Does anyone have any recommendation for maximum battery temp before recharging?
I am thinking about long term battery health. There has been a lot of discussion about the optimal temp for recharging. The efficiency of the charge drops as the temp rises.
I have until now mostly ignored the C degree temp number when I plug in. But I can see now from reading that this is important.
I just plugged in my Vectrix it was 32 degress C. I recall in the past seeing numbers in the high 30s when charging. Perhaps 36 degrees C or so.
For anyone with knowledge about this, what is the maximum number you would recommend? For example, if I see 40 degrees C is that a poor number and I should instead allow the Vectrix battery to cool down first? I am just seeking that threshold number to guide me.
My current recharge strategy doesn't turn on my timer until 10 pm in the evening, then it has a 6 hour time block to charge.
But sometimes I recharge in the middle of the day if I have the opportunity for a few hours. This involves plugging in a warm/hot battery that has been partially discharged.
http://www.batteryuniversity.com/partone-14.htm
My guess on this one has been, don't charge a battery in a place you couldn't stand to be, like over around 100 F.
Be the pack leader.
36 volt sla schwinn beach cruiser
36 volt lifepo4 mongoose mtb
24 volt sla + nicad EV Global
What is the range of battery temps after a ride people are experiencing? At what temp do the cooling fans come on?
With ambient temps of 10 to 20 Deg C, I get battery temps of 26 to 32 Deg C, the fans have never come on so far.
Regards,
Peter
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Central Scotland
Highest I have heard of was 47°C. To get that temperature, do one hard, uninterrupted ride, starting just after the battery has charged, on a hot day, until the battery is almost empty but still has good performance. Plug in straight away...and there is your record battery temp! Not recommended!
The "bathot" warning together with the red battery telltale come on when the temp hits 45°C, I believe.
The battery cooling fans come on earlier, about 40°C but I am not so sure how exact that number is. It might be between 36°C and 44°C.
What to do when your battery is hot:
If it is very hot the fans will run, but only for a few minutes; this is good and what your batteries need.
After that use a device like the ABCool 12V power supply to further cool the batteries before plugging in the charger.
If you do not have an ABCool, or like your warranty too much, plug in the charger after letting heat spread through the battery from hotter to cooler cells. You'll have to make your own guess how long that takes. I guess about 15min max.
You could find out how long this takes by plugging in repeatedly for a few second and noting the battery temp. As only the highest of the 12 temperature sensor readings is displayed, it will initially rise (as the air in the battery compartment is not being replaced by wind or fanning), then fall a bit when the temperature equalizes between the 12 sensors.
After small initial changes the temperature falls very, very slowly to ambient temperature. Think days, not hours!
90kg of metal and chemicals, well wrapped up, that stays warm a long time!
The batteries do not cool down significantly without fanning over just a few hours.
Plugging in sooner rather than later will reduce the overall time that your battery spends in a hot state.
Ni-MH batteries only heat up during the second part of charging, so, plugging in early helps your battery.
You might want to avoid charging if the ambient air temp is very high, of course, particularly the second part of charging.
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
Only once, at the end of my first deep discharcge and never since. C'mon now - it's so cold in Summer here there's hardly any reason for them to turn on!
- Raymond
Very true, but nice to know.
Anybody notice any loss in charging performance / bike performance with low temps, in the next few months over night temp will be into single figures here!
Regards,
Peter
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Central Scotland
pyjohnson, Do you really ride in Scotland when it is that cold? Even during the day it must be cold.
I live in Seattle and I am anticipating that my Vectrix will be mostly in the garage for 5 or 6 months starting in November.
I've been riding motorcycles all year round for the last 15 years and I don't expect the vectrix will be any different.
As long as the roads are ice and snow free that will be my transport to work.
Regards,
Peter
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Central Scotland
Morrison
Believe that a better question is WHAT THE OPTIMUM TEMPERATURE FOR CHARGING ?
The answer is room temperature 25 C
All charger are designed for room temperature and compensated for higher or lower temperature .
Have a couple lepton with Nickel-Zinc pack in them , after any use whatever.I remove the battery cover ,and blow a fan on the whole area for a long as I can .
The internal charger of the scooter has a fan that goes on when charging ,it only cool the charger circuitry , does not do anything for the batteries .This design is almost 8 years old
Suspect that most EV manufacturer are more concerned about securing the batteries pack in place ,placing foam and other items so to prevent accidental shifting or shorting out of the pack ,
they have not given much thoughts if any consideration to cooling the batteries.
Have seem some high performance scooter being assembled with exposed batteries pack ,very good for cooling them , but problematic for keeping connections secure and dry.
Not having a Vectrix to examine,like to believe that they design it with appropriate thermal management in place,the internal fans providing cooling for the charger and batteries .
Toyota have been improving their power pack each new generation,going to ever increasing pack voltage ,( reducing current) and improving the thermal management of the pack.
Any serious designer of EV would do well investing time studying Toyota each new generation of batteries pack.
They are not redesigning the pack because they don't have anything else to do, the Japanese are famous for analyzing
their test result and continuously improving the product , this case " the power pack ".
And no I am not affiliated in any way with Toyota or even own Prius (would love to), have driven several and examined their power pack ,tremendous design went into it , very impressed ! ! !
Considering how many Prius have been sold ,doubt that if there had been a 0.001% of the problem encountered by this web site EV user their sale would have risen as fast .
Interesting that they designed in the lowest impedance cell available ( HHR650D 2 milliohms at 6.5 A/H )they where just lucky ...........
Ounce more,it is internal impedance which determine how much heat is created both in the charging and discharging mode .
HEAT & LOSS & INEFFICIENCY RELATED DIRECTLY to IMPEDANCE
HCT,
I guess the point of my original question was to determine when NOT to charge. I am looking for the upper threshold (***WARNING***) for when it might be advisable to wait. I don't need to know the perfect time to charge.
I think most of us, most of the time, will be in a standard range where it doesn't hurt the Vectrix battery. 25 C to 35 C likely is all within acceptable ranges. My goal is to have an idea of when those rare times happen that it might be better to wait.
According to Mik, he has seen 47 C on his battery meter. The past few times I have charged, I have seen 33 C.
Mik is also of the opinion that it is better to have the fan on when it is that hot, to better spread the heat faster. So it might makes sense to plug in the battery ASAP even if the temp is high.
This is all just speculation trying to figure out how to have best practices for a new Vectrix owner.
Does the internal fan on the vectrix go on anytimes during hard driving on a hot day ? or does it only go on when AC power is applied ?
Do I understand correctly that the cooling system designed by Mik ABCool 12V power supply for his Vectrix , are fans supplementing the internal fan that goes on when a charging is initiated ?
He is absolutly correct in wanting to lower the temperature of the pack as fast as possible .
It is possible to tell whether the internal fan in the Vectrix ( does it turn on when it charging ? ) cool the batteries and charger or it is like my Lepton, only provide cooling to the charger assembly ?
.
If it is like my lepton , then they may have some sensor preventing the charger ( and fan ) to go on when the battery pack is above a certain elevated temperature ,and as Mik said without the fan blowing
the batteries will take a very long time to cool and start the charging cycle .
The more I review Mik postings,starting to suspect that Vectrix did not take into full account the Australia temperature situation,and maybe it is one of the reason Mik been having so much probleme ,
Vectrix slow response must forced him to take matter into his own hand and come with the additional cooling,would have expected Vectrix to show Mik some gratitude in resolving this issue.
As mentioned before ,I remove the batteries cover on my lepton to allow cooling and in addition have a fan blowing on them .
Can this be easily accomplished on the Vectrix ? .
HEAT & LOSS & INEFFICIENCY RELATED DIRECTLY to IMPEDANCE
The Vectrix fan will come on as you are riding, while charging and even while it is just sitting there in the off position and unplugged. If the battery is too hot, the fan will be running.
I also just got home from a long ride and checked the temp. I plugged in to check the temp and it was 36 C. The Vectrix fan stayed on even when I turned off the Vectrix and I was not plugged in. So I decided to leave it unplugged to see how long the fan would stay on with the Vectrix turned off. The fan stayed on a few minutes, then stopped. I plugged it in and the temp was 35 C.
Perhaps that is the goal of the Vectrix BMS. Maybe they have designed it to try to keep the battery temp at 35 C or below. I will need to do more testing on this issue to be sure. Perhaps Mik already can tell us.
Guys, I found a great interview on the Youtube from a user named liveoilfree.
He drives Toyota RAV4 EV and his advice (and I fully agree with him) on using NiMH is that for the long NiMH battery life, do not charge them fully each time if it's in a hot spot, because the end of the charging produces heat and heat is bad for NiMH battery. If you do not need the full range of the vehicle until the next charging, charge the batteries only until they start becoming hot.
Also if you start driving with a fully charged batteries, the regen braking power will go to heat instead of storage.
Here's a video: http://www.youtube.com/watch?v=EoCZaA9D0WM
Watch his other videos. They're great!
Thank you for the info,very glad that Vectrix did thermal management on their Scooter .maybe not quite enought for the Australia climate ! Is it possible to tell whether the fan is blowling on the the batteries ,controller, or charger or all three ? are there more than one fan ?
Mik
Somewhat pulze by this statement , would expect all the cells having the same temperature rise ( of course I am assuming that all the cells are all right having same intermal impedance ? ) there may be a sight temperature difference between the outside cell and inside cells,(not enough to have hotter and cooler cells )suspect that those twelve sensors on the batteries assemblies are there to catch any cell having higher impedance ( by the same token lower capacity)
Mik is it possible that your scooter software is not as updated as the ones being sold now?.
Maybe a change was made recently to correct the temperature probleme .
HEAT & LOSS & INEFFICIENCY RELATED DIRECTLY to IMPEDANCE
I do not think this matters with the Vectrix fan system. The charging process cools down the battery, so it becomes cooler by the end.
I have been watching mine tonight because I am intereted in the battery temp.
It started with 3 bars and a battery temp of 35 C after a 33 mile ride.
It has been recharging for 1 hour 15 minutes, it has 11 bars and the battery temp is now 30 C.
So throughout the charging period, the temp declines significantly. So the end of charge battery temp is actually much cooler than at any other time.
Perhaps the RAV4 EV was not as good at managing heat in the battery. The Vectrix fan system clearly is able to stay on top of the issue.
This is just my quick observation. Perhaps other Vectrix owners have had a different experience.
What is the temperature of the battery after 2 hours of charging and beyond?
NiMH start getting warmer after they are 80% full.
Andy, I don't think you have to worry about regen heat issues. Unless you start off at the top of a very long, steep hill, there's no way the regen brakes are going to overcharge the battery pack. If you used a tenth of a mile's power, then did a slow regen brake for a tenth of a mile, you're still going to be less than fully charged. Regen will not put back as much juice as an equal distance of power will take out.
There are 5 fans in a standard Vectrix, 6 in the Vectux.
2 fans on the charger; 2 fans in the battery compartment; one fan on the heatsink of the motor controller; and the additional fan in the Vectux cools the additional 240V to 12V power supply.
The MC fan is the strongest and loudest, and the only fan with variable speed. It comes on whenever the throttle is "hot" and can stay on after riding, for longer after hard rides in hot weather. It then stepwise slows down until it turns off.
The two fans on the charger are very quiet and can barely be heard because they run at the same time as the two larger battery compartment fans, i.e. during charging.
The 2 battery compartment fans sometimes start to run "spontaneously" in hot conditions after riding or after charging. The wind or the fans running keep temps down until the charging is finished or the ride is over. The fans go out for a minute, then come on again once the temp in the battery compartment has risen to a threshold, somewhere between 36°C and 40°C I believe.
They may also start to run whilst diving in hot conditions.
When charging starts these fans usually start with a few seconds delay between them. This also happens most of the time, but not always, when the ABCool turn these fans on.
Close, but not quite right.
The ABCool 12V power supply is a system that uses 240V from the grid to power up the 2 battery compartment fans, completely independently of the Vectrix BMS; it also ensures that the battery compartment fans only ever get 12V supply from the BMS or the ABCool.
If it's too hot or the battery is/gets too hot, the fans continue to run with the charger in "tr" mode, with very little power flowing into the batteries.
I doubt this very much. It was not the heat that did it. The problems could and should all have been solved, but Vectrix staff chose to ignore my detailed reports of these problems. I generally posted them on V after I could not get a reply from Vectrix.
I had to fix the gear box myself because they continuously ignored my reports of its unacceptably uneven, noisy and vibrating operation. They also introduced new problems each time they worked on the scooter (or exchanged it with a worse one).
The exchange scooter, now called the Vectux, had severe range problems: Initially only 9km range, but the battery was still displayed as 3/4 full when the scooter could hardly move any more! This improved only very slowly with further deep discharges. Here are the details of the infamous start of the battery still in the Vectux today... The reply of the Vectrix Australia salesman when I described the situation: "It is working perfectly".
I also had 2 blown mainfuses before, and one after the cancellation of the warranty.
And the Vectrix technician damaged my motor controller board by not using a torque-wrench and over tightening the motor cable "C", which then burned a hole into the board...Three separate Vectrixes in Australia have had that failure!
But he blamed it on me instead, saying it was due to laying the Vectux on it's side to fix the gear box.
The ABCooling is pro-active, to prolong battery life time. It has nothing to do with the over 50% downtime I experienced before they canceled the warranty. I developed it after I had to take the Vectux apart to fix the motor controller damage caused by the technician.
I hope that this whole problem of disappearing bars and low range is maybe due to incompletely formed batteries, which would mean it will get better over time.
No, difficult to do and dangerous.
But, accessing the electrical connector to the 2 battery fans is easy. 2 screws to take the front seat off and you're there! Put 12V DC (5A minimum) through there and you have the best possible cooling. But noisy, of course.
HCT, could you please try to interpret the strange behavior of my Vectux battery? If high internal resistance was the problem for the abysmal early range, then it has clearly gotten better...
Back when I was still the only one posting experience reports on the Vectrix I wrote this for people like you:
I'll try to provide details of what I observed in regards to my Vectrix' charging process here, hoping that those people amongst you with years of hands-on experience with Ev's, batteries etc. can make sense out of it,
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
I meant to say: That is the only reason I can think of to wait a short time before plugging in, to let heat levels equalize. It will not remove significant amounts of heat energy from the battery.
Of course!
It is not an immediate problem. The disappearing bars and low range are independent of temperature, I believe.
Only many months or, hopefully years, will tell how much of a problem temperature is.
The current Vectrix temperature management is a compromise. They want it to be easy, as in just plug it in. And they want it to be fast to recharge. And they want a good range.
And all without the rider needing to think, plan, switch or measure much...
That's why the ABCool is an improvement for me: I know when to turn it on, and when not.
It will in all likelihood improve battery longevity; and also improves range due to charging "just in time" before riding if needed.
But it is much more complicated than just plugging in!
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
Great, thanks for that. I was trying to find answers to just that question: Is there any reason to fully charge the Vectrix when only part of the range is needed?
Taking into account that storing Ni-MH is apparently best at 40% charge state, and they do not heat up in the early stages of charging....
I also thought this might get rid of the damage done to the weak cells by discharging and recharging the 102-cell string. If the difference between highest charge level and lowest discharge level is kept below or at the capacity of the weakest cell, then this cell would not get over-charged or reverse charged and will not suffer more rapid damage.
Question: Is the "trickle" or "equalization" charge at the end of the charging process necessary?
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
Not always. But it is recommended to balance cells once in a while.
Trickle charging without a balancer is a crude way of balancing the batteries without the balancer.
If you had a balancer (balanced charging), you would charge every cell separately (like my LiPo cells for the RC Helicopter).
If you didn't, trickle charging is a crude and a cheaper way of balancing the cells. Those who are already fully charged, turn the overcharge electricity into heat, and those that aren't, are still charging. The result is balanced cells.
My suggestion for you would be to fully charge the bike once in every 10 charges. If you really don't need the whole charge for a ride, you really don't need to charge them to a point where they start to produce heat. And heat is very bad for NiMH + you're throwing electricity away, because it goes into heat + you avoid 10% self-discharge in first 24 hours.
Thanks!
I can hardly wait 'til you get your Vectrix!
Am I right to assume that the absence of cables (other than battery plus and minus and 12 temperature sensor cables) to the batteries means that there is no cell balancer on a Vectrix?
I will change the charging pattern by the ABCool 12V power supply so that the Vectux battery stays between 9 and 14/17th bars full. That should give me 20km range with 10km reserve with full power and another 5km with crawling power.
There will be times when I need the full range to start with and there will be times where the need to get somewhere with less pushing makes a BaLPoR unavoidable.
These events will probably happen just frequently enough to do the occasional balancing and deep discharges as recommended!
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
Me too :-) I will leave for holidays on Sunday and will be gone until August 31st. My Vectrix should arrive on September 5th.
You assume correctly. If Vectrix has a balanced charger, every cell would have it's positive cable, but they could all share one minus cable.
Something like this:
Each one of these 5 connectors can balance charge 3 LiPo cells. They all share one minus, but each has it's own plus. More the cells the battery pack has, the wider connector it is and there are more plus(red) wires. Obviously, the Vectrix has 102 cells in series and that would require very expensive charger and a lot of wiring. The Vectrix made a correct decision in doing as they did. High Quality LiPo balanced chargers with 100W charging power (6 cells = 22.2V * 5A/pack (1C)) costs aprox. 100 EUR. Imagine the cost of 1.5kW balanced charger. Even the charger as it is, must cost a lot.
Yes :-)