Battery concern

[Stapley13]

i collected a new bike yesterday. It had the wrong battery on. A 375kwh instead of the 575.
Obviously this was inconvenient but my concern was the dealer swapped it for a 575 which was flat.
Not just low on charge but completely depleted. Absolutely zero charge.
The owners manual says never leave the battery completely discharged and that the warranty may be void if you don't care for it.
Am I right to be concerned?

 

[rich_r]

Zero charge according to the meter on it, or zero volts as measured with a voltmeter?

You are correct in that if you allow lithium battery cells to discharge below around 3.3V then then start to suffer permanent damage, so in general they have a battery management circuit on board that won't allow this to happen when in use. So a 36V e-bike battery will generally be 42V when showing fully charged and around 33V will be when it shows empty.

They should be stored at around 50% charge - so about 3.6V per cell (ie 36V total for a 10cell pack) - which is why they are called 36V batteries rather than 42V batteries

 

[Fordulike]

i collected a new bike yesterday. It had the wrong battery on. A 375kwh instead of the 575.
Obviously this was inconvenient but my concern was the dealer swapped it for a 575 which was flat.
Not just low on charge but completely depleted. Absolutely zero charge.
The owners manual says never leave the battery completely discharged and that the warranty may be void if you don't care for it.
Am I right to be concerned?

I suppose it depends on how long the battery has been empty. If it had recently been used down to the BMS cut-off, then it shouldn't be an issue. Charge up and use.

If on the other hand it's been lying around the workshop unused, and allowed to drop over time to that level, then maybe not.

I would be more concerned about the dealer, firstly supplying the wrong battery, then one with zero charge and obviously neglected. Shows incompetence, and I would personally reject the bike, get my money back and go elsewhere.

 

[Stapley13]

Zero charge according to the meter on it, or zero volts as measured with a voltmeter?

You are correct in that if you allow lithium battery cells to discharge below around 3.3V then then start to suffer permanent damage, so in general they have a battery management circuit on board that won't allow this to happen when in use. So a 36V e-bike battery will generally be 42V when showing fully charged and around 33V will be when it shows empty.

They should be stored at around 50% charge - so about 3.6V per cell (ie 36V total for a 10cell pack) - which is why they are called 36V batteries rather than 42V batteries

The battery was flat when connected to bike. The bikes LCD would not turn on. The battery status lights on the battery would not light either.

 

[Fordulike]

The battery was flat when connected to bike. The bikes LCD would not turn on. The battery status lights on the battery would not light either.

I may be wrong, but it sounds like the dealer can't even be arsed to test and supply a working battery. Either kick up a stink or reject.

 

[Nealh]

Personally I would return the battery and ask for a battery with charge, ideally a storage charge of 38-39v, though above 37v will be fine.

Connecting a battery that doesn't even allow the lcd to turn on is not good. Even if the lvc cut off the battery the voltage would recover to allow some power.

A couple of checks need to be made a voltage check from the battery pins and whether the fuse is intact. Some times the few is an internal one and not always within the scope of everyone to look without voiding any warranty. Probability is that you may have been fobbed off with a bad or old battery that has been allowed to discharge to low.

 

[Stapley13]

Update from Wisper support.......

If the battery charged then it is fine.

It did charge and seems fine.

 

[Mal69]

Update from Wisper support.......

If the battery charged then it is fine.

It did charge and seems fine.

I am not convinced, you don't know how many charges that battery supplied has already had, it may now be at a quarter of its life or even less, the dealer seems poor to me, what happens if you need service in the future, I wouldn't trust them from what you have already said.

 

[redcup1999]

Is this a battery which goes into a deep sleep when not used for a period of time in order to protect itself? In such a case, it needs to go through a wake up routine before it will power the bike on regardless of what the voltage of the battery is.

On some batteries I believe that connecting it to the charger will wake it up.

 

[Nealh]

At some stage David will probably come on and explain, If it has the sleep option then the issue isn't serious. Wisper have a good rep on the forum and maybe the dealer needs a little refreshment training on explaining the product he is selling.
Although in the OP no name or make was given the 375 & 575wh should have rung a bell as not many offer these two size of batteries.

 

[Wisper Bikes]

Hi guys sorry I missed this thread.

Claud from Support is correct, if the battery takes and holds a charge then it will be fine. A battery damaged through its being left uncharged will not charge properly.

The deep sleep mode will kick in after 24 hours of inactivity on or off the bike. It does go through a wake up routine when the bike is tuned on. If the LCD didn't come on when the battery was installed and the bike turned on the battery must still have been in deep sleep mode. Even the smallest amount of power would have turned the display on.

I honestly don't think there will be any issues with the battery. However if you are worried, send it back to us and I will happily replace.

When fully charged the voltage should be 41 to 41.5V the sure fire way to check the battery is OK is to check it with a meter.

All the best, David

 

[Stapley13]

At some stage David will probably come on and explain, If it has the sleep option then the issue isn't serious. Wisper have a good rep on the forum and maybe the dealer needs a little refreshment training on explaining the product he is selling.
Although in the OP no name or make was given the 375 & 575wh should have rung a bell as not many offer these two size of batteries.

It does have the sleep mode.

 

[Stapley13]

Thanks for your response David.

The battery has charged ok.

The charge state the battery was in when I recieved did go against the info in the manual and the wisper warranty.

I would send back but the turn around time would mean I would be without a bike for at least a week.

 

[Wisper Bikes]

Do you ever get anywhere near Sevenoaks? I am happy to swap the battery for you at anytime in the next six moths. If you are close by we can do a swap or I could meet you half way at the weekend.

All the best, David

 

[Stapley13]

Could it be swapped at BikeTart in Canterbury city centre please?

 

[Wisper Bikes]

As you didn't buy the bike through Bike Tart I would prefer not to get them involved. Why not do it at Autobase where you bought the bike?

I am also willing to drive down and meet you half way in say Ashford? Or you can wait until next time you are this way.

As I say I am sure the battery is perfect, if you get any problems I will sort it out for you. I think you maybe putting yourself to a lot of trouble for no real gain.

Please let me know what suits you best.

All the best David

 

[Stapley13]

Autobase will be fine.

 

[Fordulike]

Well, you couldn't ask for any better personal service than that Stapley13!

David comes up trumps once again, top man

 

[Wisper Bikes]

Autobase will be fine.

OK no worries, I am pretty sure we will have already sent them a replacement for the 375Wh battery we sent in error. However I will check on Monday.

All the best, David

 

[Stapley13]

Thank you so much.
Will the battery be charged or should I drive there?