Black & Decker CMM1000 5HP cordless lawn mower battery service

[A. H. G.]

I have a Black & Decker CMM1000 5HP 24V cordless lawn mower for many years. I heard this is also sold by Sears as model #900.370520.

Now this mower stalled a few times mowing same 50'x 30' backyard.

Can you tell me if I can add fluid to this 24V battery (lead acid ?)?

Can you tell me where to find replacement of this battery?

Thank you.

[Joseph Meehan]

It appears it is a lead acid battery. I found one for $119.00 Check around.

I suggest you remove it, check the acid level and you should be able to have an auto parts store check it out for you.

Just out of curiosity how old is your battery? I just bought one of those mowers this year. I have not peeked at the battery yet.

[A. H. G.]

This 24V 20Amp Battery I found at are quite expensive:

1. InterState Batteries, #AT00L911, 9
2. Ace Hardware, ACE# 29604001, 9

Is there any good way for me to test, which is the real problem, the battery or the motor?

Thank you.

[A. H. G.]

Thank you, Joseph.

We got this mower is around 1998 from Home Depot. They no longer have it. Can you tell me where you purchased your battery? Can you post a picture? Is this battery sealed?

Also, I am unable to unscrew to remove to sharpen the blade. Can you tell me I should turn the nut counter-clockwise to unscrew, correct?

[Joseph Meehan]

I have not yet purchased a battery for it. I just looked for one on the web. I found:

It appears that the battery is sealed, but I am not certain. The instructions do not include much in the way of battery maintenance.

I believe it should turn so that when the mower is running it will tighten the blade. I have not removed mine as I have just bought the mower and only used it once.

[Rich Greenberg]

If its low, add only distilled water.

I got a good deal on a replacement battery for my UPS from Battery Jack. Best price of the many places I checked.

[Rich Greenberg]

[...]

It may be a left hand thread. Try both ways. Do you have an owners manual? It should say if so.

[Joseph Meehan]

I just looked at mine and I could not tell by looking. The manual shows it loosening counter clockwise from the bottom, that is the standard direction for most bolts. My manual is for this years model so yours could be different.

[A. H. G.]

Thank you Joseph. Received reply from ACE Hardware. They do not have this battery in stock, if ever.

[A. H. G.]

Rich, I got no owner's manual for this lawn mower anymore, after several moves. Can anyone out there help which way to turn to remove the blade?

Also, any good way to identify my weak mower (with frequency stalls at high grasses, but wait a few minutes and can restart) is problem of battery or motor?

Thank you.

[Rich Greenberg]

[...]

Try it both ways.

Could be battery, could be motor overheating. Have you lubricated the motor bearings? Look on the manufacturer's web site. You may be able to d/l the manual or call tech support.

Can you run it with a voltmeter on the battery? See if the stalls show the voltage dipping.

[Joseph Meehan]

I seem to recall a motor rebuild kit that replaces brushes and a few other parts.

[A. H. G.]

OK, I toke the lawn mower apart.

Battery: two in series, 12V 17.2AH sealed lead acid battery. Yuasa-Exide, Reading, PA. 19612, Part Number YLM18-12.

The motor top has two copper type of brushings. The brushing holder is spring loaded, and screw mounted. It seems the brushing can be replaced. The width of the brushing is half inch. Any where I can get replacement brushings?

Finally able to unscrew the blade (18 inches long), counter-wise to unscrew. Cut my knuckle. Will get a replacement blade at Amazon.com.

Still do not know best to test if the motor or battery has problem? Thank you all for your advise.

[Tony Hwang]

Hi, Battery can be tested with meter and a 12V light bulbs. Are brushes worn out? Is the commutator show a sign of groove?

[A. H. G.]

Well, brushes seems still quite a bit left. But if I know where to get new ones, I would easily replace it. The motor commuatator looks OK. I know of wipe and clean it a bit. Meter measurement of batteries seems OK. But cannot test how strong is the charged current.

[A. H. G.]

I am seeking motor brushing to replace this pair. This is spring-loaded, and can be remove by unscrewing the plastic holder. The brush width is half inch.

However, went to Home Depot & other local home improvement hardware store, they sell none of this.

Anywhere I can find this in Silicon Valley?

[krw]

Have you tried B&D's web site?

A motor, power tool or small appliance repair shop would likely be the best place.