntjoo]

If that motor ever starts running those croc clips/wires will be smoked almost immediately!

Assuming a 'throttle' then we're looking at PWM speed control. This is adding another layer of stuff between the battery and the motor and another potential point of failure. Time to take the covers off and look closer.

yeah, I figured that was possible, planning on getting fatter wires. Okay will be back later...

 

[Bluejets]

The motor is potentially a brushed commutator and the brushes likely worn

The Worx mowers use brushless motors with 2 x 40v batteries, most likely lithium or LiPo.
So therefore brushless motor controller and not much point poking around trying to measure resistance with a multimeter.

 

[juntjoo]

Why not?

 

[juntjoo]

The Worx mowers use brushless motors with 2 x 40v batteries, most likely lithium or LiPo.
So therefore brushless motor controller and not much point poking around trying to measure resistance with a multimeter.

Where did you get the info and why do you say 40v and not 24v?

Just watched it a couple videos on it and it has three states, trigger pulled + "quiet" | "power" or no trigger. So technically speaking do all I need to do is get 24v to the terminals and pull the trigger to test it?

 

[ivak245]

The "trigger" is more likely a "dead man's switch". I rescued a similar mower and that switch was O/C, so I just bypassed it. If you use your external supply to fire it up, it should be at least able to handle 3 or4 amps.

 

[Martaine2005]

What model is it?
The WG778E uses 2x20v = 40v.
Show a picture of where the battery or batteries slide on.

Also quite possibly has two ‘dead man’s’ switches so only can be used with two hands.

 

[juntjoo]

What model is it?
The WG778E uses 2x20v = 40v.
Show a picture of where the battery or batteries slide on.

Also quite possibly has two ‘dead man’s’ switches so only can be used with two hands.

This is the WG782. I couldn't even find it on their site.

 

[Martaine2005]

That model is indeed a 24V lead acid battery.
I believe it dates back to about 2012?.
The battery looks to be quite large too. Do you have the old battery to supply us with the specs?
Edit:
Battery = WA3216, 24V, 5Ah
Charger = WA3721

 

[Martaine2005]

 

[juntjoo]

That model is indeed a 24V lead acid battery.
I believe it dates back to about 2012?.
The battery looks to be quite large too. Do you have the old battery to supply us with the specs?
Edit:
Battery = WA3216, 24V, 5Ah
Charger = WA3721

No, don't have a battery. Just found the mower on the side of the road, figured I'd see if I could test it then sell it. Thanks for the link.

 

[Martaine2005]

If you have two 12V batteries, connect them in series.

 

[juntjoo]

If you have two 12V batteries, connect them in series.

I do! I have m12 and m18 Milwaukee batteries. Didn't think of that.