Reviving a free, dead 12V cordless Black & Decker mower - Page 7

ndukszta · 08-01-11, 09:24 AM

Hello Metro MPG - have the same awesome mower....lost the charger and they don't make it anymore. Any ideas on where I can find one?

MetroMPG · 08-01-11, 09:35 AM

You could use any 12 volt rated "wall wart" style of charger that is rated to output about the same power - 1.7 amps in this case:

This charger actually puts out about 20 volts, open circuit (not plugged in to any load) says my voltmeter.

You might even be able to use a standard car battery charger if it has a 2 amp "trickle" setting on it.

You would just need to get/make a male connector to fit the female one on the mower (and test to make sure you get the polarity right when wiring it).

FYI, you probably already know this, but it's very important for the health of the mower's battery (any lead acid battery, really) that you don't let it sit partially discharged.

Daox · 08-01-11, 10:11 AM

If you do go with an aftermarket charger (thats what I would do), I'd highly suggest a Soneil charger. I have them on my battery electric riding mower and LOVE them. The price on a 2A charger is a very reasonable $38. I also bought my chargers from the vendor I've linked to and he was extremely helpful even when I had issues.

Ryland · 08-01-11, 06:58 PM

Make sure that any battery charger you get is designed for lead acid gel batteries as they do not like to be over charged, batteries like that are more and more common for motorcycles so that would be a place to start.

MetroMPG · 08-01-11, 07:13 PM

Good point.

The OEM charger for this mower is actually "dumb" - it will put out ~1.7A at ~20v until the cows come home.

However, voltage monitoring happens on the mower's circuit board: when it rises to whatever threshold it deems high enough, current is shunted to a finned resistive load/heat sink thinger to protect the battery.

So you should be good to get another cheap, dumb charger (if cheap and dumb suits you).

RobertSmalls · 08-01-11, 08:03 PM

Quote:

Originally Posted by MetroMPG

Good point.

The OEM charger for this mower is actually "dumb" - it will put out ~1.7A at ~20v until the cows come home.

However, voltage monitoring happens on the mower's circuit board: when it rises to whatever threshold it deems high enough, current is shunted to a finned resistive load/heat sink thinger to protect the battery.

So you should be good to get another cheap, dumb charger (if cheap and dumb suits you).

Ugh. The makers of the mower decided it was better to dump 30W all day and night long until you unplug the charger, rather than jack the price up a few dollars for a "smart" charger controller board. It's still better than a gas mower, but upgrading to a smart charger, or putting it on a timer, is low-hanging fruit.

MetroMPG · 08-01-11, 08:58 PM

Ugh is right.

In a manual I found for a similar one, they even say "it's OK to leave your mower plugged in all the time."

MetroMPG · 08-12-11, 02:09 PM

So, the mower's working fine. I've used it 3 or 4 times now.

The only thing it's missing is (1) I need to tidy up the battery pack connections (tape them); (2) secure the batteries better, and (3) reinstall the motor cover.

I also need (4) a way to permanently monitor battery voltage while cutting (necessary if you're using older batteries and you want to prolong their lives as much as you can).

So I just bought a 12/24v digital gauge that I'll mount on the mower ($6.28 US on eBay, with shipping). It's meant to plug into a car cigarette lighter socket, but I'll hack it & mount it on the cover, I think.

Measuring range: DC 8V-30V±%1.2

MetroMPG · 08-12-11, 02:17 PM

Oh, also Mower #2 (the 7A, AC one I picked up partway through this project) is also working fine, at the garage. I've used it 4 or 5 times, powered by the solar setup.

Ultimately I'd like to put up my spare 1A panel and use it to recharge this battery mower, so they're both grid-free & gas free.

MetroMPG · 08-12-11, 02:22 PM

OH! And an update on Mower #3 - the spare, identical M3300 battery mower I picked up "for parts"...

I fixed its charger - it was a short circuit (sloppy manufacturing) that blew the internal fuse.

Aside from "jump starting" the mower it to see if the switch/motor works (it does), I haven't stuck batteries in it to try mowing with it.

I have too many lawnmowers. I have backups for my backups.

Just need a goat to round out the fleet.

08-01-11, 09:24 AM	#61
ndukszta Lurking Renovator Join Date: Aug 2011 Location: Toronto Posts: 1 Thanks: 0 Thanked 0 Times in 0 Posts	Need charger for M3300 Hello Metro MPG - have the same awesome mower....lost the charger and they don't make it anymore. Any ideas on where I can find one?

08-01-11, 09:35 AM	#62
MetroMPG Infrequent noob Join Date: Aug 2008 Location: 1000 Islands region, Ontario, Canada Posts: 402 Thanks: 37 Thanked 20 Times in 19 Posts	You could use any 12 volt rated "wall wart" style of charger that is rated to output about the same power - 1.7 amps in this case: This charger actually puts out about 20 volts, open circuit (not plugged in to any load) says my voltmeter. You might even be able to use a standard car battery charger if it has a 2 amp "trickle" setting on it. You would just need to get/make a male connector to fit the female one on the mower (and test to make sure you get the polarity right when wiring it). FYI, you probably already know this, but it's very important for the health of the mower's battery (any lead acid battery, really) that you don't let it sit partially discharged. __________________ . To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-01-11, 10:11 AM	#63
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	If you do go with an aftermarket charger (thats what I would do), I'd highly suggest a Soneil charger. I have them on my battery electric riding mower and LOVE them. The price on a 2A charger is a very reasonable $38. I also bought my chargers from the vendor I've linked to and he was extremely helpful even when I had issues. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-01-11, 07:13 PM	#65
MetroMPG Infrequent noob Join Date: Aug 2008 Location: 1000 Islands region, Ontario, Canada Posts: 402 Thanks: 37 Thanked 20 Times in 19 Posts	Good point. The OEM charger for this mower is actually "dumb" - it will put out ~1.7A at ~20v until the cows come home. However, voltage monitoring happens on the mower's circuit board: when it rises to whatever threshold it deems high enough, current is shunted to a finned resistive load/heat sink thinger to protect the battery. So you should be good to get another cheap, dumb charger (if cheap and dumb suits you). __________________ . To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-01-11, 08:58 PM	#67
MetroMPG Infrequent noob Join Date: Aug 2008 Location: 1000 Islands region, Ontario, Canada Posts: 402 Thanks: 37 Thanked 20 Times in 19 Posts	Ugh is right. In a manual I found for a similar one, they even say "it's OK to leave your mower plugged in all the time." __________________ . To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-01-11, 06:58 PM	#64
Ryland Master EcoRenovator Join Date: Mar 2009 Location: Western Wisconsin. Posts: 913 Thanks: 127 Thanked 82 Times in 71 Posts	Make sure that any battery charger you get is designed for lead acid gel batteries as they do not like to be over charged, batteries like that are more and more common for motorcycles so that would be a place to start.

08-12-11, 02:09 PM	#68
MetroMPG Infrequent noob Join Date: Aug 2008 Location: 1000 Islands region, Ontario, Canada Posts: 402 Thanks: 37 Thanked 20 Times in 19 Posts	So, the mower's working fine. I've used it 3 or 4 times now. The only thing it's missing is (1) I need to tidy up the battery pack connections (tape them); (2) secure the batteries better, and (3) reinstall the motor cover. I also need (4) a way to permanently monitor battery voltage while cutting (necessary if you're using older batteries and you want to prolong their lives as much as you can). So I just bought a 12/24v digital gauge that I'll mount on the mower ($6.28 US on eBay, with shipping). It's meant to plug into a car cigarette lighter socket, but I'll hack it & mount it on the cover, I think. Measuring range: DC 8V-30V±%1.2 Attached Thumbnails __________________ . To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-12-11, 02:17 PM	#69
MetroMPG Infrequent noob Join Date: Aug 2008 Location: 1000 Islands region, Ontario, Canada Posts: 402 Thanks: 37 Thanked 20 Times in 19 Posts	Oh, also Mower #2 (the 7A, AC one I picked up partway through this project) is also working fine, at the garage. I've used it 4 or 5 times, powered by the solar setup. Ultimately I'd like to put up my spare 1A panel and use it to recharge this battery mower, so they're both grid-free & gas free. __________________ . To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-12-11, 02:22 PM	#70
MetroMPG Infrequent noob Join Date: Aug 2008 Location: 1000 Islands region, Ontario, Canada Posts: 402 Thanks: 37 Thanked 20 Times in 19 Posts	OH! And an update on Mower #3 - the spare, identical M3300 battery mower I picked up "for parts"... I fixed its charger - it was a short circuit (sloppy manufacturing) that blew the internal fuse. Aside from "jump starting" the mower it to see if the switch/motor works (it does), I haven't stuck batteries in it to try mowing with it. I have too many lawnmowers. I have backups for my backups. Just need a goat to round out the fleet. __________________ . To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.