Hi all ;
This is a post to understand the phases of the charge process of a brand new « vanilla » Lithium Vectrix Li +.
First I have to introduce myself : I am an electric scooter addict ; I have been using different electric scooters professionally for almost five years now and I've felt ready to buy my first Vectrix : a brand new beautifully white Li+. I go and see my scooter at night in the garage in admiration... Now I ride in comfort and as I travel almost 10 000 miles a year on a scooter (going back and forth in the centre of a town to meet my clients) it is easier and quicker for me to work and a much more pleasant experience. As you might have guessed I expect much from my V, and I rely on it a lot.
I have read many posts on Lithium conversions here but I've learnt little about Vectrix' own batteries. Few people have a Vectrix Li to report on V is for Voltage. I feel ignorant on recharge phases, temperatures and batteries as far as it concerns LiFePo modules.
Here is my concern. Although I can reliably get over 100 km of range on a single charge, I would like to take care of my batteries to keep them in a perfect shape as long as possible. I have read many things on LiFePo batteries ans if I am not mistaken, these modules are known to be reliable, strong, light and resistant to temperature to some extend. Best allaround modules technology can provide today with a long service life. How about GP Batteries modules in particular ?
When I plug in my Vectrix, I can read several phases : CC146, CV146 and EO146. Correct me if I'm wrong : constant current, constant voltage, end of charge ? 146 for 146 V overall ?
When I just plug, charging current goes up to 10 A (needdle reading 100km/h) I read for example : hi 331, lo 331, and on the left (where « est range » is usually) 130 V. I understand : « hi » for highest voltage module reported by the BMS, and « lo » for lowest voltage module reported by the BMS. Is it ok ?
Every thing appears to be ok, and all modules seem to be in balance.
After several hours of charge here are the readings :
hi lo charge voltage Amp temp C min-max
339 338 CC146 136 10 24 – 25
364 355 CU146 141 1,5 27-29
364 343 CU146
364 342 CU146
364 341 CU146
365 340 CU146 138 1 28-30
365 338 CU146 137 0,5
365 337 EO146 137 0,5 28-29
365 346 EO146 145 0,5 31-33
When the CC charge ends at 10 A, the low cell is at 355, as soon as the charge drops down to 1 A gradually, its voltage goes down to 337.
Clearly : the pack is not in balance anymore. There are two options. Or a module is weak, damaged, dead, or it has to be balanced and is far behind the others in the chargecurve.
If you take a low module and apply to it 10 A, I think it will go up and reads as much as its buddy modules ; but if you drop the current to 0,5A (CV and EO) if it is not as charged it will drop significantly its voltage, because it is late in the charge process. Thanks to the BMS, other modules stay at 3.65v waiting for it, giving up heat. I hope after a few other charges, it will catch up.
I would like your opinion on that...
When I read the GP batteries modules specsheet, 3.65 v seems to be pretty high for an end of charge : 3.65 x 40 = 146 v. My Vectrix takes loooong to get there ; and I don't think this is good for my modules to get up there each time and get as hot doing so.
Why is such an imbalance and can I deduce I have a weak cell ?
If I could open the batteries, the best thing to do is to take appart the lowest cell and do a charge in order to get a top balanced pack (or better yet : a bottom balanced pack). But as long as I can't do it (warranty and absence of knowledge – yet) I have to rely on the BMS to do so ; and it seems each charge my low module is going up a bit.
For the moment I hope each charge will bring the lowest cell onpar with the others, and I intend to charge up to 146v no more than once a month or less and go down to 3.1 maximum as far as I can.
Here is in insight on the Vectrix Li+, and I hope to hear what you think and recommend about it.
Thank you all.
Sorry for the double post...
Congrats on the new toy!
It sounds like Vectrix has changed the charging process a lot since the original bike. Mine is an '07 and I don't see the readings that you described.
One thing I discovered after converting my bike (Li-ion) is that the current readings (Amperage) is based on the inner speedometer (MPH) scale and not on the KPH scale. So instead of drawing 10 Amps during charging, it's actually drawing between 6 and 7 Amps.
I had one Li-ion cell that was .5V lower than the others upon installation and Antiscab recommended that I get a single-cell charger and charge that one cell separately to help balance the pack. However, after just one cycle of riding and recharging that particular cell measured only .02V different than the others. After a couple more cycles it was measuring the same. It seems that Antiscab's BMS is very efficient in getting the cells in the pack balanced. I have ridden a couple of hundred miles since the conversion and have had no problems at all. If the new Vectrix BMS is as good as Antiscab's it should keep the cells balanced.
As far as the temperature - it's winter here now and the hottest battery temp I've seen so far during charging is 24C. My old NiMH pack routinely got to 44-48C during charging.
Hi Dave,
A 6-7A charge rate is surprising....
is that 6-7A shown on the cycle analyst?
The speedo while charging shows current delivered to the battery, which on a lithium conversion is usually 10-11A.
At 240V, that means its drawing ~6.5A from the mains (240V*6.5A = 1560W = 10A @ 150V + 60W in losses)
If the cycle analyst is showing 6-7A while the speedo is showing 100kmh, the shunt resistance setting in the cycle analyst may be wrong.
That would also mean the Ah count is wrong (under-estimating)
The fact that the mph reading is the same as what the cycle analyst maybe showing, as well as a mains current reading may be a coincidence
re balance:
you know the cells are balance when:
For the conversions the BMS won't disconnect the charger
For a factory lithium Vectrix, the E0 stage will be very short.
I do like how the E0 stage times out after a while, holding cells at 3.65v isn't the best for them.
be aware that voltage is only a good indicator of state of charge on a LiFePO4 cell when it is either completely full, or nearly empty
as long as the cell is between 30% and 90% charged, it will tend to be 3.3v at no load
So while that cell that was low looks like it is as charged as the rest, it is unlikely to be :(
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
Sorry for the mis-information! Apparently I've had the Cycle Analyst setup incorrectly since I first hooked it up. I thought that the Cycle Analyst Install video indicated the mOhm setting to be at .750 mOhm... I changed it to .375 mOhm and now I'm wondering if that is the correct setting. When I plug-in now the Cycle Analyst says that it's drawing between 13.5 and 13.7 Amps, while the Vectrix speedometer still says 100 - 110 KMH.
Do the resistance settings vary depending on the type of battery/size of battery pack?
Meanwhile, I ordered the single-cell charger :-)
Thanks for catching that Matt!
It depends upon the shunt,
the formula is:
mOhm = mV / rated current (A)
If you bought the shunt from the same guys who make the cycle analyst, you probably have a 0.5 mOhm shunt
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
Hi Paco,
That will result in maximum service life,
While you ride, can you see lowest and highest cell voltage?
The bike probably won't let you ride until you actually do damage
how about max and min temp?
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
One question:
7 ampers at 240v AC?
or 7 ampers at 120-140v DC?
the nail usually uses the DC voltage inside the battery...
UPDATE: ok, I've just read the newer posts...
No, unfortunately when I ride I can't see hi and lo voltage. Or I don't know how to configure it. The booklet is not special for the Li version, everything on it refers to NiMh. Even when it's on and not riding I can only see temps and not voltage. I have to plug it to see voltage. Maybe there is a way to see it that I haven't found.
Usually temps are between 20C and 24C when the ambient temps shows 20C even while riding. Temperature goes up only at the end of charge.
Yesterday night, my Vectrix was recharging and the EO stage took really long (only at 142 v though) and hi cell reached 3,70 with a HighCell (or something) message and red battery warning. Fortunately I was monitoring the charge and unplug right away. Next time I will watch closely as I don't trust long EO charges very much.
Thank you for your insight. I will keep you informed.
François
I went back through my emails (I ordered the Cycle Analyst in July) and found this:
I changed the mOhm settings on the Cycle Analyst to 0.5 mOhm and now the numbers make more sense :-)
Hi Paco, welcome!
I've a bike just like yours, a white VX-1 Li+, but I'm also very new to it, or is it that she's new to me? :)
Anyway, don't worry, your bike is fine, your cells seem fine to me at least.
The meanings you refer to are mostly correct, AFAIK:
CC = Constant Current charging
CU = really is CV = Constant Voltage charging
EO = really is EQ = Equalization process (if possible try not to abort it, it can take several hours, don't worry, it's levelling your cells)
EC = End of Charge - The bike instruments will shut off when left at this stage for some time, it confirms to you it has finished.
As you use your bike more often, you will see your cells coming together more easily, don't worry to much for now, it all seems fine.
If you're from Spain or Portugal then I invite you to join Prius-PT.com as well, as we try to create a parallel community for the Iberia region.
But please don't leave this forum, it's all the world gets together, it's invaluable!
jprates
Hi, I am happy to see that I am not alone with a Li + here !
It's true that I felt a bit lost with this bike, a booklet speaking of NiMh only, and forums about NiMh or home made conversions.
But I learn every day about this bike and I enjoy it a lot.
I didn't know that EO meant Equalization; it makes more sense now. It is true that cells tend to come together.
By the way I am not from Spain or Portugal and can't read portugese...
Hope I will read more from your Li +.
How many kilometers have you driven?
How much range do you get?
Do you let your bike plugged at night? (Do you trust your BMS?)
And last question : how often do you get "EO" on a Li + ?
Thank you !
Hi Paco
I also have a Li+ Vectrix. My Mileage is env. 2500 km now.
Concerning Charging: my Vectrix has on every Charge all cycles:
- CC156 60% of time
- CU146 10% of time
- EO146 30% of time
- EC146 End Charge
Greetings from Switzerland, Thomas
Paco
You should let the pack equalize on every charge. The cells will always be out of balance at the end of a discharge, and more so every time if you dont allow them to balance. Trust the BMS. If you havnt allowed the EQ in a while, the process could take a long time. The fully charged cells will be fine, they will not heat up. The EQ current is shunted around these cells. Only the lower cells will actually have the EQ current going thru them.
Hi Paco,
Like ThMeier has mentioned, the BMS cycles through all phases at every charge, unless of course you unplug it first.
Yes I do trust the BMS, heck if I did not trust it I would not ride the bike at all.
My daily routine is like this, give or take some minutes:
00h00 @home Timer controlled socket at home turns current on, Vectrix is free to charge at will (cheap electricity) while I sleep;
07h00 @home Timer controlled socket at home turns current off, Vectrix will be 100% charged most times, but not always;
08h45 @road On the way to work, only 7km away from home, easy ride even if not fully charged;
09h00 @work Plugged in till I eventually need to go out to a customer or errand or lunch time - charge & equalization usually done;
During day-time I try to charge at every stop, mostly in Lisbon "Mobi.E" free electric charging stations, but also free at most shopping malls;
Whenever back at work the bike is always connected to grid. Some days it stays connected over 8h per day there;
20h00 @home Back on timer controlled socket, waiting for midnight for another cheap charge.
All of this resumes to one sentence: Whenever you park, try to charge it, leave it charging, it won't hurt, it will only help your battery.
This is my understanding so far. If I'm wrong then I would appreciate anyone would prove me wrong so that I can learn and evolve.
EDIT NOTE: Forgot to answer your last question - I'm over 4000 km so far, marking today exactly 2 months use.
Cheers mate,
jprates