death of an alien?

[stevieb]

after just over 1 year of commuting 2.5 k miles my alien battery appears to be on its way out sadly.
i would have thought it would have lasted a bit longer.
the strange thing is that it has happened so quickly.
up until a week ago i could commute 13 miles and then back without a recharge or the battery indicator showing any loss of segments [i know they are not that accurate]
then on my second last ride the battery level started to decline the moment i left work for the return journey and expired a few miles from home.
this has never happened before.
then on my last commute i noticed the battery level had dropped one segment on my way to work.
fortunateley i had my charger with me just in case.
so i charged the battey at work [not always possible].
my final return journey on a fully charged battery saw it loose 2 segments on the return journey.
i should add that until recently the bike has been used regularly kept indoors and charged when returning home.
in the last week i have had to put the bike in the garage , but always kept the battery indoors and charged as normal .
could the bike itself being stored at lower temp. possibly affect performance?

any advice or suggestions would be great

 

[Deleted member 4366]

It's impossible to say what has caused your battery to decline, but I doubt that you could have done anything to prevent it. We've had a lot of stories of premature failure on their batteries. I would say that it's now time to get a new one. Get a nice downtube one, which will make your bike handle better. Which Alien bike is it?

 

[stevieb]

thanks for that
when you say that :you have had a lot of stories of premature wear on their batteries: do you mean alien inparticular?
it is an alien kit that i fitted to my bike which is 250 watt and i think 10ahr battery rear rack mounted and front wheel drive.
it has performed faultlessly up untill now.
i am in 2 minds about getting a new battery as i hope to be using my oxygen for most of the longer journeys and my kit bike for local stuff.
or is it a case that my battery is on its way out and will very soon be totally useless for even shorter journeys?
if this is the case i would agree with your advice on getting a nice downtube one .
with this in mind can you recommend a supplier and is it an easy conversion from the rack mounted battery?
thanks

 

[stevieb]

update
i have had the battery on charge and decided to leave it a bit longer after the green light came on.
what i noticed was the green light turned red momentarily approximatley every 15 to 20 seconds.
to be honest i couldn,t say for sure if it has always done this because in the past i just swiched off the charger when i saw the green light was on.
after reading some posts on this site could this mean there is some form of inbalance of the cells?

 

[flecc]

That can be the battery's BMS switching on the charge again to achieve a balanced charge in all cells, but doing this with such frequency could mean some cells failing to retain the charge, meaning the battery is near the end. My guess is that it isn't going to last much longer. It isn't only Alien batteries that can fail early on occasions, it can happen on any make, though less commonly on some makes of the highest quality and most expensive batteries.

d8veh will know better than me the best alternative battery options and can give a second opinion on your present Alien battery.
.

 

[Deleted member 4366]

It would be worth leaving it on charge for a long time (at least 12 hours) to see if it gets any better in case it's gone out of balance.

The problems I mentioned were specifically on Alien batteries - mostly the Aurora. Aĺ the ones I've seen had Phylion cells in, which seem to give up a bit more easily than other types, and are less likely to be recoverable.

See what happens first. We can discuss alternative batteries later.

 

[stevieb]

thanks for the replies .
will put battery on a long charge.

 

[stevieb]

so battery has now been on charge for more than 24hours after the green light came on.
not much difference with time in between the red light comming on, maybe a couple of seconds.
the charger is still slightly warm so i assume it,s trying to do something but failing.
the charger would go green then cool down completely in the past.
a test ride is next but i,m not confident ,but will post with the results.

 

[flecc]

Yes, looking ominously like it's as I suspected, one or more cells failing to hold charge.
.

 

[stevieb]

just back fro a 15mile ride and no better.
2 bars down on the display when under load which would not have happened before.
the bike still ran fine getting me home .
will the new range be about this or will it steady [ or rapidly] decline until it has no range at all?
if it will do 15miles i suppose i could live with that because of my other bike.
if not i will probably replace it but not with anything too extravagent because it will be my second back up bike.
any suggestions welcome
ta

 

[trex]

you need to establish first where the problem is. Get a £10 mains electricity meter.
http://www.ebay.co.uk/itm/New-Power-Energy-Meter-Watt-Volt-Meter-LCD-Monitor-KWH-Electricity-Plug-in-style-/121145714430
Charge your battery to full then ride 5 miles. Then connect the watt meter to your charger and charge your battery to full again. If the power consumed is more than 100WH then your motor is suspect, if less then your battery is suspect.

 

[stevieb]

that looks an interesting device so i have ordered one to help diagnose my problem.
it will may also help me demonstrate to certain members of my family how much power is consumed when things are left switched on

 

[stevieb]

ok so i have charged my battery fully, done 5 miles and connected the watt meter to the charger.
after fully recharging [ or what passes for fully recharging] the reading is 0.102 kwh.
so can i assume from what trex has said that it is the motor that is suspect ?
the bike ran normaly for the 5miles
the charger still does the red light on momentarlily though.

 

[flecc]

I think that's too marginal a result, right in the middle of Trex's indications. My opinion is still that the battery is probably the problem, the normal running of the motor supporting that.

I would have been more interested in the total number of miles that the charged battery would run before empty.
.

 

[Deleted member 4366]

That doesn't prove anything about the motor other than it's working normally. I'm not sure why he asked you to do that. You'd be better off with a R/C wattmeter to measure how much electricity comes out of the battery.

 

[stevieb]

ah well at least it didn,t cost much
i wish i understood the reason for this test also but i don,t so just did as suggested.
the battery will be empty after 20 miles and would have lasted 40 miles when new.
i know that the lcd bar display is not that accurate but i could have done my commute to work and back again [26 miles ] and the battery would still show full and have no real decrease in performance now it won,t get me home unless i charge it at work.

 

[flecc]

To me all the indications are that battery age and possibly cell failure is most likely to be the problem. The best batteries and systems usually suffer very little capacity decline at that age, but earlier failures on low and moderate priced ones are not uncommon.

The rapidity of the decline that you reported in your original post can occur when a cell starts to fail, and if that is the cause, the range is likely to continue to decline. My post at number 5 in this thread made the point that a cell was possibly failing to hold it's charge, making the BMS switch on and off as it tried to maintain the cell charge and giving the regularly changing red/green on the charger.
.

 

[trex]

102WH for 5 miles is just too close to call. I was hoping for something like 120WH or 80WH. If the consumption has suddenly risen, your motor is no longer as efficient as it once was. Replacing the motor would have fixed the problem. I would carry on using the motor for and keep watching the electricity consumption. If it remains the same, then you have to carry out a test on the battery. Run the bike for 12 miles, the battery would be fairly empty by then. Plug the charger via the electricity meter. You want to see power used in the region of 83W to 93W for at least 2 and 1/4 hours.

 

[stevieb]

i will continue to monitor as suggested , but what flecc says makes sense

 

[stevieb]

update on the testing.
i have completed 12 miles and recharged the battery.
this produced the following results.
after 3 hours 25 mins consumption was 0.270 kwh.
red led on charger would come on for about 1 second every 10 seconds.
when the green led was on current drawn was 0.04 amps.
when the red led was on current drawn momenteraly rose to 0.590 amps.
the bike ran fine throughout the ride and showed the same reduction in battery on the lcd display as the last time.
i don,t know how to interperate this info but if things are linear then this matches up with the 5miles test because i have used just over twice as much power to recharge for just over twice the distance.
this bike is getting an easier life now so i,m not going to rush out and buy a new battery ,but any suggestions for a replacement and prices would be great so that i can work out when it,s worth while getting one .
thanks