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

I am sure each battery pack has it's own BMS so you could parallel charge them without issue. And even if you didn't have them at the same charge rate the BMS in the pack would cut out one pack without affecting the other.
 
I'm running two of these in parallel now. Also added two 18v batteries for more voltage. I found a source for the parts that would be in a charger or most tools for battery connection.

The "insert block" is the connector. That sits in the holder, which locks in place on the battery. Kind of pricey especially for the insert block. With shipping it was about $30 for three sets (have an extra if I want to add on later.) Note that this insert block is for the old style battery, so a groove needs to be cut on the sides in order for the g-max batteries to lock in... easy enough with a hand saw. The block sits pretty snugly in the holder so I just hot-glued it in place.

http://www.m-and-d.com/GRN-34106976.html
http://www.m-and-d.com/GRN-34104488.html

IMG_20140413_213958712.jpg
IMG_20140413_213828181.jpg
 
jk1 said:
What is the sag like at 40Amps ?
Click to expand...

What is the proper way to find the sag voltage? Do I charge it up and then load it at 40A to find the voltage drop?

Then
Sag Voltage = Charged Voltage - Voltage at load
I'm not sure I could find it accurately since I find it difficult to consistently load the bike at 40A
 
i just ride normally and check the v drop pulling away from a stop. don't look for an exact number, look for the normal range. i throw out the best and worst if they are rare.
.
a bench test might be more scientific, but what does is prove? riding around is the real world. WYSIWYG.
 
I took the battery to around 27V. The BMS didn't shutdown and it kept powering my CA3 but there were no juice left to power the motor. CA3 is telling me that I drew 3.5Ah; I will probably get another one to parallel up.
 
good idea to parallel packs. sag converts power into heat. the 3.5ah will improve with half the sag of double packs.
i'm going to put my 2 dewalt packs in my ebike, along with 4 makita for near 10ah. will charge to 4-4.10 for long life. each .1v drop is said to double cycle life. that may be how GW claims 2000 cycles. 500@4.2, 1000@4.1 2000@4.0
 
If you don't want to buy an "insert block" can you use 5/16 inch spade connectors to tap the power? Can you charge these with a standard charger through the same terminals that you discharge (is the bms + and - the same for both input and output)?
 
Gregor said:
If you don't want to buy an "insert block" can you use 5/16 inch spade connectors to tap the power? Can you charge these with a standard charger through the same terminals that you discharge (is the bms + and - the same for both input and output)?
Click to expand...
I am just plugging spade connectors into the battery for now. I will probably machine an insert block later. The charger has 4 spades which plug into the battery but I don't know if those are actually used or not. I am able to use regen with the battery so I guess it should be possible to charge from the postije and negative only.
 
I think the inner 2 connectors (those that are not marked with a "+" or "-") are for monitoring battery temp at least on charging--of course I could be wrong--I just use the outer 2 connectors. I think the factory charger puts out about 1.8 amps, so to charge the 4ahr unit it takes a while. At least copmared to hobby rc lipo packs, you can hook it up and just go to bed...
 
pixelpusher said:
bluovalguy said:
I found a source for the parts that would be in a charger or most tools for battery connection.
Click to expand...

Found another site for the parts that's slightly cheaper here:
http://www.ordertree.com/greenworks/catalog/product/view/id/61920/s/sun-34106976/
http://www.ordertree.com/greenworks/catalog/product/view/id/65604/s/sun-34104488/
Click to expand...

Nice find!

Gregor said:
I think the inner 2 connectors (those that are not marked with a "+" or "-") are for monitoring battery temp at least on charging--of course I could be wrong--I just use the outer 2 connectors. I think the factory charger puts out about 1.8 amps, so to charge the 4ahr unit it takes a while. At least copmared to hobby rc lipo packs, you can hook it up and just go to bed...
Click to expand...

That's correct. The chargers aren't even wired to the main +. It charges off one of the middle terminals, and the other is temperature I believe.
 
did everybody here simply use - & + outer tab to get the power from this battery ?

i also want to use these 40V pack for both my mower & my bicycle but outer connector tabs
didnt provide full votage ?

my elec bike can pull 27amp peak but i might limit this to 20amp
if a 5C usage help the battery life cycle...

did everybody here simply use - & + outer tab to get the power from this battery ?
 
see attechec pics...

anybody know what to do to get the power out of this battery ?
when i plug it in the charger, the - and + become alive ... but
if i mesure with the battery on its own i get nothing... -+ slowly drop ?

when pluged to the charger:
-- 1 and 4 reach 42.2V (fully charged)
-- 1 and 2 also get 42.2V
-- 3 and 1 has 0.821 V
-- 3 and 2 has 41.4 V (3=negatif 2=positiv)

i think i might have to jump 4+ to 2 to feed the BMS
and activate the output ?
DSC00256_.JPG


charger config using only center tab and -
DSC00253_.JPG
 
skeetab5780 said:
silly people and their warranties...
Click to expand...
LOL :?

i presume you mean tamper with ? what we do here is R & D with low budget and i think
GreenWorks will actually benefit from our experience ? yes maybe some user will break
things and sent them back for warenty ? some people even disasemble things and remove
content and go back to the store for refund ! this is pure stealing :oops:

if we find an easy way to use these 40V battery pack with various elec. bike...toy...tool...
they will actually sell more battery and even sell mower & tool combo because people will
have many usage for GreenWorks product ! after all... the company commitment say it all :
http://greenworkstools.ca/environment so they should support us with multi usage...

DONE ! i find the way to use the battey as is... activating the BMS and get the voltage
output without opening... simple et cheap connection...

about real C & voltage drop :
Ryobi 18V 4ah pack x 2 get me 40V and drop to 35V with 27 amp (5 volts drop)
GW 40V 4ah get met 41V and drop to 37V with 27 amp (4volts drop)
test done with my 1000watts Magic pie http://www.goldenmotor.ca/products/Magic-Pie-4-%28VECTOR%29-700c-Rear-Conversion-Kit.html

http://greenworkstools.ca/products/group/DigiPro-40V-lithium-ion
i would like to grab the blower and get another battery... :wink:
 
Warning to anyone using these batteries... They have no internal LVC whatsoever. I accidentally left them connected to the bike with controller on for almost a month. They drained to 1.5v total pack voltage and would not take a charge. Thought they were bricked, but was able to nurse them back with a 12v trickle charger enough to take a charge on the greenworks chargers. Seem to be doing fine now with no noticeable loss in full voltage or capacity.
 
bluovalguy said:
Warning to anyone using these batteries... They have no internal LVC whatsoever. I accidentally left them connected to the bike with controller on for almost a month.
Click to expand...
Not totally true Bluovalguy : they have an LVC and my bike shut down at approximatly 33-34V ... i suspect a wrong custom made battery adapter wich had kept the BMS on for that month ?

everybody buy these Tools with plugged battery wich would ran the company bankrupt it they all discharge to zero !

When you make your own "custom" adapter , you need a switch that will turn off the battery BMS and voltage feed
if you leave it unused for extended time ...
if not, your BMS "standby" current will probably drain your battery in the long term like it happend to you...
 
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