Another day, another (Powacycle) battery problem

[hannibal]

Powacycle lipo battery for a Salisbury is behaving strangely.

Symptoms:
1) charges up fine, battery charger light changes from red to green, three red lights on the battery when switched on

2) Works fine, initially for about 10 minutes, then cuts out completely - no power and no red lights at all

3) Cycle back home with no battery and plug into charger: three red lights come on straight away (if I switch it on with the key)

This problem has only appeared recently. It started cutting out, then coming back on - then failed completely.

I'm pushing it, as this battery has served me well for nearly 4 years, well beyond the expected life I see discussed on here - but still, it seems like there is some life left in it.

I don't think it can be a fuse problem, as the thing works for a while. Perhaps it is something to do with the BMS - but why would it cut out completely (and fail to recover)? As soon as the charger goes in, it springs back to life. Odd.

Anyone have any ideas? Or is it doomed?

 

[Deleted member 4366]

Most likely cause is a balance wire off. You'll have to open up the battery and check the wires from the cell-groups to the BMS. If you have a voltmeter, you can check the voltage of each cell-group to see which is the offending one. Also before doing that, you should check the battery straight off the charger and then when it cuts out to see what voltage it shows, which will confirm the problem.

 

[hannibal]

Most likely cause is a balance wire off. You'll have to open up the battery and check the wires from the cell-groups to the BMS. If you have a voltmeter, you can check the voltage of each cell-group to see which is the offending one. Also before doing that, you should check the battery straight off the charger and then when it cuts out to see what voltage it shows, which will confirm the problem.

Thanks d8veh

I have already opened it to look for loose connections, moisture etc. but will check the voltages as you suggest.

 

[Del 80]

Hannibal, Would be interesting to know the outcome of your problem, I gotta Powacycle Salisbury as well, which is o.k........at the moment.......Del.

 

[muckymits]

Ive seen something similar a few months ago, even Powacycle are baffled. The poor guy has spent about 1500 quid trying to sort his and his wifes bikes out.

Both bikes bought at same time and both developed fault at same time, goes about 5 miles then cuts out. But the lights are still on, so after 6 batteries, a charger and a controller. I think it might still be running or hes ran them both in to the north sea

 

[Del 80]

I must say that since my charger packed up, and I got this new one, that the battery is performing much better, they reckon that chargers either work, or they don't, they don't get ''weaker'' with age, probably not much use to Hannibal, as his sounds like a battery problem, but worth considering......Del.

 

[hannibal]

Thanks for the comments - this technical help is really one of the great things about this forum!

Yes, sorry for not updating - but I dug out my voltmeter and it promptly fell to bits, so I have just bought a new one (from Wilkos).

Anyway, I took the battery apart again and this time sprayed the key switch with WD40, which is the only moving part. I'll also clean/spray the contacts. All the connections seem to be firmly attached.

I read somewhere that one test of a battery health is to charge it up, then see how long it takes to charge the next day. Both of my batteries took a while to show green on the chargers, so neither of them seem to be in great condition, which is not surprising given their age. (Both over 3 years - I repaired the other one recently by replacing a fuse.)

The problem developed after I left the bike outside for a few hours in the rain, which made me suspect an internal short-circuit due to moisture or possibly rust - but that is just a naive guess.

I'll update if there are any developments.

 

[Deleted member 4366]

It could well be the main battery connection underneath the battery, which loosen off after a bit and need squeezing back together. Still need those voltage readings to find a direction to go.

 

[hannibal]

Follow Up

Sorry for the delay in updating.

The multimeter I bought from Wilkos didn't work, neither did the replacement!

In the meantime I opened up the battery again, jiggled all the wires (which seem to be firmly attached) and sprayed WD40 on the inside of the key switch. Then I charged it up again.

The next day I charged it again, and after a few minutes the green light (on the charger) turned red, indicating that it was not losing charge.

I then took the bike out on a test run, fully expecting it to conk out after 10 minutes. However, it turned out to be fine.

So, it looks like the problem has sorted itself out - but what the original fault was, I'm none the wiser.

Bottom line: have patience with your battery!

Now I have a multimeter (from Maplin, this time) :'ll double check the battery voltage. Fingers crossed that I have a bit more life in it.

 

[morphix]

Great to hear your battery is still working after 4 years! Has it only had light usage and been well looked after, never allowed to run flat? What type of battery chemistry is it out of interest?

My first battery was a LiFePo4 5Ah and it only lasted 9 months before one of the cells died. I think it was over-worked though on hills as I looked after it quite well and it only had moderate usage.

 

[hannibal]

Great to hear your battery is still working after 4 years! Has it only had light usage and been well looked after, never allowed to run flat? What type of battery chemistry is it out of interest?

My first battery was a LiFePo4 5Ah and it only lasted 9 months before one of the cells died. I think it was over-worked though on hills as I looked after it quite well and it only had moderate usage.

Sorry, I'm not sure of the exact chemistry - it is called a Lipo but I'm sure it is not LiFePo4.

I used this daily for commuting, uphill all the way home (but only around 3 miles each way). In the last year and a half, I've used it regularly - including some longer journeys (to the point of running out of juice once).

After reading up on Pedelecs when I bought it, I charged it up every evening, but allowed a couple of 'balancing' discharges over the period.No other TLC - it just sits in the hallway, like a dog with a lead in its mouth!

 

[morphix]

Is Powacycle still going as a brand and company? I used to hear it mentioned a lot a few years back when I first came to the forum now it's gone silent.

 

[hannibal]

Sorry for the delay in updating.

The multimeter I bought from Wilkos didn't work, neither did the replacement!

In the meantime I opened up the battery again, jiggled all the wires (which seem to be firmly attached) and sprayed WD40 on the inside of the key switch. Then I charged it up again.

The next day I charged it again, and after a few minutes the green light (on the charger) turned red, indicating that it was not losing charge.

I then took the bike out on a test run, fully expecting it to conk out after 10 minutes. However, it turned out to be fine.

So, it looks like the problem has sorted itself out - but what the original fault was, I'm none the wiser.

Bottom line: have patience with your battery!

Now I have a multimeter (from Maplin, this time) :'ll double check the battery voltage. Fingers crossed that I have a bit more life in it.

The sun is shining, let's take out the bikes for a little run

....and it failed again, after about 10 minutes (cycling uphill). All the lights out (there are 3 red lights that act as a kind of battery power indicator).

Back home again the battery actually registered a small steady voltage (measured at the output - where the bike prongs connect) when switched on with the key (less than 1V) but no lights on the battery

Plugged it into the charger and immediately tried the key: bingo, 3 red lights but the voltage I measured is unstable and all over the place. from 1 to 18V and changing each time I measure it afresh.

It's all beyond me - so probably looking at shelling out for a new battery!

 

[hannibal]

I guess so - they still have a website and have added a new model.
Electric Bikes - Quality UK Electric Bike Supplier from PowaCycle which has clearance models

But significantly cheaper at ebikes direct.
PowaCycle Salisbury LPX Electric Bike FREE DELIVERY

My Salisbury (which I think is their most popular model) has proven to be quite robust and reliable over 4 years of commuting and off-road exploration trips.

 

[muckymits]

The batteries are about £300 so consider a rack battery. One day I will build a dummy load for these things and attach the celllog then give them a good flogging. My Lipo is an ex one of these and cell 5 is always down when Ive done a run, my money is on the BMS tho.

 

[hannibal]

The sun is shining, let's take out the bikes for a little run

....and it failed again, after about 10 minutes (cycling uphill). All the lights out (there are 3 red lights that act as a kind of battery power indicator).

Back home again the battery actually registered a small steady voltage (measured at the output - where the bike prongs connect) when switched on with the key (less than 1V) but no lights on the battery

Plugged it into the charger and immediately tried the key: bingo, 3 red lights but the voltage I measured is unstable and all over the place. from 1 to 18V and changing each time I measure it afresh.

It's all beyond me - so probably looking at shelling out for a new battery!

The battery is recharged and the voltage is a steady 29V-ish (my previous measurement may have been wrong). I'm guessing the problem may be due to the BMS doing a voltage cut-out and then not being able to recover. Beyond my technical skills - but annoying if the battery cells are still OK.

 

[hannibal]

I should add that it is a nominal 24V battery.