Unanswered Can a faulty charger or bike kill a battery?

[Eljay]

I have had 2 700 watt Specialized Levo batteries (I have always had 2 for big rides and trips) fail back to back within 1 week of each other and they were both showing high 90% health have less than 100 cycles each. It just seems like too much of a coincidence and, other than really bad luck, the only things I can think of is that possibly there is something wrong with the charger or bike that killed these batteries since I was using the same charger and bike w/ both of them. Does this make any sense or is it more likely just plain bad luck?

 

[Mabman]

That is an expensive proposition to replace...hard to figure out though how both batteries failed at the same time? You say they were @ 90% health with less than 100 charges but what does the app say now about them that makes you think they are both dead?

 

[Eljay]

When I plug either of the batteries in to charge, only the 2nd light blinks, which is the error code for a failure. The bike does not turn on at all so cannot look at app with either battery installed, but it does turn on with a friends battery.

 

[michael.kozera]

batteries all have built in BMS. so unlikely that the bike and or charger killed them. sounds to me like coincidence. however if a 3rd battery dies. then yes. something up with bike or charger. I would be suspect of charger power spikes, voltage spikes, communications errors, balance issues.

 

[Aussie78]

No way that’s bad luck.

Something is faulty, and it’s a rather odd issue.

The BMS is monitoring charger incoming voltage, if it’s above tolerance, which is probably 42.5 to 43.0volts, it’s terminating the charge cycle.

Likewise the bms is monitoring output voltage, and current. If the pack drops below voltage threshold, the output of the pack is disconnected and the motor is off to protect the cells from under voltage conditions. Same if output current goes too high, the BMS turns off the output, and if output goes drastically over current, the microprocessor on the BMS blows the chem fuse. The chem fuse is a solid state controlled fuse in series with the packs output, when the microprocessor on the bms observes output current of the pack at 5-10 times expected output, it applies voltage to the Chem fuse control line, and in a few ms the fuse goes open circuit, preventing a fire or other catastrophic event.

 

[Mabman]

The other question is did you go for an extended time without using the batteries? If let to run below their low voltage threshold while not in use set by the BMS they will "go to sleep" and may be able to be "woken" back up by someone that is savvy about batteries? I just shudder at the replacement cost you face.....here in the US I think those batteries are like $1400 each?

 

[Mikerb]

Have you tried using a different charger? Have you added or modified anything connected to the bikes electrical circuit? Are you charging both batteries in the bike or outside?
The above questions are an attempt to narrow down potential causes. If none apply, the only common denominator is the charger. The most vulnerable part of both charger and batteries is the rosenberger connectors especially if they are not covered when not in use. Check them for foreign bodies or seized pins.

 

[Alexbn921]

100 cycles and 90% seems like you are not managing your batteries. Was it hot when you charged them or where they fresh off a hard ride with zero charge?

My charger would get over 155f while charging so I added a heatsink and not it stays around 120f.

 

[Eljay]

Thanks for all of the great responses; I am impressed at the knowledge here, but will admit I don't fully understand some of this technical stuff.

Regarding the health of the batteries, I wrote "high 90%" which I realize was confusing - they were not 90% health, but both closer to 98-99% and the reason I did not write the exact amount is that I can't connect to verify the exact % but was basing this off the latest % I saw before they died. I charge the batteries inside a garage and I live in San Francisco in a very mild climate and I alternate between charging in and out of bike.

@Mabman did bring up a great point that I failed to mention and now seems very relevant which is that because of my wife having some health issues they did sit unused for a few months but they are pretty much never drained to totally empty and I pretty much always charge them right after the ride. I will admit to forgetting about them being plugged in sometimes for several days which I know isn't ideal, but almost everybody I know does this. I will be borrowing a friends charger to see if it works on them and of course taking them into a shop to see what they say, but they have already told me on the phone that they cannot be repaired. Painful!

I guess the ultimate question is does anybody know of a 3rd party that will repair these these if it comes to that? Thanks!

 

[Alexbn921]

A lot of these batteries have a kill mode built into the BMS. Basically as soon as the BMS doesn't see the cells it bricks itself and never works again. Very anti right to repair.

 

[Mabman]

On the other hand a friend of mine and his wife that split time between the EU and the US have a couple of Levo's stashed in a locker along with their other gear. During Covid they didn't get over there for almost 2 yrs. and upon getting the bikes out of storage, where nothing was done about the batteries during that time, they both worked and took a charge. I just mentioned it because it can happen that a battery will bleed below the LVC which essentially bricks it as mentioned. So perhaps as you suggest in your first post it is down to bad luck.....

 

[Eljay]

Very anti right to repair.

Out of curiosity, what exactly does this mean? That Specialized does not like to give outside parties the ability to repair batteries?

 

[Mikerb]

Lots of ideas but for me 2 batteries suffering the same problem almost at the same time is too much of a coincidence and the problem could still be something as simple as a faulty charger or a charger with the rosenberger plug contaminated with a piece of something metallic.

 

[michael.kozera]

100 cycles and 90% seems like you are not managing your batteries. Was it hot when you charged them or where they fresh off a hard ride with zero charge?

this is true, 100 cycles and 90% is suspect. like ive had some batteries now for well over 1,000 cycles and still charging 95%+ of its original capacity.

 

[Eljay]

this is true, 100 cycles and 90% is suspect. like ive had some batteries now for well over 1,000 cycles and still charging 95%+ of its original capacity.

You may have missed this in my lengthy reply above:

“Regarding the health of the batteries, I wrote "high 90%" which I realize was confusing - they were not 90% health, but both closer to 98-99% and the reason I did not write the exact amount is that I can't connect to verify the exact % but was basing this off the latest % I saw before they died.”

 

[All4Fun]

I read that the battery is using the magnetic Rosenberg connector, if so, check and clean those connectors good, male and female.
My bike uses these too and i have very often errors because of dirt on the 4 small contact pins, sometimes barely visible.
I guess that is the downside of using multiple batteries, the connectors can pick up dirt more easily.
Results of not seeing the battery at all, displaying an error and shutdown or during biking shutdown, now i give them a quick clean before installing the battery, that helps a lot.

 

[Kiteboy]

I had an issue where I would connect the charger to the battery before plugging it into the wall socket. The plug at the battery would arc every time. Got wise: switched off BMS, plugged into wall socket first to give a solid return path for ground. No more arcing. I also switch BMS off before removing battery from bike or before re-inserting it.

 

[MountainBoy]

Thanks for all of the great responses; I am impressed at the knowledge here, but will admit I don't fully understand some of this technical stuff.

Regarding the health of the batteries, I wrote "high 90%" which I realize was confusing - they were not 90% health, but both closer to 98-99% and the reason I did not write the exact amount is that I can't connect to verify the exact % but was basing this off the latest % I saw before they died. I charge the batteries inside a garage and I live in San Francisco in a very mild climate and I alternate between charging in and out of bike.

@Mabman did bring up a great point that I failed to mention and now seems very relevant which is that because of my wife having some health issues they did sit unused for a few months but they are pretty much never drained to totally empty and I pretty much always charge them right after the ride. I will admit to forgetting about them being plugged in sometimes for several days which I know isn't ideal, but almost everybody I know does this. I will be borrowing a friends charger to see if it works on them and of course taking them into a shop to see what they say, but they have already told me on the phone that they cannot be repaired. Painful!

I guess the ultimate question is does anybody know of a 3rd party that will repair these these if it comes to that? Thanks!

It's highly unlikely your batteries need replacement. My money is on a failed charger. Replace that and I bet you are good to go. Hopefully, it's still under warranty.

If the batteries, against all odds, both failed, I would not recommend third party repair unless you are willing to risk your house and all worldly possessions inside. Aren't they still under warranty?

 

[Eljay]

Well after a lot of back and forth and investigation, I have 2 very expensive bricked batteries that have not been used that much and according to Specialized cannot be repaired. I spoke with a nice rep from Spesh who basically said (simple version at least) that it is very likely that somehow the batteries overheated when charging and the BMS shut everything down as a safety precaution and they are now very expensive paperweights. He said several things could have caused this, but after going through the possibilities the most likely is that a small piece of metal got lodged into the charger plug that interfaces with the battery, causing a short and frying both batteries when they were plugged in to charge. This is a very expensive lesson to be very careful about keeping those magnetic things spotless clean.

Spesh is going to give me an ok discount on new batteries but it's still going to be very painful. Even with the discounts, I still have to pay tax and pay the Specialized bike shop a lot of money just to go through the whole procedure (diagnostics, ordering the battery, etc.), so this will probably end up costing me well over $2K - I could save hundreds if they would just allow me to do it myself directly - probably 15 minutes of work. Also, I now have 2 worthless 700W that probably work fine if they could be repaired. It's too bad there is not a 3rd party vendor who can repair these. I'm not thrilled.

 

[Mikerb]

You have not mentioned whether the charger works. It must be worth getting that checked out before using it on any other battery.
Good practise with the charger is to find a cap to fit over the magnetic rosenberger plug whenever it is not in use. I used the red cap you find on the small camping stove butane gas bottles.

 

[Eljay]

You have not mentioned whether the charger works. It must be worth getting that checked out before using it on any other battery.
Good practise with the charger is to find a cap to fit over the magnetic rosenberger plug whenever it is not in use. I used the red cap you find on the small camping stove butane gas bottles.

I borrowed a charger from a buddy who has an extra one to see if either battery would respond differently to a different charger - unfortunately it didn't - I thoroughly cleaned the plug on mine and will probably do it again several times since I'm scared to use my charger - when I get the new batteries I will monitor very carefully the 1st few times I charge them.

That is a great idea to use a cap over the plug - I'm going to steal your idea of using the gas bottle caps - with stakes this high you'd think they would come with caps.

Thanks again for the input

 

[Mikerb]

I borrowed a charger from a buddy who has an extra one to see if either battery would respond differently to a different charger - unfortunately it didn't - I thoroughly cleaned the plug on mine and will probably do it again several times since I'm scared to use my charger - when I get the new batteries I will monitor very carefully the 1st few times I charge them.

That is a great idea to use a cap over the plug - I'm going to steal your idea of using the gas bottle caps - with stakes this high you'd think they would come with caps.

Thanks again for the input

...you will find the fit a little loose. I used a thin piece of lint free cloth laid over the face of the plug then the red cap pushed over that. It is then a nice firm fit....the cloth picks up any dirt and can be swopped out now and then.

 

[MountainBoy]

Well after a lot of back and forth and investigation, I have 2 very expensive bricked batteries that have not been used that much and according to Specialized cannot be repaired. I spoke with a nice rep from Spesh who basically said (simple version at least) that it is very likely that somehow the batteries overheated when charging and the BMS shut everything down as a safety precaution and they are now very expensive paperweights. He said several things could have caused this, but after going through the possibilities the most likely is that a small piece of metal got lodged into the charger plug that interfaces with the battery, causing a short and frying both batteries when they were plugged in to charge. This is a very expensive lesson to be very careful about keeping those magnetic things spotless clean.

Spesh is going to give me an ok discount on new batteries but it's still going to be very painful. Even with the discounts, I still have to pay tax and pay the Specialized bike shop a lot of money just to go through the whole procedure (diagnostics, ordering the battery, etc.), so this will probably end up costing me well over $2K - I could save hundreds if they would just allow me to do it myself directly - probably 15 minutes of work. Also, I now have 2 worthless 700W that probably work fine if they could be repaired. It's too bad there is not a 3rd party vendor who can repair these. I'm not thrilled.

That explanation (that the battery over-heated when charging and the BMS shut everything down as a safety precaution, leaving you with two bricked batteries). The BMS has very accurate and frequent measurement of the battery temperature during charging and would not let the temperature get high enough to damage anything.

In any case, why are the batteries not under warranty?

 

[Kiteboy]

You might look at the simplest possible causes: Perhaps a piece of conductive material got lodged in the charge socket of charger or battery causing a short and shutting down the BMS, or possibly an arc damaged the charge socket causing it to not fully engage and therefore not charge.

After that you might disassemble one of them and test each cell for proper voltage. If they check out, perhaps install a new BMS.
Just throwing darts here...

 

[Kiteboy]

they dont sell the bms none of them do and they use can bus programming so a normal bms will not work.

you cant even recell these things as if you cut power to the bms it bricks it.

Ah, man... sorry to hear

 

[Alexbn921]

Sucks man.
I have a magnet mounted on the wall by my charger and hang it from that so it's not on the floor. I also have a heat sink on the charger to keep the temperature down.
What are you going to do with the old batteries? I would like to play with them just so I can share what's inside and maybe repair them.

I'm over in walnut creek.

 

[Eljay]

That explanation (that the battery over-heated when charging and the BMS shut everything down as a safety precaution, leaving you with two bricked batteries). The BMS has very accurate and frequent measurement of the battery temperature during charging and would not let the temperature get high enough to damage anything.

In any case, why are the batteries not under warranty?

While the bikes are covered for 4 years, the batteries are only 2 and both batteries are just over 2 years old

 

[Rusty]

How are you charging them - on or off the bike?

 

[MountainBoy]

While the bikes are covered for 4 years, the batteries are only 2 and both batteries are just over 2 years old

Wow! That's a shorter warranty than I would have imagined. Especially considering that the Tesla battery warranty is for 8 years!

 

[Aussie78]

Wow! That's a shorter warranty than I would have imagined. Especially considering that the Tesla warranty is for 8 years!

One has a good handle on the engineering challenges around lithium batteries, in a big part due to entering the market with clear goals from the get go. The other has stumbled in by accident, outsourced everything to the lowest bidder, in a marketplace going through a metamorphosis. Going to be many more victims along the way.