I've found a lithium battery pack with BMS, 50 Ah 72v 28kg 3600Wh for 1000 Euros. I'm sure I can place 2 packs inside the Vectrix frame in series, totalling 144v 50 Ah 56 kg. Max voltage of the pack is 84vx2= 168v. Can the vectrix deal this overvoltage?
a picture of the pack next to my vectrix.
My pack is nominal 144v 60Ah.
my new charger charges up to 165v.
168v would probably work, you will have to test it first though.
Note: regen doesn't work until you have used ~10% of the batteries capacity when using 44 cells.
the original charger will only go to 155v, but it can be used for faster charging if using an external charger.
the MC is fine with the higher voltage.
acceleration profile changes,
peak power moves up to 100kmh.
acceleration is much the same between 0 and 70kmh, ramping up to full power at 80kmh.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
Great!!
probably it will work!
What range do you get?
let's imagine we install this battery. What issues should be taken into account?
For instance:
We'll use another charger. Do we need the original charger for something? or it can be sold away?
The battery gauge display will become absolutely useless?
What happens with all the battery sensors? Will the vectrix run without them? Do we need a special firmware?
many thanks in advance!
Hey R, are there any specifications or a web page for the lithium packs?
Cheers
Paul
The lithium packs come from the Goelix E-box. http://www.goelix.com/
I've asked for further details. If you find a scooter with this shape, you find this packs.
Hi,
If the higher Voltage (difference between 165v and 168v) is a problem you can probably figure out a way to charge to a slightly lower voltage. The decrease in capacity will probably be negligible and the cells should last longer.
Depending on the Cell spec's and layout I'd be concerned with heat. A major issue with the factory pack is poor thermal management.
Also what Cell Chemistry is used? If its LiPO be careful!
If you can wait a few months maybe some of the electronics from the forthcoming kit will help (assuming they are available without the Cells and the pricing is reasonable). Using inexpensive high quality cells in conjunction with the factory electronics could be an elegant solution.
Best Wishes!
Mitch
I get lotsa range :D (70km @ 100kmh, 90km @ 80kmh, 100km @ 70kmh).
the original charger is useless atm (until I get hold of a viable firmware revision)
so yes, sell it off.
without the charger, the fuel guage turns into a volt meter.
full bars = 136v.
no bars = 107v.
linear scale.
the battery sensors are just for the charger, nothing else uses them.
chuck them with the battery.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
Very interesting information!
Now it seems easier to upgrade the V's battery.
another question. the Guys at Goelix had lots of problems with different BMS. Is your BMS doing the right work? Have you checked the voltage of every cell?
I use the cell modules from this BMS:
http://www.evpower.com.au/-Cell-Modules-.html
available for retail here:
http://www.evworks.com.au/index.php?product=BMS-CM060-V6
they create a signal good/bad signal (on/off).
I use this charger:
http://www.evpower.com.au/-Elcon-Chargers-.html
That effectively makes sure the pack is top balanced, without overcharging any cell.
on discharge, its less elegant.
Although the BMS modules produce a good bad signal, I have yet to devise a way for the Vectrix to back off gracefully when the cell gets low.
The good/bad signal has high bandwidth, meaning it can be used for voltage sag limiting at the cell level in the ms time scale.
unfortunately, that requires reprogramming the motorcontroller.
I could use it to trigger the brake stand switch, but that would have the effect of the bike losing power suddenly when accelerating hardest.
I split alot, so thats not ideal.
the motor controller low voltage is 107v, which across 44 cells is average of 2.5v.
I could bottom balance, however, the charger is just your average charge to 3.65v average, then hold it there till current falls to 1.5A.
if I bottom balance, the lower capacity cells (of which there are 3, with 2007 manufacture dates) go over voltage before the 165v at less than 1.5A condition is met.
The BMS will just top balance the pack out again.
Without the BMS, the cells just get overcharged.
At the moment I am just limiting discharge to around 50Ah to keep within the flat region of the discharge until I can come up with a solution to discharge further.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
I find interesting to reproduce this antiscab's post here:
Hmmm...that sounds just like the original Vectrix battery! If the rider is very well educated in matters relating to battery management, and takes great care, then the battery will not be destroyed. But, for everyone else, it probably will die an early death!
This information may be used entirely at your own risk.
There is always a way if there is no other way!
haha yes, except I have one important advantage, I can go 3 x further :D
and no self discharge.
Now that I know there is a Vectrix BMS, I'll probably just wait for that to come out.
My present setup is not something I would make for someone.....
its all in getting your BMS to communicate with the controller.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
http://www.evpower.com.au/
these guys seem from australia!
Can anybody ask them about a BMS for the NIMH cells of the vectrix?? I'm afraid my english is not good enought to call them.
thanks.
That's not Australia....that's Perth :)
Margaret River actually (though I'm in Perth).
That BMS is really designed for Lithium, Nimh has slightly different requirements.
on discharge, you still want to know when the voltage has sagged below 0.5v IMO (because at 0.9v at low current a good cell can be at 50% SOC)
on charge, temperature or cell internal pressure is more important.
in the middle, an Ah counter suffices for Lithium.
for nimh, particularly for non refrigderated variants, keeping track of self discharge at the cell level is also important.
thats the ideal situation, IMO.
given the cells survive limited reversal reasonably well, voltage monitoring doesn't have to be cell level.
when taking this route, you have to limit voltage sag to ensure no cell is damaged.
The longer the string is between voltage sensors, the lower your maximum power is:
cell # min voltage ave V amps
1 0.1 0.1 825
2 1.3 0.65 412.5
3 2.5 0.83 275
4 3.7 0.925 206.25
5 4.9 0.98 165
6 6.1 1.017 137.5
7 7.3 1.043 117.8571429
8 8.5 1.0625 103.125
9 9.7 1.08 91.66666667
6 - 8 cell level should be sufficient to notice the voltage is low by 1.3v (ie cell reversed)
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
Did you mean at high current? Even then, I don't think a good NiMH cell will ever have such a low voltage when still 50% full.
I think it is too late by then. I would definitively want to aim at detecting the first stage of NiMH reversal - that is less than 1.3V, maybe closer to 1.0V. It takes surprisingly long to reach the full reversal stage - and I don't think the cells are very tolerant to the fully reversed state.
This information may be used entirely at your own risk.
There is always a way if there is no other way!
its all relative I suppose :)
I was thinking along the lines of 25A discharge, about what it takes to hold 70kmh, and a cell suffering from memory effect.
I think it is too late by then. I would definitively want to aim at detecting the first stage of NiMH reversal - that is less than 1.3V, maybe closer to 1.0V. It takes surprisingly long to reach the full reversal stage - and I don't think the cells are very tolerant to the fully reversed state.
[/quote]
fair point, perhaps aiming for a 0.5v minimum voltage at cell level would be better.
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km