After a 'normal' (no EC) charging, my VX shows usually 142-143 Volts.
If the charging session was completed in the evening, the next morning when I start the VX it shows 'just' 140-141 V .e.g: 2 volts 'lost' overnight.
I doesn't matter if the VX was unplugged at the end of the charge or remained plugged till the next morning.
Is this a know issue? (that's why I posted in other thread that sometimes I do an extra-topping about half an hour in the morning...
Thanks
Claudio
The voltage of a fully charged battery is somewhat variable if no load is applied.
That is to say, in fully charged NiMh cells the state of charge and cell voltage bear only a tenious relationship to each other.
When serious current is drawn from the cell, then cell voltage will drop a little and then settle while a reasonable charge is still in the cell.
Only when the cell is near to its discharge state, will voltage be an indicator of cell charge.
In short, with 102 cells in series, a small variation between cells and their voltage is to be expected. The full battery voltage will therefore be somewhat variable before any current has been drawn from the battery.
With continued cycling and the well documented lack of effective cell balancing in the Vectrix, variations of only 2 Volts between charge and useage are not unexpected and I wouldn't worry.
Now, if range suddenly drops, battery light comes up after 10km and top speed/accelleration suffers, then I'd worry.
Cheers
Paul
Due to the excellent info posted by Mik and others, I am very aware of the battery temperatures. In hot weather, the battery will heat up due to charging and it seems to me that a quick, late topup may restore the 'missing 2 volts' but will also heat up the battery just before a ride. Not good.
On the other hand, I have noticed a distinct self discharge and corresponding attenuation of range after only two days of no riding/charging.
It is my habbit to topup charge on the evening before a ride to ensure I have the full 30km range that my Vectrix can deliver.
Bring on the lithium cells!!!!!!!
13900km so far, will my Vectrix last the distance?
Cheers
Paul
Hi, Thanks a lot for the quick reply.
As said, sometimes I do the 'additional topping' early in the morning (about half an hour after the overnight charge shut down).
Taking into consideration the temperature sensitivity, I do this only when the weather is below 30 C and when the ride will be short (less than 10 minutes at 'urban' speed).
What surprised me from your comment, is that your VX makes '30 km/ full range'.
That sounds too low to me. Did you mean 30 'miles' perhaps? Or probably 30 km at full speed (90-100 km/h)?
I found that my VX makes mostly about 60 kmts between charges (draining the battery to '0'). I always drive in a very conservative way, even a dangerous low speeds (70 km/h) in 90-100 km/h highways.
I put in other thread my thumb rule for range:
speed+range=110; or in other words: at a certain average speed, the estimated real range (no need to make hard calculations, acceleration, etc) is:
(RANGE= 110 - AVG Speed), for example
If the average speed is let's say, 60 km/h, then:
110-60= 50 km range,
If the avg speed is relatively slow ~ 40 km/h (in the city), then:
110-40= 70 km range,
An finally, squeezing the VX hardly at about 100 km/h
110-100= just 10 km range.
I recall one forum member which fully agreed with this simple rule.
It may be really interesting to see what other members think.
When carrying a pillion passenger, I reduce 10 km from the result.
30km? mmmm I hope that was a typo error or you reach 30 km a constantly top speed.
Thanks!
Claudio
G'day Claudio
Yes, I read with interest your 110km rule when you first posted it.
My average speed is perhaps 80kmh for my 20.7km ride to work. I charge at work and so a full tank of electrons will get me home again no worries. My range of 30km is not miles.
80 + 30 = 110
Your rule works Claudio!!
The treatment that the Vectrix bikes recieved before and after the shipment reached Australia has been discussed at length. But the upshot is that range for any bikes on this continent is severely restricted.
In the first months of my bike, from March'08 onwards, my range peaked at perhaps 45km. A few issues and popped cells later, together with the October '08 software update and range has indeed dropped to about 30km.
Vectrix Australia have helped me out as best they could all along, with replacement motor controller, charger and cells at no cost to me. Thanks.
However I am left (as we all are) with a fundamentally flawed electric vehicle whose key system (battery management) is a shambles at best and downwright counter productive at worst.
Don't get me wrong, I realy enjoy the V and look forward to the ride to work every day. I am realist enough to know that as an early adopter, the product is not yet perfect and the next improvement of lithiums may just make an overall good thing better.
Cheers
Paul
Claudio, i also agree with you rule, it works for me.
Reffering to the loss of 2 volts overnight, it is pefectly normal, it always happens to me. My Vec gets full charged at 143 or so and next morning when i go, its at 141.
The other day i did the "gauge calibration" and after recharging i got 147 volts (a good indication that the calibration was succesful) and just as i was leaving to work, i rechecked and it was already fluctuating betwen 145 and 147, so i took a pic and some video. I dont know if its normal that the voltage fluctuates so much.
Here is a pic
Hi Folks,
I'm really happy that my thumb-rule works for others: that means that it is could be a common base line for comparison and probably a good tool for real world range calculation.
The rule was depicted mostly based in empiric data, after I analyzed the manual's suggested range and figured out that the battery depletion is almost linear (taking into account also wind resistence factors, etc).
That being said, now I'm confident that, for example, if I've already run let's say 20 kmts, and now I'm planing to ride the next kmts at about 70 km/k, I apply the same formula:
110-70= 40km-20 km already done= 20 km remaining.
Just a question: what is the calibration thing and how do you do it?
Thanks!
Claudio
This post was really about voltage. Upon completion of the charge, my voltage is typically around 143V. The next day, may be 139V. A day later 137V. A week later 133V. So we are not just talking about a couple of volts here. It drops about 10V in one week. Anyone wan't to weigh in?
Typical NiMH self discharge?
Hello All,
Lost volts. What you are seeing is the effect of a twofold action.
The first effect is that of a charged battery standing after charge. When a battery is charged, extra voltage is required from the charger to 'push' the charge current into the battery. An example we are all familiar with will be the lead acid 12 volt car battery. Nominal voltage is 12 volts. Empty voltage is 11.5 or less. Full battery is around 12.6volts, All of these figures assume that the battery has no load. However, to charge the battery we used a voltage of 14.2 up to 15 volts.
When the battery is 'full' the current input drops to near zero and the terminal voltage is almost equal to the charger output voltage. If you measure the battery voltage immediately after a full charge you will get 14+ volts, if you then make periodic measurements you will find that the terminal voltage drops eventually to the 12.6 volts which indicates a full 'off load' battery.
I am not suggesting that the NiMH follows exactly the same figures because it is a different chemistry, but it will follow the same pattern, in that the final voltage 'on charge' will drop following the removal of the charging source.
Second effect is that the Vectrix electronics are always powered.
Approximately 6 mA is the figure we are told is always being drawn from the battery. Remember also there are the 'internal losses' to account for. these 'losses' are higher when the battery temperature is higher, hence the need to keep the battery as cool as is possible during storage or when not being used.
So, your lost volts are now accounted for, as also is the 'lost power' after the Vectrix has been standing for a few days.
I have some 'internal loss' figures related to temperature taken from Duracel literature, they indicate the following potential losses.
At 0 degrees C losses are 4% to 10% in 30 days or 0.04 to 0.1 Ampere Hours each day.
At 20 degrees C losses are 14% to 28% in 30 days or 0.14 to 0.28 Ampere hours per day
At 45 degrees C losses are 54% to 80% in 30 days or 0.54 to 0.8 Ampere hours per day.
The above figures would increase by the Vectrix current drawn, which equals approx 0.2 Ampere hours each day PLUS another 0.5 ampere hours for every hour that the cooling fans run following a charge.
The above temperatures are NOT the ambient temperature, they are the Battery temperature, which is (nearly) always higher that ambient (Battery temperature drops slowly, mine at the rate of about 1 degree per hour with a temp difference of 10 degrees ambient to battery).
Although the battery is a 30 Ampere hours battery, only about 24 Ampere hours are usable, so each ampere hour lost can represent a kilometer or two of lost distance.
And it all started with a simple question :-)
The Laird
Hi RaDy, you said: "The other day i did the "gauge calibration"... could you please elaborate what the calibration gauge is and hot to do it?
Thanks!
the gauge calibration consists of getting the maximum battery capacity (no memory effect) by doing 2 "deep discharges" but only until you get the red battery light, it is recomended once a month or so. XVectrix made a very good explanation of "gauge calibrating".
Here is what X Vectrix wrote :
The calibration routine consists of two parts that must both be done to correctly calibrate the fuel gauge and charger. If the sequence is done incorrectly the first time you will have to perform the same routine multiple times to get it right. This is what happens: When the new code is loaded, the battery capacity and fuel gauge are set to a default capacity of 30 Ahrs. To begin the calibration you must discharge the scoot till the battery icon comes on (flag 1). It doesnt matter what the state of charge is before you do this, as long as the icon comes on. This discharge lets the charger routine get a fix on a known state of charge (ie. discharged, not deeply discharged). Then on the next charge the battery will charge as if it is 30 Ahrs (plus a little). You must allow the charge to complete (flag 2). On the next discharge (assuming flags 1 and 2 are set) the SW will measure the output of the battery if you discharge it till the icon appears (flag 3). This new capacity replaces the default 30Ahrs and is used to scale the gauge and to limit the subsequent charges.
What can go wrong? If you do your initial discharge, then charge, then wait too long before the next discharge (battery self discharges) you will get a too low of capacity on the discharge. Subsequent charges will not fully charge the batteries. If you get to flag 2 then do a bunch of shallow discharges/charges you will not get an accurate measurement at the next flag 3.
So, what do you do if it hasnt been done correctly? Do it again several times in a row. The capacity is averaged each time flag 2 is followed by flag 3. (flag 2 is reset whenever you plug in the charger). By doing several of these in a row you can quickly get to the actual capacity.
The battery does not require a deep discharge for the icon to appear. In fact you may still get several miles of good performance after the icon appears. The icon is programmed to come on when the battery can no longer supply 7KW w/o falling below a certain voltage. This is WAY different then on the old SW.
Things you might see on the dash occassionally when the battery and gauge are out of sync: If the battery level is higher than that indicated on the gauge, when the gauge reaches a little more than one bar it will stall until the icon appears (indicating the battery has caught up..or caught down) then it will decrease as usual. If the battery level is lower than that indicated by the gauge and the icon appears, the gauge will begin decreasing at a higher rate depending on how far off it is. If you cycle the power the gauge will clear.
OK I think this is long enough..
here is the link : http://visforvoltage.org/forum/7247-sudden-drop-range
Its worth it , to follow his instruccions!
Enjoy your Vec :)
RaDy