Newbie e-biker

[Jillyh]

hello there, I have bought a second hand whisper 705se. Recently I have been going further a field and encountering some steep hills. Unfortunately the motor cuts out half way up these hills and I'm forced to get off and push, then after about ten minutes it will start working again? Is this normal? It's a shame because I love the bike‍ Any advice would be really appreciated .

 

[D C]

If its a few years old it sounds most likely to be a problem with the battery.
Someone with a similar problem posted a few days back.
I'm sure you'll get more expert advice shortly
Dave.

 

[Benjahmin]

It sounds like the battery is going below the low voltage cutout. This is to protect the battery from too low a voltage. By the time you have walked up the hill the battery chemistry has 'caught up' so system can run again. I t possibly indicates that the battery is in a poor state either because it's reaching the end of it's life or needs a bit of tlc.
How old is the bike? Do you know how often it was ridden/ usage pattern?
Give as much info as you can and there'll be help available.
Don't worry Jill, it doesn't sound terminal, the 705 has a good rep.

 

[LeighPing]

Don't worry Jill, it doesn't sound terminal.

Ohm my god. I got it. Boom, boom.

The next person with a battery joke will be placed on a charge!

 

[Deleted member 4366]

Almost certainly, the battery is knackered. If you give jimmy a call at BGA Reworking, he'll sort it for you for about £250. He arranges collection and return.

For anybody else that buys a used bike, you should always work on the basis that it'll need a new battery, except maybe if you can see that the bike is less than 6 months old. In that respect, hardly used doesn't count. the battery can deteriorate by bad storage conditions. Also, some people try to fast charge their batteries, which ruins them, so it can be knackered even when relatively new. Worse still, you never know if the owner or his/her family or friends don't have two bikes: One is well-used and the other hardly used. they swap batteries before selling the hardly used one. There's so many possibilities for unscrupulous sellers.

 

[Jillyh]

It sounds like the battery is going below the low voltage cutout. This is to protect the battery from too low a voltage. By the time you have walked up the hill the battery chemistry has 'caught up' so system can run again. I t possibly indicates that the battery is in a poor state either because it's reaching the end of it's life or needs a bit of tlc.
How old is the bike? Do you know how often it was ridden/ usage pattern?
Give as much info as you can and there'll be help available.
Don't worry Jill, it doesn't sound terminal, the 705 has a good rep.

 

[Jillyh]

Thanks for all the advice, the bike is roughly two years old and in total has been ridden approx 5 hours in total. The rest of the time the battery has been left in the bike!

 

[Benjahmin]

Thanks for all the advice, the bike is roughly two years old and in total has been ridden approx 5 hours in total. The rest of the time the battery has been left in the bike!

That could be it then. Batteries don't like being left.
Give this a go. Use the bike and charge as usual. However leave the charger on for a couple of hours after it has apparently finished charging. This is to allow the battery management system (BMS) to balance the individual cells in the battery. Do this 3 or 4 times. It may work and give your battery a further lease of life.

 

[Jillyh]

That could be it then. Batteries don't like being left.
Give this a go. Use the bike and charge as usual. However leave the charger on for a couple of hours after it has apparently finished charging. This is to allow the battery management system (BMS) to balance the individual cells in the battery. Do this 3 or 4 times. It may work and give your battery a further lease of life.

 

[Jillyh]

Thank you

 

[Deleted member 4366]

2 hours isn't long enough. You need to leave ot on the charger for about 24 hours after it's gone green. If there's any improvement, leave it on charge for a couple of hours every time you charge it thereafter for the next 10 charges or so.