here is some info on 20v yardworks lithium ion

[mikereidis]

my latest issue is uneven battery lelel's after run...
starting from yw1 20v yw2 20v sla13.60v
after 8km at 45kmh strait no cooling breaks(motor is hot)
ending volts...yw1 16.01v...yw2 18.60v...sla 12.63v
they are wired just as shown and i think the bottom yw bat
is taking the brunt...? i think i will rearange my wires
so sla is bottom bat and see if it takes the hit and my
limn's even out some in discharge? does that make sence?

You have 2 YWs and an SLA in series ?

Unless heat is an issue in physical placement (IE one YW on top of another, or one in the breeze at 45 KMH and one not), physical placement should not matter electrically.

Also presume you have not tapped one YW for lights or something, and the lower YW isn't getting shorted on something occasionally.

Does your DMM only show 1 volt of resolution over 20v ? Because you say 20v each, not 20.8 each for example. 1 batt at 20.7v has a good bit more charge than another at 20.0v, like as much as 20%.

I think ending voltages of 16.0v and 18.6v indicates your high battery has 17% more capacity left.

 

[mikereidis]

BASICLY IMO

YW charger (crap.. don't waste your time)
YW bms (again Crap don't waste your time, I had nightmares with my dewalt bms, I don't trust anything yardworks is going to include with this $109 battery; Use a 3rd party balancer for god sakes; I think a lipo blinky balancer will do a heck of a better job.

Battery testing to come...

p.s. What would you say is a safe charge rate for these cells? What it the safest discharge rate for these batteries also say for a 20s pack?
Have you found any specs on the batteries? I wish i had the battery info here with me just curious to find some info on the cells themselves.

-steveo

Cool ! Wonderful, I'm looking forward to more feedback and detailed testing results.

Yes, charger and BMS, kinda crappy, but not TOO bad (for the price) as baseline or "training wheels" until we get/build some better ones.

Safe ? I dunno, we're doing our own R&D here. In a post in first 2-3 pages the numbers on batts were deciphered to indicate 6 amp-hours (which we already know), nominal voltage 18.5v (normal for 5 LiMn cells) and max discharge rate of 31 amps (5+ C). I've never hit the BMS current limit but I think someone (NutsAndVolts?) mentioned they cut out around 30 amps or so.

IMO, safest, most life enhancing charge or discharge current for any battery is 0 amps, or just slightly more.

There's a nice graph here: http://www.batteryuniversity.com/parttwo-34.htm that indicates 1c charge/discharge might last 500 cycles with 15% or so drop in capacity. 2c might last 200 cycles with same 15% drop, and 3c perhaps 50 cycles. Maybe LiMn is better, I don't recall right now.

EDIT: Oh, here it is: http://www.batteryuniversity.com/partone-5A.htm :
"
In 1996, scientists succeeded in using lithium manganese oxide as a cathode material. This substance forms a three-dimensional spinel structure that improves the ion flow between the electrodes. High ion flow lowers the internal resistance and increases loading capability. The resistance stays low with cycling, however, the battery does age and the overall service life is similar to that of cobalt. Spinel has an inherently high thermal stability and needs less safety circuitry than a cobalt system.Low internal cell resistance is the key to high rate capability. This characteristic benefits fast-charging and high-current discharging. A spinel-based lithium-ion in an 18650 cell can be discharged at 20-30A with marginal heat build-up. Short one-second load pulses of twice the specified current are permissible. Some heat build-up cannot be prevented and the cell temperature should not exceed 80°C.
"

So LiMn does not age the same way other Lithiums do. They maintain low internal resistance through their life (unless abused). Cool ! I'm still not quite sure how they age; must be lower capacity, even though resistance stays low ?

"Battery University" is a great, informative site. Start here: http://www.batteryuniversity.com/partone.htm and progress to part two when done.

Of course while riding and charging, current is not constant, except perhaps in CC phase and at max throttle. I wonder if fan or speed wind cooling would increase life at high C rates ? (Imagine Homer Simpson adding "speed holes" to batteries. )

IMO, you should be able to charge just as fast as you discharge; the heat physics are the same I think both ways. So in theory, you could charge at 30 amps, but that would probably only be good for 2 minutes or so with discharged pack before you'd go to CV phase with current declining to keep cells at or under 4.2v.

I think I will stick with 12 amps as max charge rate; but I've been considering 6 amps or so to increase life and because it would only increase charge time by maybe 15-20 minutes or so.

Charge and discharge rates in amps or C are the same no matter if you have 1s or 100s. Same current flows through all batts/cells, assuming you have no balancing shunts or whatever. Parallel is different of course; in best case your parallel packs are well matched so current divides equally between each side.

 

[mikereidis]

I'm trying to decipher the part numbers and circuitry of the YW charger.

I'm stuck on 1C1, which is the only 8 pin chip on the bottom/back/solder side of the board. Numbers seem smudged.

Can anyone see what the numbers/letters are on IC1 ? Best I can do is:

28600D
ti 7AM
A2J1

This is from my notes. I look again and bottom line seems to be A1XN.

So I guess ti = Texas Instruments. Bottom number probably date code ? This chip is the last in the output section and is probably real important for current limiting or CC -> CV mode switching.

I need my reading glasses and magnifier to get this far.

Since this chip is on bottom, you'd only have to remove 4 screws from charger; you don't have to remove circuit board.

 

[steveo]

BASICLY IMO

YW charger (crap.. don't waste your time)
YW bms (again Crap don't waste your time, I had nightmares with my dewalt bms, I don't trust anything yardworks is going to include with this $109 battery; Use a 3rd party balancer for god sakes; I think a lipo blinky balancer will do a heck of a better job.

Battery testing to come...

p.s. What would you say is a safe charge rate for these cells? What it the safest discharge rate for these batteries also say for a 20s pack?
Have you found any specs on the batteries? I wish i had the battery info here with me just curious to find some info on the cells themselves.

-steveo

Cool ! Wonderful, I'm looking forward to more feedback and detailed testing results.

Yes, charger and BMS, kinda crappy, but not TOO bad (for the price) as baseline or "training wheels" until we get/build some better ones.

Safe ? I dunno, we're doing our own R&D here. In a post in first 2-3 pages the numbers on batts were deciphered to indicate 6 amp-hours (which we already know), nominal voltage 18.5v (normal for 5 LiMn cells) and max discharge rate of 31 amps (5+ C). I've never hit the BMS current limit but I think someone (NutsAndVolts?) mentioned they cut out around 30 amps or so.

IMO, safest, most life enhancing charge or discharge current for any battery is 0 amps, or just slightly more.

There's a nice graph here: http://www.batteryuniversity.com/parttwo-34.htm that indicates 1c charge/discharge might last 500 cycles with 15% or so drop in capacity. 2c might last 200 cycles with same 15% drop, and 3c perhaps 50 cycles. Maybe LiMn is better, I don't recall right now.

EDIT: Oh, here it is: http://www.batteryuniversity.com/partone-5A.htm :
"
In 1996, scientists succeeded in using lithium manganese oxide as a cathode material. This substance forms a three-dimensional spinel structure that improves the ion flow between the electrodes. High ion flow lowers the internal resistance and increases loading capability. The resistance stays low with cycling, however, the battery does age and the overall service life is similar to that of cobalt. Spinel has an inherently high thermal stability and needs less safety circuitry than a cobalt system.Low internal cell resistance is the key to high rate capability. This characteristic benefits fast-charging and high-current discharging. A spinel-based lithium-ion in an 18650 cell can be discharged at 20-30A with marginal heat build-up. Short one-second load pulses of twice the specified current are permissible. Some heat build-up cannot be prevented and the cell temperature should not exceed 80°C.
"

So LiMn does not age the same way other Lithiums do. They maintain low internal resistance through their life (unless abused). Cool ! I'm still not quite sure how they age; must be lower capacity, even though resistance stays low ?

"Battery University" is a great, informative site. Start here: http://www.batteryuniversity.com/partone.htm and progress to part two when done.

Of course while riding and charging, current is not constant, except perhaps in CC phase and at max throttle. I wonder if fan or speed wind cooling would increase life at high C rates ? (Imagine Homer Simpson adding "speed holes" to batteries. )

IMO, you should be able to charge just as fast as you discharge; the heat physics are the same I think both ways. So in theory, you could charge at 30 amps, but that would probably only be good for 2 minutes or so with discharged pack before you'd go to CV phase with current declining to keep cells at or under 4.2v.

I think I will stick with 12 amps as max charge rate; but I've been considering 6 amps or so to increase life and because it would only increase charge time by maybe 15-20 minutes or so.

Charge and discharge rates in amps or C are the same no matter if you have 1s or 100s. Same current flows through all batts/cells, assuming you have no balancing shunts or whatever. Parallel is different of course; in best case your parallel packs are well matched so current divides equally between each side.

my neighbour got his 4s pack all charged & balanced today;

I took his vespa like electric scooter for a spin with his China Cheapy hub motor & 48v 35 amp controller;

Ran the bike with a 3s pack for starters; 63v of the charger which is good! ... we got it to top out close to 50km/h on a 16" rim ..

we have one more pack to get 84v going for him..

so far all is well .. we took it for a nice hard run .. drained 1ah out of the batteries based on the watts up metter... very please with results so far!! .. i would like to see what his max ah will be! ohh and i would like to see him bury the needle at 65km/h on his scooter .. would be freakin awesome.. lol

he has gone probably from 60lbs of lead (4 12v 12ah) to less then 10 lbs at 63v .. sick upgrade for this scooter!!...

i will keep all posted

-steveo

 

[mikereidis]

my neighbour got his 4s pack all charged & balanced today;

I took his vespa like electric scooter for a spin with his China Cheapy hub motor & 48v 35 amp controller;

Ran the bike with a 3s pack for starters; 63v of the charger which is good! ... we got it to top out close to 50km/h on a 16" rim ..

we have one more pack to get 84v going for him..

so far all is well .. we took it for a nice hard run .. drained 1ah out of the batteries based on the watts up metter... very please with results so far!! .. i would like to see what his max ah will be! ohh and i would like to see him bury the needle at 65km/h on his scooter .. would be freakin awesome.. lol

he has gone probably from 60lbs of lead (4 12v 12ah) to less then 10 lbs at 63v .. sick upgrade for this scooter!!...

i will keep all posted

-steveo

Woohoo ! My 404 on 19.1 inches at 84v, 20a should in theory be capable of 65 KMH on flat when fully charged on new undamaged batteries. Based on ebikes simulator and the defunct German website with power vs speed stats.

I suspect a 48v controller will blow at 80-84v though, unless it's severely under-rated which I doubt. Maybe 60-75v caps on that.

I've had no trouble on my XLyte "24-72v", 20a, pedal first I got for $145 from ebikes.ca . When I bought it was warrantied up to the magic 84v value.


I re-assembled 3 of 4 meltdown incident batts into a 19 cell pack with my spare batt. I got 19+ amps out of it at 78v open circuit; forget the loaded voltage. After a few KMs though the loaded voltage was dipping to 50v range at 5 amps or so. First time I've had all 9 batts on bike, or 8.6 (43 cells), or 8.2 (41 active cells) depending on how you count.

The superbad batt that broke it's compression bands had the two bad cells removed and is now a 12+ volt bike light batt. With bulging about the same size as unbulged 5 cell batt. I added a few wraps of "duct tape compression bands".

Funny that the bad cells are hardly bulged. I almost wonder if bulging helped "save" the other cells. Now I'm wonder exactly what bulging is, and if it has something to do with this spinel structure.

 

[mikereidis]

I've started a charger/BMS build thread here: http://endless-sphere.com/forums/viewtopic.php?f=14&t=6650

I just noticed last night there is a pot on the YW charger to adjust voltage. Range was around 19.6v to 21.9v. I trimmed it to 21.00v, after removing the white goop. The output inductor was "singing" at different frequencies as I trimmed.

Tried a 5 ohm load on the charger output. It tripped the protection relay, so 4 amp output seems impossible unless that relay is bypassed.

I tried tapping the YW charger at the output caps, before the limit controls. Voltage was same as output. I got 3.2 amps there, but voltage was down to 16 volt range. There's a power resistor in input section that MIGHT be modifiable for higher current. But the switching transformer may be a hard limit also.

Parallelling two YW chargers, trimmed to same voltage, at switching caps might yield a 21v supply good for 5 amps or so.

I wonder if feeding 240vac to YW charger might increase capacity. Diode bridge is rated for 400 PIV, but caps might blow. Fets or whatever could easily blow too.

If all else fails, (except the charger) the YW chargers might be OK as DC-DC converters. 120vac -> 150vdc/21vdc is about 80v/11.2v. Might be good for bike lights etc.

 

[mikereidis]

The cells cases are the positive terminal of the cell. That explains why those "spacers" are there; they are insulators. Top "spacer" seems superfluous though, except as a place to put the serial number sticker. So the only place that negative comes out is right at the negative terminal, and there's an insulator there. Negative terminal is the one you need to be careful with, if a DMM probe slips it will spark.

I've been nervous about ways to connect negative terminals when the wires break. So far I've been OK, usually using next cell positive and wrapping/twisting a wire in that direction. End terminals are good for using a slide connector.

Main battery wires are 12 gauge. Voltage sense wires seem to be 18 gauge. A bit small to use for balancing, unless current is on low side.

 

[mikereidis]

My hyper-miling runs, pedalling up hills and keeping speeds to 15-30 KMH range have been nicely efficient. I keep thinking the 4 batt packs are low at end with 22 KMs done, but in two cases with 22 KM rides I only put 2.5 AH back in pack to get back to start voltage (78v with 19 cells). I think it'd work much better with undamaged batts.

I don't see myself going beyond 8 or so YW batts on bike. Beyond that, my range extension solution is on-bike charging. I much prefer a lighter bike with only 4 batts though. Need that velcro solution, but first priority is safe charging, 2nd is new batts (waiting for safe charging before I get new batts).


The $10 on sale ending today Canadian Tire DMM worked very well last night. Didn't blow "10 amp" range. This DMM has plus that 200v range shows tenths of a volt resolution. Also very nice is no auto shutoff ! I hate constantly twisting to off and back to voltage. DMM is a bit smaller than before; has probe holders on side and a strap on back. Probe connectors were a bit loose, but some tape solved that. Wonder how many pounds of tape on my bike.

I'm gonna buy a bunch of these DMMs today, for incorporation into the first batch of "Danger brand chargers". Discounts for ES members of course, and first N customers only pay parts cost, where #1 is NutsAndVolts/Doug, assuming he hasn't been too scared away by my meltdown pics. (Hey, come back Doug, it's an acknowledged weakness of the v1 model...)

 

[mikereidis]

my latest issue is uneven battery lelel's after run...
starting from yw1 20v yw2 20v sla13.60v
after 8km at 45kmh strait no cooling breaks(motor is hot)
ending volts...yw1 16.01v...yw2 18.60v...sla 12.63v
they are wired just as shown and i think the bottom yw bat
is taking the brunt...? i think i will rearange my wires
so sla is bottom bat and see if it takes the hit and my
limn's even out some in discharge? does that make sence?

So 45 KMH and 8 KM indicates a run time of 0.178 hours. Assuming 5 AH (which I think is about right from these batts at higher currents) that could indicate you were pulling 28 amps ? Or more likely 20+ amps or so, and your AH was down in 4 AH vicinity due to whatever.

Does your range increase much with SLA in the pack ? If SLA is small, it could even decrease your range, or add very little.

My earlier comment about 17% more charge left in higher batt means:

- Low pack may have been at 3% of full capacity (IE. 0.18 AH left)
- High pack may have been at 20% of full capacity (IE. 1.2 AH left)

If you or anyone else feels comfortable doing, I highly recommend checking all 5 cell voltages at full charge. Basically, remove 4 screws, carefully but firmly use blade screwdriver on each side to pry cell pack out of case, being careful to keep voltage monitor LEDs board from touching terminals or BMS. Check cells with DMM being careful not to let probe slip on negative terminals. Alternatively you could check voltages on BMS board where sensor wires connect and cell pack can stay in case. Modding the case a bit could bring some added cell sensor wires outside of case to check in future without opening case. Anyway, I don't want this advice to cause anyone to cause any damage unless they are aware of, and accept the risks. But you do risk your cells anyway, just by trusting them to the non-balancing YW BMS, IMO.

IMO these batts, BMSs and charger are designed to make the batts fail (or reduce capacity a lot) after the 1 year warranty expires and before 2 years of life. Can Tire must keep the replacement battery revenue coming to please their stock-holders.


I was at the nice tool and fastener shop yesterday, stocking up on $100 worth of wire, duct and electrical tape, etc. etc. I checked the prices on DeWalt and Milwaukee Lithium. Can Tire YW has those prices beat by a factor of 2-3:1 on a WH basis ! One plus is that YW batts are bigger, WH wise.

 

[wasp]

i fried one of my yw bats today...
brought bike in for work and on the way home
noticed my stock 24v lit throttle lights going out
so i stopped and checked wiring and found the -
off my sla...so rehooked it up and continued...
10 blocks later lights start going low again?
drove home slower to keep lights lit up(even pedaling)
get home check bats...sla 12.71v...yw1 19.36v...yw2
0.368v !!!! now on charger and will check on it
i must have been running on only 1 yw bat!!!
ct here only has 1 more left in stock...warrenty time
still love these bats my bad thats all

 

[steveo]

i fried one of my yw bats today...
brought bike in for work and on the way home
noticed my stock 24v lit throttle lights going out
so i stopped and checked wiring and found the -
off my sla...so rehooked it up and continued...
10 blocks later lights start going low again?
drove home slower to keep lights lit up(even pedaling)
get home check bats...sla 12.71v...yw1 19.36v...yw2
0.368v !!!! now on charger and will check on it
i must have been running on only 1 yw bat!!!
ct here only has 1 more left in stock...warrenty time
still love these bats my bad thats all

buy after market lipo balancer and use a psu as a charger.. get rid of the yw charger/bms if you haven't already.'
if you have a r/c chargers; charge each cell at .05amp to bring the voltages in range.

-steveo

 

[mikereidis]

i fried one of my yw bats today...
brought bike in for work and on the way home
noticed my stock 24v lit throttle lights going out
so i stopped and checked wiring and found the -
off my sla...so rehooked it up and continued...
10 blocks later lights start going low again?
drove home slower to keep lights lit up(even pedaling)
get home check bats...sla 12.71v...yw1 19.36v...yw2
0.368v !!!! now on charger and will check on it
i must have been running on only 1 yw bat!!!
ct here only has 1 more left in stock...warrenty time
still love these bats my bad thats all

In theory, the BMS should be protecting you from shorts or currents over 30a, no ?

Well if it's warranty time, crack that baby open and let us know what the cell voltages are...

I presume they can/will order a new one if they have no stock. Do you get an option to get money back if they have no stock ?

I haven't returned any yet; waiting for better, safer charger before I risk any more virgins. Do they just take it and take your word for it, or do they make you go to the "trimmer guy" for an analysis. If so, 0v and 0 LEDs lit might be a faster way to get through that.

I'm trying to recall, but do they ask for ID when returning ? I'm thinking I'll buy a few with cash, and act all indignant if they ask for ID at return. (Let's see your ID and give me your home address and phone, Mr Manager.)

 

[wasp]

well after 90min on charger it registered 0.103v
can you say cooked...wonder why lvc didn't work?
returned no questions asked...full refund..no bats
in stock so i'm running my 3 12v 12ah sla's...and
THEY SUCK....i hate it
i will never(lol exept now) use sla again...you take
for granted the power of lithium untill you go back
to sla's

 

[drunkencat129]

oke guys i tested my bike last night i burned 4.2ah out of my pack and i did about 11km i got a crazy dangrous pack build in progress lol i got 11ah lipo packs 18 v each pack each cell is made up of 4 cells so its 5s4p so im planing on makeing a 80v monster back for back up so i can do my testing on theas yardworks cells

 

[mikereidis]

PC interface balancing chargers for RC / EBike

http://endless-sphere.com/forums/viewtopic.php?f=14&t=6678

FMA Cellpro 10s charger looks nice.

 

[mikereidis]

buy after market lipo balancer and use a psu as a charger.. get rid of the yw charger/bms if you haven't already.'
if you have a r/c chargers; charge each cell at .05amp to bring the voltages in range.

-steveo

Steveo: do you have any opinions or insight to offer on balancers ?

I was looking at the iCharger 1010B, moved my sights to the FMA Cellpro 10s, but I'm now looking at balancers that can be used without a charger, or with my own charge/discharge equipment, like the TME Xtrema.

The TME Xtrema has an I^2-C interface and information is supposed to be available on their protocol. With 4 balancers and 2 BIMs it can handle up to 6x4 cells or 24s. Would work well for my 84v max, 20s setup. The FMA cellpro is good for 10s max so I'd have some fiddling of some sort to do with my packs.

I could and perhaps will build a balancer of my own at some point, but it takes time etc. and I'd rather have a safe charging solution sooner with a purchased product. And if I can get PC interface with all cell voltages at all times (charge, discharge, rest) at least that seals the deal. Nice to have would be PC initiate-able and controllable balancing, discharge testing, current monitoring for charge and test or biking discharge.

A good balancer would allow me to keep using my high current, dangerous charger in a much safer manner. A big, heavy 12v PSU on my bike, which is needed by most chargers, is not ideal, although I could use a lower amp supply on the bike than at home.

I want a "balancer and cell voltage monitor" that can be left on the bike at all times, so smallish size, low weight and the electrical ability to do that with minimal if any current draw from batts are important.

One thing I liked about the FMA Cellpro 10s is the ability to balance at up to 4 amps, which works better with damaged cells. The iCharger 1010 only went to 400 ma or so, and the TME Xtrema is about the same. I presume the Cellpro must use 10 power resistors that can dissipate 15-20 watts of heat each. If they or similar could be used for up to 4 amp load testing, that would be nice.

I'm hoping that I'll get a new batch of virgin YW batts and their internal resistances will be close enough that almost no balancing will be needed. And I'll be looking to use conservative values for charge current and voltage, LVC, and will parallel my two YW 20s1p packs for longer batt life. I'm thinking I'll stick with the stock 20 amp limit on my controller because, except for fast fun, I don't need more than 20a at 80v. My priorities are range and batt life so I'm keeping my amps down.

For a computer interface, I'm more concerned about being able to write my own Linux code than what the usually Windows only software usually provides. So an open, documented interface/protocol is useful to me; although I could reverse-engineer the thing, I'd prefer to not have to do so, and to do business with a company that makes it easy. Open source availability would be a big plus too. AFAICT all PC interface chargers seem to use a serial port on USB, but I'm just looking at balancers now and they may have "trickier" interfaces like I^2-C or pseudo I^2-C.

 

[steveo]

buy after market lipo balancer and use a psu as a charger.. get rid of the yw charger/bms if you haven't already.'
if you have a r/c chargers; charge each cell at .05amp to bring the voltages in range.

-steveo

Steveo: do you have any opinions or insight to offer on balancers ?

I was looking at the iCharger 1010B, moved my sights to the FMA Cellpro 10s, but I'm now looking at balancers that can be used without a charger, or with my own charge/discharge equipment, like the TME Xtrema.

The TME Xtrema has an I^2-C interface and information is supposed to be available on their protocol. With 4 balancers and 2 BIMs it can handle up to 6x4 cells or 24s. Would work well for my 84v max, 20s setup. The FMA cellpro is good for 10s max so I'd have some fiddling of some sort to do with my packs.

I could and perhaps will build a balancer of my own at some point, but it takes time etc. and I'd rather have a safe charging solution sooner with a purchased product. And if I can get PC interface with all cell voltages at all times (charge, discharge, rest) at least that seals the deal. Nice to have would be PC initiate-able and controllable balancing, discharge testing, current monitoring for charge and test or biking discharge.

A good balancer would allow me to keep using my high current, dangerous charger in a much safer manner. A big, heavy 12v PSU on my bike, which is needed by most chargers, is not ideal, although I could use a lower amp supply on the bike than at home.

I want a "balancer and cell voltage monitor" that can be left on the bike at all times, so smallish size, low weight and the electrical ability to do that with minimal if any current draw from batts are important.

One thing I liked about the FMA Cellpro 10s is the ability to balance at up to 4 amps, which works better with damaged cells. The iCharger 1010 only went to 400 ma or so, and the TME Xtrema is about the same. I presume the Cellpro must use 10 power resistors that can dissipate 15-20 watts of heat each. If they or similar could be used for up to 4 amp load testing, that would be nice.

I'm hoping that I'll get a new batch of virgin YW batts and their internal resistances will be close enough that almost no balancing will be needed. And I'll be looking to use conservative values for charge current and voltage, LVC, and will parallel my two YW 20s1p packs for longer batt life. I'm thinking I'll stick with the stock 20 amp limit on my controller because, except for fast fun, I don't need more than 20a at 80v. My priorities are range and batt life so I'm keeping my amps down.

For a computer interface, I'm more concerned about being able to write my own Linux code than what the usually Windows only software usually provides. So an open, documented interface/protocol is useful to me; although I could reverse-engineer the thing, I'd prefer to not have to do so, and to do business with a company that makes it easy. Open source availability would be a big plus too. AFAICT all PC interface chargers seem to use a serial port on USB, but I'm just looking at balancers now and they may have "trickier" interfaces like I^2-C or pseudo I^2-C.

Hey

I agree with your views on a balancer that can discharge at a higher amperage then others. I'm letting my neighbor use my sr960 mega power 12s balancer. This one came with my charger. Best time to balance is when charging IMO. There is a mode to let it balance batteries only without charger or with it on the charger.

My neighbor ran his 20s pack today and its pretty quick . 50-60km/h on his 20" inch china motor is awesome!

i'd say try the lipo blinky balancer would work on these packs great!. to bad i have 2 a123 ones .. if there where lipo ones i'd give it to my neighbor to test with on his packs, And they are drain minimal energy in my opinion!.. you could keep them on when charging to or all the time when riding or charging! .. they are like $25 each on ebay.. they do 6s each.

-steveo

 

[drunkencat129]

woot ran 80v today on my e-one scooter and it flys lol mode one dose like 40km at 14 amps and mode 2 does 25 amps at 56 km and mode 3 i chouldent get to it because if i did i whould blow the 3 speed controller im runing the fets are not able to support the amps i got to get some 4110s in it b4 i run it for now ill do my range testing so far it did 9km and i only burned 3.4ah not to bad i got my crazy lipo setup for a temp pack till i get 4 more yw cells so far i almost fryed my soldering gun by mistakingly shorting the tab with the gun at 80v 11ah wow what a flash lol i almost shit my self lol i was like o $@^%~ lol thank god its still usable lol now i got a ballencer problem got to make ballence leads for the lipo pack or if posible some type of bms the packs came with them but i got no idea how to hook them up thay get hot when i do lol so looks like im going to half to charge one at a time

 

[mikereidis]

I'm now seriously considering the TME (Tejera Microsystems Engineering) Xtrema Balancer: http://www.tmenet.com/Xtrema_balancer.htm

Further info on my thread here: http://endless-sphere.com/forums/viewtopic.php?f=14&t=6678&p=101173#p101173

At $35 US for each balancer handling up to 6 cells, this seems like an inexpensive solution for PC interface cell monitoring alone, never mind the balancing, test, etc. features. There are additional costs for BIMs and at least one USB adapter, but I may soon be looking for an inexpensive micro-controller with 4 or more opto-isolated I2C interfaces to avoid the BIMs etc, and to provide whatever features I need/want without requiring a laptop full time on my bike.

 

[mikereidis]

Man ! Every time I bypass damaged cells on my 4 YW pack, the bike feels like new again. Much better range, power, and voltage drops imply a good 25 milli-ohm internal resistance per cell at 20 amps again.

I was down to 19 cells previously on my best pack, but now I'm down to 17 good ones. 17 good ones feels MUCH better than 17 good plus 2 bad. One newly bad one was about 0v (a top cell), but the other was up and down (a bottom cell).

Funny, except for my massive overcharge meltdown, which killed a center cell and the one on top of it, all bad cells have been bottom or top. In the meltdown the completely failed middle cells were hardly bulged, but the others, which were much more alive (but still very damaged of course) were ballooned to twice normal size.


I'm REALLY looking forward to getting a decent balancing and cell monitoring solution together, getting new virgin batts, and getting more range and power (YW BMS-less) than I've had to date.

 

[wasp]

here's a link to some battery boxes(pretty sweet) but check out the batteries...
http://www.ampedbikes.com/forum/viewtopic.php?f=5&t=51

 

[mikereidis]

here's a link to some battery boxes(pretty sweet) but check out the batteries...
http://www.ampedbikes.com/forum/viewtopic.php?f=5&t=51

UmmKay...

I wonder what YW battery stock looks like at the CTire warehouse or the bigger Toronto stores. I get concerned we ebikers etc. could run down the stock, esp. over winter when not too much trimming goes on.

Anyone know where we could buy a truckload of these cells for $10 each; half the retail price ? That'd be $0.50 per WH, and even the $1.00 per WH figure is compelling for these LiMn. I think many Americans would snap these up at the prices we are paying. Maybe I should contact the manufacturer...


My micro-controller based charger/BMS/uber-bike-computer project is now under way in earnest. I'm using the basic "dangerous" charger I built, and will use micro-controller and some added components to make it a safer, better, faster charger/BMS/etc with as much PC logging/graphing etc features as I (or other GPL contributors) can add.

More here: http://endless-sphere.com/forums/viewtopic.php?f=14&t=6678&p=101556#p101556 here: http://tmenet.com/forums/index.php?topic=293.0 and here: http://www.rcgroups.com/forums/showthread.php?t=930698#post10648655

 

[29a]

couldn't find any left in the stores in Toronto !
So I got them online http://www.canadiantire.ca/browse/category_landing.jsp
put this in the search field on that page 20V lithium battery
They only took 2 day's to get to me.
I'm thinking of running 60V 12AH
Any of you guy's got an of the shelf suggestion for charging balancing

 

[mikereidis]

couldn't find any left in the stores in Toronto !
So I got them online http://www.canadiantire.ca/browse/category_landing.jsp
put this in the search field on that page 20V lithium battery
They only took 2 day's to get to me.
I'm thinking of running 60V 12AH
Any of you guy's got an of the shelf suggestion for charging balancing

OMG !!

Maybe they running out of stock as winter approaches as I feared ! Better get my order in soon, online ordering may be easier than running around to multiple stores.

EDIT: 5 more ordered, 23.99 for express shipping; guess I got bit by Quebec PST since they use my shipping address, unlike when I pick up in Ontario stores.
So that'll be 5 virgin batts and 9 damaged ones...

Virgin batts will be watched REAL closely on the TME balancers I should be getting in next few days, AFTER I get any bugs worked out testing the balancers with damaged batts.

For balancers:

Cheapo blinkies or whatever should work.

I've ordered 4 TME balancers and 2 BIMs so I can monitor/log all cell voltages in real time. See my thread: http://endless-sphere.com/forums/viewtopic.php?f=14&t=6678

 

[pwbset]

So that'll be 5 virgin batts and 9 damaged ones...

And over $1,400 that could been used to buy a lot of PSI or a123. :wink: Tinkering is definitely an expensive hobby!