New ebike with older Phylion battery

[Onweels]

I just bought my first ebike in mid September 2008. I live in an out of the way rural area and shopping around for the perfect bike wasn't easy.

In these parts our winters usually have a temperature of 4 to 10 degrees Celsius, and in the winter I need my bike for transportation into the closest town to buy groceries. It is hilly terrain and round trip is about 10 miles. In the summer I hope to make it to a town where I work that is 12 miles away. This will include a slow mostly uphill climb over 6 miles, the rest being all downhill.

The ebike was made in China, and except for some information on the battery, and the sticker of the Canadian company that is selling it, everything is in Chinese. It is a folder and I am told it has a 360 watt brushless hub motor It has a 36 volt 10 amp hour lithium battery made by Phylion.

There is some basic information on the battery, which is in less than fluent English, such as to recharge the battery for 2 hours for every 2 months not used, to not connect the terminals, immerse the battery in water or other solutions, open the battery without a manual or expose the battery to heat or "shining", and to avoid riding in the rain.

On the battery it says

XH370-1OJ

Phylion DC37.0 V

Using information I found in other threads here, I have translated my serial number which shows my battery was manufactured on July 11 2007.

I chose this bike because out of the bikes and sellers I had to chose from, it was the one that seemed to have the most power on hills and which also had the lightest weight, so I can lift it onto a bus rack. It is also a folder, which will allow me to make a variety of choices as to how I want to go home after a long day at work, or if the weather gets wet. It does that here quite frequently, even when the weather forecast is good.

Although I am happy with the bike and it has a one year warranty, the people I bought it from are extremely vague when it comes to technical support. I think they nice people who are selling the bikes because they like the idea of environmentally friendly transportation, but they aren't very skilled at the mechanical side of things. They told me the instruction manual they got with the bikes is all in Chinese.

So, I have been searching online for the information I need to know to take care of my bike and battery, and some of what I have found has raised some concerns.

When I first saw my bike at the store, the tires were flat and when the sales person sat on it and twisted the throttle nothing happened. So apparently the battery was discharged to the point the motor did not work. Once air was put in the tires they have stayed full, so I am pretty sure it had never been ridden and had just been sitting for a long time after being shipped from the factory in China. At the time I wasn't aware of the potential problems of an old or overly discharged battery.

The sales person put a charge in the battery and some air in the tires and all seemed to be well. The bike has enough strength to propel me up gentle hills without me even pedaling and on a very slight uphill there isn't much point in pedaling, as the motor has more strength than I do. I do have to pedal on the substantial hills but except for small sections that are very steep it's easy. There is one very long steep hill in my area that I walk the bike part of the way up. I'm not sure if the motor would cut out, but my legs couldn't make it.

The battery is in a rectangular metal case with black plastic at the top and the bike turns on with a key that goes in the battery. There is no continuous light showing me the state of my battery, and I have to get off the bike in order to push a button on the battery case. This shows three green lights when the battery is full, two when it is 1/2 full and one when it is getting low.

A couple days after I first bought it, I did the 10 mile round trip to the nearest town.

On this first trip in 15 C weather the battery showed all three green lights after the first 5 miles and was down to two at the end of 10.

Rainy weather and my work prevented me from riding again for about 3 weeks. The bike is stored in a unheated shed. My next 10 mile round trip over the same terrain took place after a night with lows of 3 degrees Celsius. On this trip the battery showed 2 lights after 5 miles ( it had all three before) and was down to one after 8 miles. It still seemed to have enough power, and still had one light on after I got home. Though what the battery lights showed was different, I only noticed a slight difference in power, and it still went up all the hills with only slightly less power than before.

About 10 days later at similar chilly temperatures I rode the first 2 miles of the aforementioned round trip which was mostly uphill, and when I checked my battery light at the top of the 2 miles, it was down to one light, though I didn't notice any substantial difference in power. I was thinking maybe I have a bad battery ( the bike supposedly will do up to 40 K on one charge ) So then I rode the mostly down hill route home and once I got there I checked the battery and saw it had two lights. So either my battery gained back some of it's charge, or the battery lights don't show what is really going on.

Because of the warnings I have read about the dangers of over discharge I am afraid to ride my bike till the power cuts out so I haven't been able to test the limits of it's range.

So I have a few questions which I am hoping Flecc or someone else could answer as people here sound like they are familiar with this battery.

Does this battery have a relatively reliable battery management system to protect it from over discharge? If I very occasionally ride it to empty, am I in substantial danger of starting a big fire next time I try to recharge it?

If the battery was damaged by being allowed to get so discharged the bike would not run, would the damage be immediately apparent ? ( Such as on that first 10 mile round trip ) It accepted a full charge and seemed to have plenty of power after this. Am I right to assume the battery was not damaged substantially by being allowed to get so low?

Is this batteries seeming loss of capacity possibly just due to the colder weather? In total I have ridden it about 23 miles.

The tires may also be a bit on the soft side and perhaps this is contributing to the problem. I have a woods valve and getting an adapter when I live in an out of the way location is taking a while.

Should I be concerned about being sold a new lithium ion battery that is over a year old?

I would feel more confident I had purchased a good bike if my battery was only 6 months old.

I have been comforting myself by thinking it may be a good thing the battery was dead when the guy at the store charged it, as from what I read this means the battery was probably sent from the factory at a 40% charge and it gradually lost this. It isn't very hot in this area of the world, so it seems likely the battery has been kept fairly cool and at a low charge. From what I read this probably would result in a 4% to 6% loss of the batteries capacity, over the course of a year. What I am not sure of is how starting with an older battery will affect the batteries performance over the course of two or three years. I don't mind if I have began with a 4 to 6 percent loss, if other than that the battery will work the same as a newer one, but I am a bit disappointed as I will only be using the bike once or twice a week so I am thinking it will be the shelf life of the battery that kills it, not the number of charges.

I don't like to complain, but I am wondering if I should be talking to the people who I bought it from and asking for a newer battery.

Should I be concerned that the battery was over a year old when I bought it, and according to the battery lights it seems to drain so quickly in 3 to 10 degree C weather?

 

[flecc]

Hi Onweels. The battery management system will not be a problem so there's no need to worry about excess discharge or overcharging.

On the age of the battery, if your charge was the first from when the battery was supplied from manufacture the loss of life should not be too severe, though it will have lost some since lithium batteries do age whether used or not.

Taking that into account the range doesn't seem too bad, considering that you haven't found the need to pedal much of the time, leaving the motor to do most of the work, and it seems the hill climbing is acceptable too. It's perfectly normal for wheel-hub-motors to have difficulty on the steepest hills since they are geared for full speed and no change down for hills is possible. Very steep hills mean either a fairly big pedalling input from you or walking as you do.

All batteries suffer from the cold, losing efficiency progressively as the temperature drops, and the performance loss then can be quite marked. For example, cars exported to warm countries are equipped with quite small batteries for starting which sit on a tray that looks too big for the job. That tray becomes useful on those exported to cold countries when they are equipped with much larger capacity batteries to cope with the efficiency loss.

Single figure and negative temperatures are just one of the things you will have to live with I'm afraid. Keeping the battery in the warm indoors does help initially when first setting out, but the cold soon drains the warmth away and experiments with jackets around them don't seem too help much.

I hope this is some help to you.
.

 

[Onweels]

Thanks so much for the information. It does help. I don't know much about ebikes and I was worrying I made a mistake. Now I feel more confident in my impression that the bike will do what I need it to, and the small loss of power due to age of the battery is probably not worth worrying about, assuming it doesn't die from being used a couple times a week before my warranty expires.

Even more puzzling, I just went out into the cold shed and turned the bike on to see what sort of charge the battery has now. It has sat with no additional charging since the previously mentioned 4 mile ride, as I read keeping these batteries in the cold with less than a full charge is supposed to conserve the battery life. With no additional charging it now shows three green lights (full)

With the same charge at the top of the 2 mile ride up the hill the battery showed itself down to one green light (low) ( when I was off the bike and the throttle was off) and two green lights when I went two miles further to get home (fuller) ( also with me off the bike and with no throttle).

Perhaps the solution to the worlds energy needs is sitting in my back shed. A mutant lithium ion battery which charges itself needing nothing but cool temperatures.

Now I know the BMS will protect it from over discharge I will charge it up on a relatively warm day, and ride it to depletion to get an idea of my real range without relying on the green lights. I get the impression they are just showing what mood the battery is in on any given moment.

 

[flecc]

Sorry, I meant to mention that before. Lithium cells chemically tire when being used hard or in difficult conditions, but then when subsequently rested they recover. This can result in the content seeming to magically increase, hence the extra light reappearing. All completely normal. As the battery ages and loses capacity that will tend to happen more frequently.
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[Danny-K]

Decided to pop out at 10:00pm tonight - bloomin' freezing it was. Only 2 miles each way with a fully charged up battery to start the ride with. Normally I get 10 miles before the first light bites the dust. But on setting back just two lights were showing, (a 3 light system), and the bike didn't feel it's chipper self at all, dare I say it? It felt s-l-u-g-g-i-s-h. Got back in just after 11:00pm and the late night news mentioned freezing conditions.

A) If it is a freezing night, then e-bikes are going to be hopeless in deep winter; this will be my first winter e-biking.

B) However, if others point out that they've carried on e-biking through previous winters without concern then it canonly mean that I've got a battery problemo.

 

[flecc]

B) However, if others point out that they've carried on e-biking through previous winters without concern then it canonly mean that I've got a battery problemo.

Not necessarily. It depends on the motor power and usage versus the battery capacity. The person who uses little throttle and puts in plenty of pedal effort may be ok while another who wants the motor to do the most work will suffer.

Though as I said above, all batteries suffer in the cold, as can be seen and heard in winter when motorists sometimes struggle to start their cars first thing in the morning.
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[Kamarin]

Hi flecc,

Do you know; is it the case of the battery working in a cold environment or is it the battery being left in a cold environment? I am looking to buy my first ebike kit (probably the Bionx PL350) and wondered, I will be keeping it in the garage which is integral so not as cold.

So when I use the bike in the cold will the battery diminish as it gets colder or does using it keep it warm?

 

[flecc]

Hi Kamarin. It will lose efficiency as it gets colder, but that is offset to a small extent by the fact that a working battery in itself tends to generate some heat. The position is that rechargeable batteries are not electrical devices, they are chemical devices, converting electrical current into a chemical potential.

Chemical reactions generally require heat to be efficient, hence the near universal Bunsen burners in chemistry labs, and equally chemical reactions themselves usually generate heat, which is why a battery tends to get warm as it charges.

We will always be stuck with inefficiency when cold as long as we use chemical batteries. One day we may have supercapacitors storing electrically and they will be ideal in cold conditions, potentially operating better as the temperature drops. That's probably a long way off though.
.

 

[Onweels]

Today there was a break in the wet weather and at last I got to ride my ebike till it ran out of power.

It was interesting.

I charged up the battery and then went 15 miles before I noticed I was having problems getting up the hills due to a lack of power. It wasn't that the motor actually stopped, it just didn't have the power to assist me on a major hill like it did before, and I ran out of power in my legs.

At the end of 16 miles the bike was still running and helpful on level ground and slight inclines but when I tried to go up a moderate hill that me and the bike easily climbed earlier in the day, I had to stop because pedaling was just too hard.

I was surprised at how it went from having plenty of power to not having enough in one mile.

This ebike doesn't have speeds, just a twist throttle to go. When I am going downhill I just coast, and when I am on a major uphill the bike needs me to help by pedaling , but on level ground and slight uphills it seems easiest just to sit there with the throttle on and let the bike do all the work. If I try and pedal nothing connects because the bike is going faster than I can pedal. As I was testing it's range I was inclined to let the bike do most the work.

I am not in great shape and weigh about 185 lbs. 5 miles of this trip included about 20 lbs of groceries. The route included 5 major hills and 7 big ones and lots of little ones. The temperature was about 10 degrees C.

So I feel the bike and battery are performing as well as I had hoped, and I'm less concerned that the battery was a year old when I got it.

Does this sound like a reasonable range for a new 36 volt 10 amp hour battery under the conditions?

 

[john]

Does this sound like a reasonable range for a new 36 volt 10 amp hour battery under the conditions?

If you are not able to pedal much and you have a number of hills then 16 miles doesn't sound too bad. Hills really take it out of the battery as do a lot of stops and starts.

 

[flecc]

Agreed, that's a very reasonable range with a powerful motor and one of these batteries at that temperature. Batteries of all kinds are severely affected by the cold as you noticed with yours previously in very cold weather, so if the temperature had been 20 degrees C yesterday, you'd probably have done a little better yet.
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[RobNYC]

Temps in NYC have been about freezing lately.

I keep my bike in my apartment overnight while it charges. At work, I must leave my bike in the cold.

I'm guessing it makes sense for me to bring my battery into my office while I work. That way, the battery is warm when I begin my ride home from work and will lose efficiency as it cools down from being outdoors.

Hopefully, I get home before it gets completely cold.

Do I have this right?

One more question, does the battery degrade on a long-term basis from being in the cold?

 

[RedSkywalker]

Just a thought - my Vectra has a jacket fitted round the battery as standard [presumably to keep it insulated from cold air] if they do it for cars why don't they do the same for bike batteries?

 

[flecc]

Yes that's right Rob, you'll gain some advantage from runningthe battery warm initially, though it won't take long for it to get cold again. That process is slowed a bit though by the fact that using it generates a little cell heat anyway.

The cold does no long term damage to a battery as long as it isn't frozen below zero, but that couldn't happen while it's in use.

It would be good to have battery insulation Red, but as ever, manufacturers struggle to make batteries discrete and as small as possible and effective insulation would make them much more bulky and unattractive.
.

 

[RobNYC]

Yes that's right Rob, you'll gain some advantage from runningthe battery warm initially, though it won't take long for it to get cold again. That process is slowed a bit though by the fact that using it generates a little cell heat anyway.

The cold does no long term damage to a battery as long as it isn't frozen below zero, but that couldn't happen while it's in use.

Would you happen to know at which temperature Li ion battery efficiency starts to decline? Is there a point at which the decline accelerates? I'm trying to assess when I should bother to bring the battery inside at work.

 

[flecc]

I think the optimum working range is around 30 degree C (94 F), so a very gradual decline starts below that.

There is no sharp step though, at least until lower single degree temperatures are reached, so under about 8 degrees C (46 F) would probably be a good point to bring it indoors.
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