here is some info on 20v yardworks lithium ion

My 2 new bats are 19.62v. out of the box from CT ( I did not charge these ones yet )

The other 2 when freshly charged are at 20.9v. All cells balanced at 4.18v.

I used to charge after every ride. They were always less than 0.1v. apart after short rides and 20.9v. freshly charged.
After a few rides without charging, ( Last ride today ) they were at 17.70v. and 18.08v.
First bat cells: 3.54, 3.56, 3.53, 3.56, and 3.51
Second bat cells: 3.61, 3.63, 3.62, 3.62 and 3.60
They're back on the charger to see if they will balance the cells.
Original BMS and charger used.

I noticed the s.o.c. leds don't work anymore on both batteries.(???) Did the serial connection killed it ?
And why the voltage difference (???) they are used in serial for 36v. They were both at 20.9v to start.
 
First, a correction. s.o.c. leds are ok after I recharged the batteries, they show a full charge (all 4 leds).

Both batteries are at 20.9v. out of charger with cells at 4.18 and 4.19 except one at 4.17 on the battery that was 17.70v.
So that cell that went 0.05v. apart ( 3.51 compared to highest at 3.56 ) is now only 0.02v. from highest at 4.19v.
I don't know if it's good balancing or not , but at least, it shows some balancing. :?:

As for the s.o.c. indicator, that's the part of the battery you can't trust. :lol:
 
Hey all, long time no post ! :)

So did this thread die ? As mentioned in my Arduino Charger/BMS thread I went kinda manic on that project in the late fall, and that contributed to a bout of depression that resulted in my leaving my job on disability, and I wasn't able to get much else done either... But I'm feeling much better now and may be returning to work soon.

I've been ebiking just a few times so far this year. I'm currently using 4 intact Yardworks batts in serial, with original BMSs, cases and all. Because of the size, compared to bare cells, I've moved them from the center of the bike to a rack on the back. I'm thinking of having 4 yardworks chargers connected more or less permanently to the charging terminals of the batts to allow on bike charging.

I'm still very much interested in some sort of charging, monitoring, BMS solution using some combo of the TME balancers, 1 or more Arduino micros etc. But for now, I'm going to tread lightly down that route.

I still have 9 YW batts that are relatively fried and just begging for warranty replacements. Anyone had any hassles with that ? I wonder if CT just chucks them in the landfill or if they are trying to rebuild them or whatever.

Any other news of any interest in the YW batt world ? I see there are some other options for batts now and with new price levels and the value of the Canadian dollar, perhaps the YW batts are a bit less compelling now ?

Cheers !
Mike.
 
mikereidis said:
.... I'm thinking of having 4 yardworks chargers connected more or less permanently to the charging terminals of the batts to allow on bike charging.
Mike.
Click to expand...
Welcome back Mike,

Mine are connected permanently but switched on the + side.
So if a BMS cuts off, the current won't try to go by it's charger.
 
Takemehome said:
mikereidis said:
.... I'm thinking of having 4 yardworks chargers connected more or less permanently to the charging terminals of the batts to allow on bike charging.
Mike.
Click to expand...
Welcome back Mike,

Mine are connected permanently but switched on the + side.
So if a BMS cuts off, the current won't try to go by it's charger.
Click to expand...

Thanks Takemehome...

Hmmm, so do you only switch the + terminal of charger to + of the batts when charging ?

I haven't tried a permanent charger hook up yet, but I would have thought that, BMS cut off or not, this would be pretty much equivalent to having the YW batt in a YW charger with the 120 VAC disconnected. I figure this would be benign, even if pulling a load.

Have you seen or heard of a problem that would require such switching, or are you just being cautious ?

I got curious about the battery/BMS/charger setup in your sig and found your "Yardworks and Konions = Great Team" post at: https://endless-sphere.com/forums/viewtopic.php?f=14&t=9981&p=153923#p153923

Interesting... Still working well ?
 
mikereidis said:
.....Have you seen or heard of a problem that would require such switching, or are you just being cautious ?
Click to expand...

Being cautious.
Switches are cheap, a 2PST is $0.99
$1.98 for 4 chargers and peace of mind.

mikereidis said:
I got curious about the battery/BMS/charger setup in your sig and found your "Yardworks and Konions = Great Team" post at: https://endless-sphere.com/forums/viewtopic.php?f=14&t=9981&p=153923#p153923
Interesting... Still working well ?
Click to expand...

Yes sir, and perfectly balanced after +- 20 cycles.
Fully charged 4.15v~4.16v all 10 "BIG CELLS" :lol:
I checked twice, after long rides, and cells were equally discharged.

Note that I rebuild my 4 packs to be only 2 big ones.
I only use two BMS now.
Each BMS monitor 5S( one)P ( 2 YW cells and 10 K cells as one BIG CELL)
I also connected my chargers in parallel to charge each pack at ~4 Amps

You see my avatar ?
2x 18.5V.27Ah. Packs
4 chargers with a fan
regen braking (3 bridges) and controller
All in my front bags hiding the motor.
 
Hi Mike welcome back
I returned all my 6 YW packs and got refunded and purchased 6 more online for a new 1 year warranty.
To get refund instead of replacement (which doesn't extend warranty) you have to make sure the store you return to doesn't have them in stock.
When you return no ID is required just a phone number, they don't even test the batts to see if they function or not.
The returns clerk told me they crush the YW returns seems dam dangerous to me !
9 is allot to return, think i would split it into two returns.
good luck
 
29a said:
Hi Mike welcome back
9 is allot to return, think i would split it into two returns.
good luck
Click to expand...

Hi 29a. Heck, I was debating 4 returns vs. 3 returns. Wouldn't even consider 9 in one return.

Yeah, I was aware of the cash refund if they aren't stocked. Hadn't thought of return and rebuy to extend warranty though... :mrgreen: One small store in Bells Corners had no battery stock for most of the summer last year, and I saw stock get low or disappear at other stores in the fall.

I imagine that CT will move to a new type of battery, and new tools at some point in the future, but that could take years.

Was reading that lithium batteries always degrade over time whether used/cycled or not; related to the fact they must always have a charge. But yes, somewhere around half charge is a sweet point to extend life when not used.

Seems wasteful to me that they crush them, but I imagine some bean counter somewhere figured that was best, given the expected warranty return rate. Makes the hypothetical "fill the cases with rocks and return" scenario more plausible.
 
Takemehome said:
mikereidis said:
.....Have you seen or heard of a problem that would require such switching, or
Note that I rebuild my 4 packs to be only 2 big ones.
I only use two BMS now.
Each BMS monitor 5S( one)P ( 2 YW cells and 10 K cells as one BIG CELL)
I also connected my chargers in parallel to charge each pack at ~4 Amps
Click to expand...
Click to expand...

So I presume you parallel each individual cell ? IE. in addition to the main terminals you run 4 cell paralleling wire runs for each 5s (5 cell) battery ?

If so how did you hook to the cells ? I did some cell hookups by various methods in order to bypass bad cells, but it was ad-hoc and wasn't that pretty looking or confidence inspiring. The stock small gauge cell monitor wires don't seem capable of handling much current, but probably wouldn't need to if all the cells between batteries are reasonably well balanced.
 
I started by the 2 YWs in parallel 5S2P balanced 4.16v. 20.8v
Built the Konion packs 5S10P balanced 4.15v.~4.17v. 20.8v.
Then parallel them, kind of 5S12P.

"The stock small gauge cell monitor wires don't seem capable of handling much current, but probably wouldn't need to if all the cells between batteries are reasonably well balanced."

That's right. I used same gauge to join the Konions for monitoring.
The only big wires are joining all the cells #1 POS. and all the cells #5 NEG.
In the monitor wires, there's not much circulation there, only a few miliamps from stronger cells to weakest cells if any.
That's why it's good from time to time to check if all groups of cells are balanced. If not, it means a cell is weak and bringing the group down. The YW BMS does not balance. But AFAIK LiMn don't need to. It seems Fatpacks don't even have a BMS.
 
Takemehome said:
I started by the 2 YWs in parallel 5S2P balanced 4.16v. 20.8v
...
If not, it means a cell is weak and bringing the group down. The YW BMS does not balance. But AFAIK LiMn don't need to. It seems Fatpacks don't even have a BMS.
Click to expand...

Cool, yes, as long as the LiMn is in good shape... :) (Unlike many of mine.)

I finally got around to testing out my 5 TME Xtrema balancers/cell monitors. At 0.1" the pins fit nicely into the BMS cell monitor connector on these YW batts, though I'm not sure the pin thickness is an exact match.

I was disappointed to see cell 5 go up in apparent voltage as the balancing continued. Checked their forum and found, hidden in a message about new firmware, that they have "...two resistors that have inconsistent temperature coefficients...": http://tmenet.com/forums/index.php?topic=318.0 . At least they've found and acknowledged the problem, and will take returns, but I'm surprised they didn't catch or announce the problem long ago. I presume they'll just send new boards and throw out the old; can't be worth it to deal with replacing surface mount resistors I imagine.
 
nutsandvolts said:
.....The yardworks battery hunt:....., no yardworks batteries in stock.
Click to expand...

Patience my friend, fall is the hunting season. :D

Remember last fall they went down at $110.


About the rain suit: get some reflective bands because "navy" is almost invisible in the rain especially at night.
 
nutsandvolts said:
I bought all the yardworks batteries in town (five locations), and even reprimanded canadian tire store staff for dwindling supplies. They cut off my supply! :shock:
Click to expand...

Here's a thought for when you want to return old batteries for cash (someone said if you are returning
a battery under warranty and they don't have any in stock at the store that you go to, they give you
cash back). If you're planning on getting more batteries, just buy all the stock first, then return the
old, or tired, or fried (charred remains stuffed back into a case as someone put it) batteries.
 
i return my yw batteries every year without a wimper from ct
how is that fraud?
they have a warrenty and i use it...
i've had ct deny me being able to use ct money for gas at their
gas bar...so i use the ct money buy a ct gift card from the same gas teller and then buy my gas with the gift card the look on their face is priceless...jmo
 
again how is it fraud?
maybe they were defective how would i know i'm not a technician
you seem to want to instill YOUR morals onto others
if ct had issue they would change their return policy like they did on gps's
again jmo so enough with the moral's if people feel bad don't do it
it's ct's warrenty...almost as good as walmarts return policy
 
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