Pendleton Somerby Battery Problems

[plymouthpirate]

Hello,

hoping someone can give some advice. My wife has a Pendleton Somerby electric bike which she hasn’t used for quite some time. When I tried to charge the battery yesterday I found that It wouldn’t take a charge at all. It’s very upsetting because she has hardly used the bike. I measured the voltage output of the battery and it’s coming out at about 3V. Reading online I suspect that one or more of the cells has too low a charge and the BMS is refusing to charge it.

Can anyone recommend somewhere that can undertake a diagnosis/refurbishment of the battery please at a reasonable price? Unfortunately the bike is out of warranty now. If not, I’m even open to having a go repairing it myself assuming it’s fairly straightforward like replacing some of the cells. A YouTube video or such like would be helpful if someone knows of one.

Many thanks

 

[vfr400]

Hello,

hoping someone can give some advice. My wife has a Pendleton Somerby electric bike which she hasn’t used for quite some time. When I tried to charge the battery yesterday I found that It wouldn’t take a charge at all. It’s very upsetting because she has hardly used the bike. I measured the voltage output of the battery and it’s coming out at about 3V. Reading online I suspect that one or more of the cells has too low a charge and the BMS is refusing to charge it.

Can anyone recommend somewhere that can undertake a diagnosis/refurbishment of the battery please at a reasonable price? Unfortunately the bike is out of warranty now. If not, I’m even open to having a go repairing it myself assuming it’s fairly straightforward like replacing some of the cells. A YouTube video or such like would be helpful if someone knows of one.

Many thanks

It might have gone to sleep. Try holding the on button for a very long time to see if it wakes up.

 

[plymouthpirate]

It might have gone to sleep. Try holding the on button for a very long time to see if it wakes up.

Just tried that. Held power button for over a minute. Nothing unfortunately.

 

[mike killay]

info@ebikebatteries.co.uk
They are really good

 

[plymouthpirate]

info@ebikebatteries.co.uk
They are really good

Ok thanks very much. Any idea about ballpark cost for a refurbishment?

 

[vfr400]

Ok thanks very much. Any idea about ballpark cost for a refurbishment?

It depends what cells you choose. You can have long life, high capacity, low cost, high discharge rate, etc. A like for like replacement would probably be about £200. You need to ring them up and discuss the options.

 

[plymouthpirate]

It depends what cells you choose. You can have long life, high capacity, low cost, high discharge rate, etc. A like for like replacement would probably be about £200. You need to ring them up and discuss the options.

Ok thanks for the info

 

[Nealh]

One can if it is easy to do so open the battery and take 10 voltage readings via the BMS connector this will tell us if the battery is able to be recovered or whether it needs re-celling, replacing individual cells isn't really cost affective as any new cells will be working harder to carry the older cells.
If it can be opened and the cell pack withdrawn or at least access to the BMS we can guide you to taking the readings.

 

[plymouthpirate]

One can if it is easy to do so open the battery and take 10 voltage readings via the BMS connector this will tell us if the battery is able to be recovered or whether it needs re-celling, replacing individual cells isn't really cost affective as any new cells will be working harder to carry the older cells.
If it can be opened and the cell pack withdrawn or at least access to the BMS we can guide you to taking the readings.

I measured the voltage output of the whole battery from the external connector. This was about 3V. I’m guessing this means that no individual cell is more than that. Is it possible to recover a cell then?

 

[Andy-Mat]

Hello,

hoping someone can give some advice. My wife has a Pendleton Somerby electric bike which she hasn’t used for quite some time. When I tried to charge the battery yesterday I found that It wouldn’t take a charge at all. It’s very upsetting because she has hardly used the bike. I measured the voltage output of the battery and it’s coming out at about 3V. Reading online I suspect that one or more of the cells has too low a charge and the BMS is refusing to charge it.

Can anyone recommend somewhere that can undertake a diagnosis/refurbishment of the battery please at a reasonable price? Unfortunately the bike is out of warranty now. If not, I’m even open to having a go repairing it myself assuming it’s fairly straightforward like replacing some of the cells. A YouTube video or such like would be helpful if someone knows of one.

Many thanks

Assuming that you get a new or re-celled battery soon, please do not simply "ignore" it when not using the bike.
These Li-ion batteries do need some very simple (I will call it) "maintenance", to keep them working over long periods. Others here have mentioned, and I fully agree with them, that 6+ years is easily attainable, with a bit of care.
When you have your battery fixed, come back and ask us, though some here will never agree with others here!
That's life!
But we will all try to help you.
regards
Andy

 

[vfr400]

I measured the voltage output of the whole battery from the external connector. This was about 3V. I’m guessing this means that no individual cell is more than that. Is it possible to recover a cell then?

If 3v is a true reading, it means that the management system has shut the battery down. That management sytem includes the switch. When any 36v lithium battery goes down to 29v, it gets shut down by the management system. Actually, there are 10 cell groups in the battery. When any one goes down to 2.9v, the battery will be shut off until it's recharged, and when any go below 2.5v, charging will be shut off too. With all that in mind, it's impossible to get an output of 3v. It has to be 0v or something above 29v, but what you can measure is leakage charge when the battery is shut down. The value you get depends on the impedence of your meter. Around 10v to 18v is normal, but it not a real voltage. If you connected a load, it would immediately collapse to zero.

3v is a bit unusual, though feasible. We had an instance a few days ago where a guy was measuring 2v when the reading should have been 0v. It turned out that his meter was faulty. When the battery runs out in the meter, the readings drift up, so you should check that it's reading correctly. If your actual voltage turns out to be 0v, then the cause is more likely to be a blown fuse or faulty connection.

 

[plymouthpirate]

Assuming that you get a new or re-celled battery soon, please do not simply "ignore" it when not using the bike.
These Li-ion batteries do need some very simple (I will call it) "maintenance", to keep them working over long periods. Others here have mentioned, and I fully agree with them, that 6+ years is easily attainable, with a bit of care.
When you have your battery fixed, come back and ask us, though some here will never agree with others here!
That's life!
But we will all try to help you.
regards
Andy

I’m unlikely to “ignore it” as you put it if it ends up costing £200+ to replace/re-cell it. I think that lesson has been learned.

Nealh has suggested that if I can get the cover off the battery I should be able to determine if the battery can be recovered. Before I attempt that, can someone tell me what is involved in ‘recovering’ the battery. I’m assuming that means recharging the individual cells to a level that the BMS will allow normal charging again? Does ‘recovering’ the battery require any specialised equipment? I’m just trying to understand if this worth attempting at this stage. Thanks very much.

 

[Andy-Mat]

I’m unlikely to “ignore it” as you put it if it ends up costing £200+ to replace/re-cell it. I think that lesson has been learned.

Nealh has suggested that if I can get the cover off the battery I should be able to determine if the battery can be recovered. Before I attempt that, can someone tell me what is involved in ‘recovering’ the battery. I’m assuming that means recharging the individual cells to a level that the BMS will allow normal charging again? Does ‘recovering’ the battery require any specialised equipment? I’m just trying to understand if this worth attempting at this stage. Thanks very much.

Firstly, if you are not a DIYer with a lot of "know-how" in this area, you should not try to do it yourself. There is so much energy in a battery of this type, if it catches fire, they are as good as impossible to put out, unless you have a handy pond in the garden to throw it into. Where it will kill all the life in that pond as the gases are noxious.
German police use a huge tank full of water to extinguish e-cars that have caught fire. It can take several hours for a car battery to stop burning, even under water.
Just to inform you, look what happened to this Dutchman's e-bike, when he did something wrong with his battery (Guessing only, he added a second battery with no BMS between them, as there is one on the rack, and one on the down tube):-

It is a good idea, if no pond is handy, to slow the reaction down as much as possible with water, to stop cells exploding with huge force, but they still make a strong "thud" as the next one is torn asunder.
Bike batteries should not be stored in a house.
But do keep away from the fumes, they are poisonous.
Andy

 

[vfr400]

I’m unlikely to “ignore it” as you put it if it ends up costing £200+ to replace/re-cell it. I think that lesson has been learned.

Nealh has suggested that if I can get the cover off the battery I should be able to determine if the battery can be recovered. Before I attempt that, can someone tell me what is involved in ‘recovering’ the battery. I’m assuming that means recharging the individual cells to a level that the BMS will allow normal charging again? Does ‘recovering’ the battery require any specialised equipment? I’m just trying to understand if this worth attempting at this stage. Thanks very much.

First step is to open the battery case. Inside are wires, a cell-pack and a management module (BMS). The BMS is connected by some wires, one of which is nrmally a ribbon cable that goes to a multi-pin connector. That ribbon cable is all the wires from the top of each cell group. You unplug the connector, then you can measure the cell voltages on it. That will give you a good idea about the condition of the battery before you decide what next steps to take.

 

[Nealh]

As vfr and I have indicated access the BMS ribbon connector first and disconnect it ( the connector is white and will have 10 or 11 thin sense wires attached).
When you have reached this stage we can guide you to take the necessary 10 cell group voltages via the ribbon/sense wire connector.
For your meter test it by measuring any other type of battery to make sure it is reading correct otherwise simply put a new battery in it so no erroneous readings are given.

I had a forum user bring to me a battery recently it takes longer to undo and remove the internal battery pack then it does to take the voltage readings. The silverfish one I looked at had silicone applied both ends so it needed carefully removing before the pack could be slid out.

 

[Andy-Mat]

I’m unlikely to “ignore it” as you put it if it ends up costing £200+ to replace/re-cell it. I think that lesson has been learned.

Nealh has suggested that if I can get the cover off the battery I should be able to determine if the battery can be recovered. Before I attempt that, can someone tell me what is involved in ‘recovering’ the battery. I’m assuming that means recharging the individual cells to a level that the BMS will allow normal charging again? Does ‘recovering’ the battery require any specialised equipment? I’m just trying to understand if this worth attempting at this stage. Thanks very much.

We will see what happens.
The reason that many batteries fail is because the have not been actively maintained for a long time.
Long can be a month, 3 months, or even longer.
Its often an expensive mistake.
Best wishes for a good outcome!
Andy

 

[Nealh]

I have various Lion & Lipo batteries/packs 3s, 7s, 10, & 13s which sometimes don't get used for months and they remain in good condition, the storage conditions and voltages are the important factor as is the checking the voltage of them every now and then.

 

[Nealh]

I measured the voltage output of the whole battery from the external connector. This was about 3V. I’m guessing this means that no individual cell is more than that. Is it possible to recover a cell then?

Cells/cell groups can be recovered depending on the voltage reading, any cell/group voltage down to 2.5v should be recoverable. The means to recover individually depends if the user has the patience to do so, this can be discussed once the voltages are known.

 

[vfr400]

I have various Lion & Lipo batteries/packs 3s, 7s, 10, & 13s which sometimes don't get used for months and they remain in good condition, the storage conditions and voltages are the important factor as is the checking the voltage of them every now and then.

The battery on my bike was stored for two years without use before I fitted it. I bought it for another project, but then changed my mind about it, so it just sat in my bedroom unwanted for all that time. I have a battery that I use for testing that hasn't been charged for 5 years. It's still sitting at 39.5V (LiFePO4).

 

[Andy-Mat]

I checked and LiFePO4, though sounding similar to Li-ion, are far more robust and stable.
I read:- " LiFePO4 batteries are best known for their strong safety profile, the result of extremely stable chemistry. "
I was talking previously about Li-ion.....which do need active maintenance to keep running as they should....Sorry!
Andy