My XM-5000li Experience

227 posts / 0 new
Last post
zarlor
Offline
Last seen: 13 years 4 months ago
Joined: Thursday, July 3, 2008 - 07:02
Points: 146
Re: Electric Scooter/Motorcycle Design Change

I can't say that I have much in the way of hills here, other than bridges and inclines leading up to the levees, but there is a bit of an incline at a red light that I was on today that made me think of this thread. (I'd never really thought about it all before, to be honest.) While I'd agree that there really is no lag time getting on the throttle, I'm not sure that it really matters all that much. Yeah, at 275lbs for an XM-3500-Li (plus my laptop and just general gear), it's not a lightweight, but it's just not that hard to hold the bike in place with one foot on the ground, it seems to me. So even if there was a delay it probably wouldn't be long enough to cause you much worry about rolling back, i wouldn't think.

Lenny Zimmermann
Metairie, LA

chas_stevenson
chas_stevenson's picture
Offline
Last seen: 12 years 6 months ago
Joined: Wednesday, December 6, 2006 - 17:14
Points: 1309
Re: Electric Scooter/Motorcycle Design Change

I think the only worry about rolling back is on an ICE bike because you have to operate the throttle, clutch, and brake all together to get going on an incline. This is not an issue with an electric bike as you all have noted the delay from releasing the brake to the throttle on is imperceptible. Just one more advantage to going green with electric.

Just a thought,
Grandpa Chas S.

garygid
Offline
Last seen: 13 years 6 months ago
Joined: Friday, December 19, 2008 - 23:25
Points: 441
Re: Parts Sources

R: I will order the 24-pin (and other sizes as well) VAL-U-LOK connectors from Mouser (www.mouser.com).

M: Where did you get the 12-position, 2-pole rotary switches?
The least expensive that I have found are about $17 each.

Any good source for an inexpensive 0-5v DC analog voltmeter?

Thanks, Gary

Cheers, Gary
XM-5000Li, wired for cell voltage measuring and logging.

Iccarus
Iccarus's picture
Offline
Last seen: 6 years 9 months ago
Joined: Saturday, December 20, 2008 - 08:05
Points: 347
Re: Parts Sources

I agree Grandpa, also if you downshift to economy mode it makes it easier to make a smooth start. I like to stay in economy mode in tight places as it is possible to slip and twist the throttle a little to much and these bike do have considerable pickup. At least with 24cells and that solder wicking mod. I've scared myself a couple times and I have pretty much experience. But once you get alot of experience you may never use economy mode. Personal preference I guess.

2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS

KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl

Iccarus
Iccarus's picture
Offline
Last seen: 6 years 9 months ago
Joined: Saturday, December 20, 2008 - 08:05
Points: 347
Re: Parts Sources

Would it be possible to use thin enough gage wires for the BMS that if they shorted they would just melt and lose contact before doing any damage, after all they don't have to handle much current. Alot easier than fusing all cells. I know this may be seem stupid but I was just wondering. Also I wondered if anyone had any ideas on those balance/monitor cards from commonsense rc. They only discharge cells at 150mah but they will balance the cells but it can take days to work completely. Could you solder higher capacity resisters to them? Or am I just wasting my time?

2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS

KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl

PJD
PJD's picture
Offline
Last seen: 1 week 4 days ago
Joined: Wednesday, November 22, 2006 - 05:44
Points: 1416
Re: Manual Cell-Condition Checking

You should also consider to limit the potential current flow to prevent electrocution. 50mA is plenty to kill a human, and the 60V battery can deliver this.

Unless the 60 volts is applied through electrodes piercing the skin on each arm or deliberate measures made to increase the conductivity of skin, 60 volts is unlikely to produce enough current to electrocute anyone. Remember you have to close the circuit between the poles of the pack, not just be earth-grounded like AC.

But, some energized parts could have sharp edges that could pierce your skin. So it is a good idea to avoid contact with both poles of the pack at once.

PJD
PJD's picture
Offline
Last seen: 1 week 4 days ago
Joined: Wednesday, November 22, 2006 - 05:44
Points: 1416
Re: Manual Cell-Condition Checking

Gary,

If there is indeed a lag between the release of the brake and power to the motor, this is a problem. But you may just need to get accustomized to the controls. I have to start on steep slopes all the time, and I initially found it bit awkward. But in the case of the e-max the lag is either very short or I've so attuned to it that I start up smoothly every time.

If you do have to defeat the brake lockout feature, it is easy to do. Most scooter controllers just use the +12 volts from the brake tail light circuit as the brake shutoff signal, so simply find the signal wire to the controller that gets energized to +12 volts (relative to pack negative) when a brake lever is squeezed, and disconnect this wire. Of course, don't cut any wires from the brake levers or your brake tail light won't work.

I would hope that X-treme has wiring diagrams for this scooter - that would make finding the signal wire easier yet.

Mik
Mik's picture
Offline
Last seen: 8 years 1 week ago
Joined: Tuesday, December 11, 2007 - 15:27
Points: 3739
Re: Parts Sources

R: I will order the 24-pin (and other sizes as well) VAL-U-LOK connectors from Mouser (www.mouser.com).

M: Where did you get the 12-position, 2-pole rotary switches?
The least expensive that I have found are about $17 each.

Any good source for an inexpensive 0-5v DC analog voltmeter?

Thanks, Gary

All switches are from either Jaycar or Dick Smith electronics shops.

But there is no 12 position 2 pole switch in there.

There is one 12 position, single ple switch, all the others are 6 position, 2 pole switches.

They cost around AU$ 4.- a piece.

This information may be used entirely at your own risk.

There is always a way if there is no other way!

Mik
Mik's picture
Offline
Last seen: 8 years 1 week ago
Joined: Tuesday, December 11, 2007 - 15:27
Points: 3739
Re: Manual Cell-Condition Checking
You should also consider to limit the potential current flow to prevent electrocution. 50mA is plenty to kill a human, and the 60V battery can deliver this.

Unless the 60 volts is applied through electrodes piercing the skin on each arm or deliberate measures made to increase the conductivity of skin, 60 volts is unlikely to produce enough current to electrocute anyone. Remember you have to close the circuit between the poles of the pack, not just be earth-grounded like AC.

But, some energized parts could have sharp edges that could pierce your skin. So it is a good idea to avoid contact with both poles of the pack at once.

You are correct.

But for safety reasons I always try to assume the worst (well, almost worst) case scenario:

Lying in a saltwater puddle, caught under the weight of the bike, with multiple abrasions and injuries, and potentially in contact with the mangled remains of whatever gizmo was attached to the bike at the time of the accident.

Or, a rescue worker grabbing stuff with both (wet) hands, unaware of the existence of electric vehicles! S/he'll have a rude awakening...

Apart from that, try to solder this stuff, or repair the popped rotary switch, if the full current flows each time you make a mistake: ;-)
//i281.photobucket.com/albums/kk217/Mr_Mik/Vectux/Battery/Battery%20rework%205%20BMS/th_DSC06164.jpg) //i281.photobucket.com/albums/kk217/Mr_Mik/Vectux/Battery/Battery%20rework%205%20BMS/th_DSC06157.jpg) //i281.photobucket.com/albums/kk217/Mr_Mik/Vectux/Battery/Battery%20rework%205%20BMS/th_DSC06127.jpg) //i281.photobucket.com/albums/kk217/Mr_Mik/Vectux/Battery/Battery%20rework%205%20BMS/th_DSC06108.jpg)

This information may be used entirely at your own risk.

There is always a way if there is no other way!

PJD
PJD's picture
Offline
Last seen: 1 week 4 days ago
Joined: Wednesday, November 22, 2006 - 05:44
Points: 1416
Re: Manual Cell-Condition Checking

MIK's rotary switch and voltmeter is slick and convenient, but another simpler approach is to just wire the pack negative and each positive cell terminal to a multi pin connector (of the type where each pin is in it's own socket so shorting while checking isn't possible). Each cell's voltage is then just checked with the probes of a voltmeter.

One such connector is here:
http://www.mouser.com/Search/ProductDetail.aspx?qs=PBcRNPEHKsoNLAu6QmxyFw%3d%3d

This is, of course, the same wiring and connectors you will use for a BMS such as this one: http://www.tppacks.com/products.asp?cat=26

garygid
Offline
Last seen: 13 years 6 months ago
Joined: Friday, December 19, 2008 - 23:25
Points: 441
Re: Manual Cell-Condition Checking

CAUTION:
It appears that the ThunderSky batteries can be (and have been) delivered significantly out of balance.

Thus, it appears that it is possible for the supplied TS charger to substantially over-charge (and then damage) the high cells while attempting to charge up the low cells.

Perhaps it is "safe" to continue to (over) charge the TS cells (at a very low average rate) for days, but, if so, that information has not been made public.

For now, I must assume that using the supplied TS charger (without some form of Battery-cell Limiting or Equilizing System) can damage the "high" cells.

Of course, you might not discover it until many charges later, when reduced range (or power) is encountered.

Although adding a full-on BMS would appear to void X-Treme's battery warranty, a BMS appears to be "required" by the TS battery cell instructions that come with the 5000Li.

So, what to do?

Cheers, Gary
XM-5000Li, wired for cell voltage measuring and logging.

antiscab
Offline
Last seen: 10 months 1 day ago
Joined: Saturday, July 7, 2007 - 23:55
Points: 1686
Re: Manual Cell-Condition Checking

you could add a BMS and just not tell extreme?

Matt

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km

Mik
Mik's picture
Offline
Last seen: 8 years 1 week ago
Joined: Tuesday, December 11, 2007 - 15:27
Points: 3739
Re: Manual Cell-Condition Checking

CAUTION:
It appears that the ThunderSky batteries can be (and have been) delivered significantly out of balance.

....................

So, what to do?

You could charge each cell to full individually just once to get started. Building a BMS will take some time.

This information may be used entirely at your own risk.

There is always a way if there is no other way!

Iccarus
Iccarus's picture
Offline
Last seen: 6 years 9 months ago
Joined: Saturday, December 20, 2008 - 08:05
Points: 347
Re: Manual Cell-Condition Checking

you could also simply put a load on the high cells till you get them where you want them then charge the whole pack.Thanks PJD that bms board is just what I need to make my homemade BMS/monitor work better. You could also buy cell spy cards from commonsence rc and wire them in and mount them up by the dash where you can see them. Each card cycles through a digital readout of up to six cells. so then you can monitor all cells on the fly. One problem though is when the cells get to below 3v the cards turn off. so you can't monitor below 3v. But this works like an early warning for me as I'm running 24 cells and the LVC in the controller will let me drain my batteries to low if I keep going till the controller cuts off. The good thing is I can see what the cells are doing under load while driving.

2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS

KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl

Johnny J
Johnny J's picture
Offline
Last seen: 2 years 8 months ago
Joined: Tuesday, July 8, 2008 - 17:02
Points: 377
Re: Manual Cell-Condition Checking

CAUTION:
It appears that the ThunderSky batteries can be (and have been) delivered significantly out of balance.

Thus, it appears that it is possible for the supplied TS charger to substantially over-charge (and then damage) the high cells while attempting to charge up the low cells.

Perhaps it is "safe" to continue to (over) charge the TS cells (at a very low average rate) for days, but, if so, that information has not been made public.

For now, I must assume that using the supplied TS charger (without some form of Battery-cell Limiting or Equilizing System) can damage the "high" cells.

Of course, you might not discover it until many charges later, when reduced range (or power) is encountered.

Although adding a full-on BMS would appear to void X-Treme's battery warranty, a BMS appears to be "required" by the TS battery cell instructions that come with the 5000Li.

So, what to do?

TS cells should not be significantly out of balance when delivered new.
They should also self balance to some degree when charging.
If a cell or two differ very much, there might be problems with these.

Iccarus
Iccarus's picture
Offline
Last seen: 6 years 9 months ago
Joined: Saturday, December 20, 2008 - 08:05
Points: 347
Re: Manual Cell-Condition Checking

In my experience the only time the cells are more than about .07v apart is right after charging. Then some will be 3.40 while a few may be slightly over 4.20 Particularly if you let the charger go on a few more times after the light turns green. If after a mile run at high speed if they aren't back in line I would say thats unusual, because that seems to get them real close for some reason. I read here somewhere that that's a surface charge that burns off quickly under load. How far apart are they? It's probably not a big deal. I think they should be within .1v

2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS

KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl

PJD
PJD's picture
Offline
Last seen: 1 week 4 days ago
Joined: Wednesday, November 22, 2006 - 05:44
Points: 1416
Re: Manual Cell-Condition Checking

My experience from converting two scooters to Thundersky cells is that they do come at significantly different states of charge from the factory. They need to be individually charged the the same end-of charge voltage before assembling than into a pack and bulk-charging them for the first time. I doubt they do this at the factory making this scooter.

I suspect that if you have a end-of charge voltage difference of 3.40 to 4.20 volts, that does represent a significant imbalance - at least 10%. I remain of the opinion that the cell life may be hurt by repeated charging over about 3.8 volts. The open circuit voltage will be about 3.3 volts for a very wide range in the state of charge, so that is not a good indication of the cell's balance.

Iccarus
Iccarus's picture
Offline
Last seen: 6 years 9 months ago
Joined: Saturday, December 20, 2008 - 08:05
Points: 347
Re: Manual Cell-Condition Checking

What do you use to individually charge your cells? I've wanted to do this before but couldn't get any of my hobby lipo chargers to work. Also what do you mean by open circuit voltage. Do you mean it's best to check them under load?

2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS

KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl

Iccarus
Iccarus's picture
Offline
Last seen: 6 years 9 months ago
Joined: Saturday, December 20, 2008 - 08:05
Points: 347
Re: Manual Cell-Condition Checking

When I added my 4 cells I just ran the pack down to the same voltage the new batteries came to me at. Then installed the batteries and charged them with the new charger. The 4 cells were balanced and in a 4 pack strapped in together already. I hope this was ok, they are staying in balance with the rest of the pack. Maybe we are all suffering from battery overprotectionitis.

2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS

KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl

antiscab
Offline
Last seen: 10 months 1 day ago
Joined: Saturday, July 7, 2007 - 23:55
Points: 1686
Re: Manual Cell-Condition Checking

voltage under load does vary quite a bit and increases with load (for my pack ~0.1vpc at 50A, ~0.2vpc at 100A, though that might be just the resolution on my paktrakr being a little too low).

voltage at no load is meaningless.

PJD is right, batteries as delivered are all over the place with respect to SOC.

i bench tested a cell some time ago with a CBAII battery analyzer.
the difference i found between charging to 3.4v and 4.2v (while letting curent fall to 0.03A) was 1AH
i cant find the graph the program made, but i can repeat the test soon (just need to get my lab power supply back from the workshop).
There might be some other side effect of lower end of charge voltage, but that was the immediate effect.

Matt

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km

Iccarus
Iccarus's picture
Offline
Last seen: 6 years 9 months ago
Joined: Saturday, December 20, 2008 - 08:05
Points: 347
Re: Manual Cell-Condition Checking

Don't you mean the voltage decreases with load? On mine if I increase throttle the voltage drops if I back off it comes back up. Really, voltage at no load is meaningless? That doesn't tell you anything about SOC? How much load does it take to get an accurate reading? My new cells were at between 3.20 and 3.23 when I got them. I just drove the bike till my stock pack read in that range at rest. Then installed the 4 extra cells. They all track fine except when pushing a charge. At least thats what I've observed so far. I probably need to get a life!

Bill

2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS

KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl

garygid
Offline
Last seen: 13 years 6 months ago
Joined: Friday, December 19, 2008 - 23:25
Points: 441
Re: ThunderSky Charger for 5000Li

The TS charger supplied with the XM-5000Li appears to work in four Phases. We assume that the Phase selected is based on the charger's measurement of the Pack's "resting" voltage. Currently, we do not know V1, V2, or V3.

Phase 1: High Current Charging (roughly 15 amps, or a bit less). This phase seems to "pause" for a minute or two at about 20 minute intervals. During this pause, the Pack's cells can "relax" and then the "resting" voltage can be measured. While charging is actually in progress, the cell voltage is artificially high. (Likewise, during discharge, the cell's voltage is artificially low.) When the resting voltage gets over V1, then it would seem that Phase 1 is over and Phase 2 begins.

Phase 2: Gradually reducing the Charge Current (down to about 2 amps). As the voltage climbs from V1 to V2, the charging current is reduced. This might happen in something like 15 minutes or an hour or so. The time might depend upon how many cells are "low". Apparently at some V2, the charger enters a much longer Phase 3.

Phase 3: Low Rate Charging (about 0.2 amps average) until V3 is reached. During this Phase, the charger "pauses" (essentially zero charging amps) for about 20 minutes, and then it charges at about 2 amps for about 2 minutes.
Note: This is sometimes referred to as "pulse" charging.

So, this one-tenth duty cycle of about 2 amps is essentially an average charge rate of 0.2 amps. During this time, any "high" cells will continue to (over)charge and potentially damage these cells while the "low" cells are being charged up to near "full". This Phase can last for a long time, even many days when the cells are significantly out-of-balance (as was found at delivery).

Phase 4: The Charger turns itself OFF, presumably when the Pack reaches V3. So far, in several days of charging, this Phase has not yet been observed. But, presumably it exists.

The Problem:
It appears that this TS charger, used alone, has a good possibility of damaging the Pack's cells unless all the cells are well balanced. Some cells were observed to be substantially out of balance at delivery.

Or, perhaps TS knows that the Phase 3 low-rate over-charge is not harmful to a "full" cell. If TS does know this, then it has not yet been made public as far as I know. The TS battery manual states that a BMS is "required" when using these cells (presumably, if one wants to achieve long life and good service from the cells).

If a suitable BMS is used to limit this overcharging of the "high" cells, then the Phase 3 will gradually charge the "low" cells and not over-charge the "high" cells.

The BMS could be a simple voltage-controlled shunt circuit. Note: The "shunt" current must bypass more than 0.2 amps. Shunting only 0.125 amps will not work. Shunting 0.25 amps is perhaps marginal, but shunting 0.5 amps appears to work well to keep the "high" cells from over-charging.

Also Note: X-Treme says that using a BMS will void the Battery Warranty. That puts users in an awkward situation.

Cheers, Gary
XM-5000Li, wired for cell voltage measuring and logging.

garygid
Offline
Last seen: 13 years 6 months ago
Joined: Friday, December 19, 2008 - 23:25
Points: 441
Permission to Check Battery Voltage

In the 5000Li, 6 "top-level" cells sit on top of 6 other "bottom-level" cells, and accessing all the 21 cells, just to measure their voltage, requires substantial disassembly of the scooter, and removal of at least the top-level six cells from the scooter (to access the six cells below).

Just this operation alone might void the X-Treme battery warranty.

However, I am considering the following action that might make it "legal" to perform at least the voltage measurements:

Fill out an X-Treme "Ticket" on-line expressing that you feel that your batteries might be "weak", bad, or out-of-balance, and give your good reasons.

Presumably, they will tell you that it is necessary for you to measure the battery voltages under certain conditions.

Has anybody filed such a "Ticket"?
What was X-Treme's response on the subject?

Assuming they want you to measure voltages, you might respond to them with something like:

"You want me to measure the voltages, but it is necessary for me to take the scooter apart and remove the upper six cells in order to take just one set of voltage measurements. Is it OK for me to connect a wire to each cell just so that I can do the measurements after the battery pack is re-assembled?"

To get several measurements under different conditions of load (or while or after charging) is virtually impossible unless you are allowed to add (VERY CAREFULLY) wires to each cell and re-assemble the scooter. I would suggest, if it does not void your warranty, wiring each cell through a fuse, and connecting all 21 cells, and the pack negative (22 wires), in order of increasing voltage, to a good connector so that there are no loose "ends" of wires to accidentally short. Again, use GREAT CAUTION if you do this. Complete all the wiring FIRST, BEFORE connecting anything to the battery. GET HELP if you are not competent to do this job.

If I get permission, I am intend to use the Val-U-Lok 24-pin (and smaller sizes where needed) connectors (from www.mouser.com).

CAREFULLY using the pins in the connector and a small voltmeter, you could measure the cells before and after charging, after a ride, etc.

Try to get permission to do this voltage-monitoring without voiding your warranty. Be clear that this wiring is not intended for attaching an automatic BMS circuit, that you are not changing any of the existing battery wiring, and that you are charging with the TS charger that came with the scooter.

In a next post, I will try to indicate how one might get significant measurements. Normally, at rest, or even under very light load or charge, cells that are 20% (or even 40%) apart in their State of Charge (SOC) will exhibit very little difference in their voltages. So, even when reading all the voltages as essentially the same, that does not indicate that all the cells are at nearly the same state of charge.

Later, Gary

Cheers, Gary
XM-5000Li, wired for cell voltage measuring and logging.

AndyH
Offline
Last seen: 14 years 5 months ago
Joined: Wednesday, June 4, 2008 - 16:13
Points: 125
Why to Check Re: Permission to Check Battery Voltage

Gary,

I did TWO charges on my bike before my first 3-mile ride. Here's a picture of the pack under load (The voltages are reported time 100 - 270 = 2.70):

21_cells_loaded.jpg

The deep discharge points are at 'wide open throttle' and drawing 90-100A. Notice how the cells that were in the middle of the charge area were the ones that sagged the deepest under load? Resting voltage doesn't tell the whole story.

I found that about 1/2 of my pack was fairly well charged, and that half was somewhere in mid-charge.

The TS charger will eventually bring the low cells up, but you'll have to keep the bike on the charger for multiple days at least.

I've used single and multiple VoltPhreaks 2A LiFePO4 chargers to bring the low cells up. It's faster than the TS charger, and won't push the 'full' cells into the 4-4.3V range.

The Voltphreaks chargers are $9.95 in lots of 10, and $12.95 each for 9 or fewer.
//s.p10.hostingprod.com/ [at] www.voltphreaks.com/ssl/catalog/product_info.php?cPath=3&products_id=60">https://s.p10.hostingprod.com/ [at] www.voltphreaks.com/ssl/catalog/product_info.php?cPath=3&products_id=60

Give the chargers a bit of airspace when charging - they'll get hot. I put them next to each other in a powerstrip and cooked a charger. (I'm not connected to these folks.)

Here's a look at 8 cells in my pack as the TS charger is chugging away. I have a Goodrum/Fechter BMS on and it's keeping the 'full' cells from filling higher than 3.8V, then pulling them back down to 3.7 after the charger stops pulsing. This is 8 hours of data in the chart - each pulse is 2 minutes long; they're spaced 20 minutes apart. The two cells still low have been there thru a full 36 hours of charging. I charged this pack TWICE until the TS charger shut-down -- no - the cells are not charged yet when the charger quits - leave it on and let it work.

2nd_overnight_RemB.jpg

Andy

(BMS? Wiring? I have no recollection of that, Senator!)

antiscab
Offline
Last seen: 10 months 1 day ago
Joined: Saturday, July 7, 2007 - 23:55
Points: 1686
Re: Manual Cell-Condition Checking

Bill,

the voltage decreases with load yes.
but the variance between the cells *increases*.

so one cell at 3.1v and another at 3v would become 3v and 2.8v at twice the load.

voltage at no load is meaningless, because it varies with far to many factors (and the SOC factor is drowned out by the white noise of the other factors).
it is only interesting at either high SOC or low SOC.

if you want to start off with a balanced pack, first charge *all* cells independantly to 4v (the charge to voltage doesnt have to be precise, just between 3.4v and 4.2v) until charge current falls below 0.1A.
i use a lab power supply to do this.

I think you already have a life (its just full of EVs :D )

Matt

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km

Iccarus
Iccarus's picture
Offline
Last seen: 6 years 9 months ago
Joined: Saturday, December 20, 2008 - 08:05
Points: 347
Re: Manual Cell-Condition Checking

Thanks, Gary Matt & Andy the plot thickens. I didn't know I was going to have to become an EE when I bought my 3500li! I'm not complaining though...I'm learning and that's a good thing. Be careful getting readings with the voltmeter off those pins if you do this. I tried doing this to test the accuracy of the balance/monitor cards I installed and shorted two pins together with a voltmeter probe. This caused the wires to heat up enough to melt the shielding on the wires and then the wires shorted. Luckily it was the thin wires that come off the 7pin plugs that the cards plug into and not the heavier running wire I spliced in to go the rest of the distance to the batteries. The thinner wire acted as kind of a fuse and saved the cells that shorted briefly. Thats why I think thats a good precaution to fuse your BMS(oops I mean manual cell checking) leads like gary said. Also by all means be careful swinging wrenches in the battery compartment. It took me about an hour to attach leads to all my batteries. If you fuse the cell leads, I don't see much point unless you place the fuse at the battery though(which will make them hard to get to on the 5000). If you wire them carfully I doubt they will ever short. My cards only shunt 150ma of current so they are to slow to do any good when charging. But overnight they do bring all those high cells down without drawing anything from the lower cells so they are doing somthing at least. If I switch to that unit PJD posted will that do the job?

2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS

KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl

Iccarus
Iccarus's picture
Offline
Last seen: 6 years 9 months ago
Joined: Saturday, December 20, 2008 - 08:05
Points: 347
Re: Manual Cell-Condition Checking

Well I ordered one of those 4-24 cell BMS units from tppacks.com. They only bypass 1amp of current though is that enough? I hope so. Since I'm all wired for it and it's $49 I guess I'll try it. Is anyone using one now...or is that TOP SECRET! Keep the info coming guys, thanks much. And by the way you guy's crack me up, I can hear it now..."Oh THOSE wires well yes they're for manual cell-condition checking yeah yeah thats the ticket manual cell checking. A BMS oh heavens no lol!

Bill

2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS

KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl

Iccarus
Iccarus's picture
Offline
Last seen: 6 years 9 months ago
Joined: Saturday, December 20, 2008 - 08:05
Points: 347
Re: Manual Cell-Condition Checking

Battman, I agree I was wondering the same thing. Maybe it's not good news?

2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS

KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl

AndyH
Offline
Last seen: 14 years 5 months ago
Joined: Wednesday, June 4, 2008 - 16:13
Points: 125
Re: Manual Cell-Condition Checking

Well I ordered one of those 4-24 cell BMS units from tppacks.com. They only bypass 1amp of current though is that enough? I hope so. Since I'm all wired for it and it's $49 I guess I'll try it. Is anyone using one now...or is that TOP SECRET! Keep the info coming guys, thanks much. And by the way you guy's crack me up, I can hear it now..."Oh THOSE wires well yes they're for manual cell-condition checking yeah yeah thats the ticket manual cell checking. A BMS oh heavens no lol!

Bill

Bill,

The 'pulses' in my charts are due to the 1/2A shunts in my tppacks.com BMS board. Data was collected thru a PakTrakr and stored on my Sharp Zaurus. So yes - the board will work very well.

Here's a quick summary of why I don't have GPS verified top speeds for my bike yet. (Aside from the fact that I don't have a license plate on the bike yet - next week for that.): http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=8675&st=0&sk=t&sd=a

(ahhh, I don't mean that was ME in that post, just that I've spent time READING it and haven't ridden MY bike much. Yeah, that's it...!) ;)

AndyH
Offline
Last seen: 14 years 5 months ago
Joined: Wednesday, June 4, 2008 - 16:13
Points: 125
Speeds are Accurate

Battman, I agree I was wondering the same thing. Maybe it's not good news?

Yes - The top speed has been measured with a GPS and has been reported in the 5000 speculation thread - 63 with two aboard.

The speedo goes up to 60 - I've had mine past 60 in a gentle downhill into a headwind. Any more speed work from me won't happen until I have a helmet, license plates, and a solidly-mounted GPS - a hand-held GPS at 60+ probably isn't a good idea. ;)

Pages

Log in or register to post comments


Who's online

There are currently 0 users online.

Who's new

  • xovacharging
  • stuuno
  • marce002
  • Heiwarsot
  • headsupcorporation

Support V is for Voltage