Greenworks 40v G-MAX disassembled- 11C rating?

[bobdill]

1N4001

I have put only 1 big diode found in a old power supply... Working perfectly!! tkx

 

[ziggy90127]

I took apart a Greenworks 40V battery Model 29662 (60-1758) 146Wh, date code 01/08/17. It has 20 x Sanyo UR18650RX U37A. Other numbers on each cell: "A UHL9RXD 123 27278 3626V".

This new battery died suddenly in a Greenworks 40V 8-Inch Cordless Pole Saw after only a few minutes of light use (the second new battery it killed in this manner). The battery shows 4 green leds when the status button is pressed. When in the charger, the charger shows a green led, full charge. Measuring the voltage in the pole saw shaft shows 24V dropping quickly to 4V.

The bms pcb has a heat sink attached, with 3 - TO-220 devices attached. I was hoping one of these devices would show being dead, and thus an easy fix. I dug off the white potting compound with non-conductive wood and plastic utensils. The B+ and B- terminals to the batteries show 39V. I first desoldered the B- negative terminal using a soldering gun and Chip Quik Alloy, being careful not to short anything out on the live battery! This doesn't completely disarm the battery as the balance wires are still connected (connector glued on pcb with potting compound). Then I desoldered the heatsink and devices being careful not to short anything out on the live battery! On the heat sink there are 2 N-Channel FET's (ME80N08A)(pcb says Q29 & Q32), and 1 dual diode, common anode (FR1003A)(pcb says D7). I used an ohmmeter to test them, and they passed, so the problem seems to be elsewhere. I guess the bms pcb is a writeoff. Numbers on the bms pcb: 26R8028(R8-10S2P-SXJ-1-C) R8-10S2P-SXJ T63XB-04.

I've returned the cordless pole saw and bought a corded one. Attached are battery pictures for your viewing pleasure!

 

[wayneinteressierts]

Hi everyone,

A lot of great info here. Thanks for that!

I picked up a couple of Snapper branded 60v (54v) batteries sold by Walmart but made by Greenworks.I made a mount using Home Depot products but then I stumbled upon this thread and saw that some of you found the part number for the Greenworks insert block. It looks different than the Snapper charger block and I took the charger apart to see if there was a part number but no such luck. I was wondering if you might shed some light on how I can find the part number to order one. Should I just call Greenworks and ask?

Snapper charger:
https://www.walmart.com/ip/Snapper-60V-Charger/651186645

Also, if anyone is interested, the 60v 4Ah batteries are selling for $60 and have been going out and coming back in stock for the past couple of weeks. The "back in stock" email alerts don't work but you can periodically check the page to see. It was in stock the last time 2 days ago.

https://www.walmart.com/ip/Snapper-60V-4Ah-Battery/133185211

 

[markz]

the 60v 4Ah batteries are selling for $60 and have been going out and coming back in stock for the past couple of weeks.

At $15/Ah that is a great deal!
Plus the return policy is unbeatable.
Keep them the way they are and find a way to connect them electrically and secure them.
Depending on the cells used inside each battery, might be wise to place 2 or 3 in parallel depending on your battery discharge requirements. Not only do you get the 4Ah, but if you go 2 in parallel that is now 8Ah and you lessen the load on the battery when its discharging and 3 in parallel is 12Ah and that distance increase is good for $180.

 

[timmy66]

Anyone figured out how to simulate what the 3/4th terminal of the battery is doing?

eg, if wanting to make my own greenworks battery for one of their adapters?

What was the diode doing mentioned above?

 

[JesseW]

Just bumping this thread to see if anyone can give me any help figuring out how to power a Greenworks digipro trimmer with a 48v ebike battery, see thread below. Kind of the opposite of what most people are trying to do in this thread. Since the tools are cheap with no batteries I'd like to run a trimmer and chainsaw off the high capacity ebike batteries I already have. I'd probably put the batteries in a backpack and run a cable to the tool.

https://endless-sphere.com/forums/viewtopic.php?f=1&t=102461

Thanks

 

[wineboyrider]

Just bumping this thread to see if anyone can give me any help figuring out how to power a Greenworks digipro trimmer with a 48v ebike battery, see thread below. Kind of the opposite of what most people are trying to do in this thread. Since the tools are cheap with no batteries I'd like to run a trimmer and chainsaw off the high capacity ebike batteries I already have. I'd probably put the batteries in a backpack and run a cable to the tool.

https://endless-sphere.com/forums/viewtopic.php?f=1&t=102461

Thanks

Metallover and Veloman have a thread that someone posted info on the 40v packs.

 

[wineboyrider]

So I did a boo boo and hooked up reverse polarity to my Greenworks 40v g-max pack and poof the pcb or bms went up in smoke? I have it disassembled and it is showing correct voltage. I have another old battery that I am going to try and scavenge in the hopes that it might be the BMS. There doesn't seem to be an obvious fuse on the board of it though? Any help would be appreciated.

 

[ggtronic]

update : recently open a 150w inverter made by GreenWorks :
the necessary tab connection to provide power from the
negative tab is a simple short as below : this is for the Canadian
GreenWorks battery that has BMS incorporated :
http://yvesauger.com/wp-content/uploads/GreenWorks_adapter.jpg

 

[kram]

I have a couple of Greenworks tools but no battery. It would be great to know what signal is used for the enable pin from the battery, so I can use my lipo packs with it. Without this signal it spins up, then turns off after 1 second.
Other tools its common to have a 10k NTC resistor to negative, but this did not work.

 

[nioko]

@kram

Ever found a solution?
I have two Stiga tools here, that look kinda similar to the greenworks, but use another battery configuration (12s instead of 10s).
https://www.pedelecforum.de/forum/index.php?threads/qualitaet-der-akkus-lgdbhe21865-oder-lieber-andere.84611/

Not sure how to approach it yet.