Puzzling battery issues with a Luna Wolf battery pack

audacibus

100 µW
Joined
Sep 25, 2021
Messages
9
First of all, hi to everyone, I just registered here.

About myself I just clocked a year working for Vene Rides, a e-bike and e-kickscooter shop in Miami Beach and I was arguably the best Tech in the area because the others were very bad haha. Happy to help with issues to people around here and do some work if needed.

Having said that, there is a lot that I need to learn and this is one of the issues that I have at hand that puzzles me.

I have a Luna Banana with a Bafang BBSHD and ludicrous controller. This is fitted with a Wolf Pack V1.

I believe the battery to be a 52v, so the charger says.

Battery holds charge and charger, a 52v Luna mini charger works it magic and slowly but steadily charges the battery and it takes a few hours to do so.

Starting with an allegedly fully charged battery and showing this way on display, I can ride about 16 miles and then the display shuts off and is all pedal back home.

This is a too low range.

I have contacted Luna and although they reply pretty quickly, they do not provide much as in way of solutions.

Today I bench tested the Luna and monitored the info closely, as opposed to be on the road and looking at traffic, then bike shuts down and then pedal home which is not a great experience, although it is way better than on a super73.

Bench test shows that the battery goes from stated 100% charge to 76% charge and then dies and cannot be turned on. Motor temperature is reasonable, so this is not an issue of the system shutting itself down or so.

Voltage checked on battery immediately after system shuts down is 29.5v and oscillates a bit up and down.

I do not know how to interpret this apart from that the battery is dying, and if the only solution is to buy another one.

For anyone who knows more than me, please chip in.

Thanks!
 
Voltage and percentage guesstimates of SoC do not relate to state of health.

You need a remaining Ah capacity test, even if only rough.

From 100% Full, down to 3.0Vpc, Constant Current at a very slow rate, over 10 hours (0.1C)

Ideally compared to an identical test performed at commissioning, while breaking the pack in.

14S? how would you not be certain? need to know!

Access to per-cell voltages? need to know!

Verify everything with accurate DMM, DC ammeter, get a coulomb counting wattmeter, basic 101-level tools.

29V on a 14S is criminal abuse of course the pack got murdered if your rig allows that to happen.

So yes it is dead, replace it and learn to better care for the next one if you want it to last longer.
 
audacibus said:
...I was arguably the best Tech in the area.
I'm feeling like you are probably (should be?) more knowledgeable than me, but here goes, forgive me if you already know all what I am able to offer you.

audacibus said:
Wolf Pack V1. ...I believe the battery to be a 52v, so the charger says.
The battery specs should be easily findable.

audacibus said:
Battery holds charge and charger, a 52v Luna mini charger works it magic and slowly but steadily charges the battery and it takes a few hours to do so.

Starting with an allegedly fully charged battery and showing this way on display, I can ride about 16 miles and then the display shuts off and is all pedal back home.
Did you measure the battery voltage after full charge? What was the voltage? Does it hold steady over time after it rests a bit after charging?

audacibus said:
Voltage checked on battery immediately after system shuts down is 29.5v and oscillates a bit up and down.
Where are you measuring from?
29.5V is way below 0% charge for that battery, into the danger zone (below 41-42V).

audacibus said:
I do not know how to interpret this apart from that the battery is dying, and if the only solution is to buy another one.
That battery is fully potted, isn't it? Not simple to repair. But let's verify your voltage measuring processes first.
 
That pack is 14s4p, you are pulling ~30a at full power.
The 30q's (im pretty sure thats what they used in those) can push a good bit of current but i will tell you that if i am pushing it hard i can suck a pack like that dry in 16 miles for certain. Those bikes are going to pull 40wh/mile at higher speeds

As stated, it sounds like your battery was a bit abused. I had one that was defective and the low voltage cutoff was happening at 46v. Went from registering 3/4 life to dead as soon as the battery sagged under throttle. Could be...but if you are riding an HD on a upright mini fatbike hard...def can kill the battery that fast



edit: just saw the part about the ludicrous controller- you definitely need more battery.

Go to the Grin Motor simulator and enter your info- if you scroll down in the motors subcatagory it will have a setting for SHOW ALL that includes the Bafang

Find a similar battery or enter the specs on yours
enter weight, gear tooth count etc. set throttle to auto, scroll to the speed you ride to see your range
 
Thanks for the answers.

Funny in every online forum there seem to be the same arraignment of characters. Nuff said.

Just to clarify a few things: I am at my best mechanically, troubleshooting and reasoning stuff, and at my worst electronically. I do not pose as a specialist in electronics of any kind at all.

Bike was purchased from a client with a broken rotor and some other bike issues, he decided to part with it and I got it for a song. I abused no battery. After fixing the bike and getting back to rolling, I realized that the battery was dodgy.

Opening a motor and changing the rotor are things that I can do very easily and with great attention to detail.

Not sure what abusing a battery means. I admit to swearing at it several times, so perhaps that is what you guys are referring to, lol.

I can do what I know how to do, and what I do not know, I research and ask. That is why I am here for.

john61ct most of your response is incomprehensible, what I understood very clearly is that you are immensely rude.
So, if you are not going to help I do not need your abuse.

99t4 as mentioned above I do not come from an electronics background.
I could not find specs for wolf pack V1.
It seems to hold steady charge.
I am fully charging now and will measure voltage.
When I connect the charger and immediately turn on the display it starts by showing 94% charge.
29.5v is the voltage I get measured from the XT90 connector that goes to the motor. Also from the charging port.
Yes, battery fully potted.

Manbeer I am an old guy and do not ride the bike fast or hard, normally I go 14 mph with a bit of pedal assist, on 5th gear.
This bike comes with history unknown. One outing the motor heated up like hell, I was using it in the highest gear (smaller sprocket), then I did some reading and learned that these motors like to spin a lot. Did not have overheating again.
But battery started deteriorating quickly. First I was able to do 20 miles, then 18, now 16.
Thanks for the suggestion about the Grin simulator - will work on that.
What "more battery" to push a ludicrous would be?

I knew long ago I needed a new battery and that the bike came with this problem, just was delaying the inevitable, I guess.
Any recommendation as to a non-wolf batt that is cheaper in price and with similar quality?

As a side note, Luna's mighty mini display suddenly and without warning started to shed its rubbery bits in a similar fashion to foam upholstery when suddenly disintegrates. As usual Luna does not give you any more help than selling you a new part. In this case I was treated with the "this never happened to anyone" remark. If anyone knows where to find a used or broken one I can cannibalize for the housing, would be grateful.

Thanks
 
Don't know much of anything about Luna's mighty mini display or issues with it. There is a "Items wanted section" that you can post and see if you get any hits or suggestions were to get a used one for parts. Items Wanted

Don't be to offended, there is a lot of first time posters that come on with battery issues. Your case sounds like one of them, no fault of your own. Sounds like some bad cells, the battery will charge up (quicker than it should) to full voltage but the battery has no capacity and it drops of quickly. The display's give an idea of what is going on but not know for accuracy.

Could be another issue, best way to find out follow john61ct post.
by john61ct » Sep 25 2021 11:47pm

Voltage and percentage guesstimates of SoC do not relate to state of health.
The point is to try to figure out if the battery is bad or some other issue. And testing is the best way.

Believe it or not this happens all the time and not just to you. The truth is most of us put in a lot of effort for it not to happen to us. :shock:
I have learned not to expect much help if any from the suppliers, don't even know if there is a hand full that are worth their salt.

by audacibus » Sep 26 2021 9:38am

Thanks for the answers.

Funny in every online forum there seem to be the same arraignment of characters. Nuff said.

Just to clarify a few things: I am at my best mechanically, troubleshooting and reasoning stuff, and at my worst electronically. I do not pose as a specialist in electronics of any kind at all.

Bike was purchased from a client with a broken rotor and some other bike issues, he decided to part with it and I got it for a song. I abused no battery. After fixing the bike and getting back to rolling, I realized that the battery was dodgy.

Opening a motor and changing the rotor are things that I can do very easily and with great attention to detail.

Not sure what abusing a battery means. I admit to swearing at it several times, so perhaps that is what you guys are referring to, lol.

I can do what I know how to do, and what I do not know, I research and ask. That is why I am here for.

john61ct most of your response is incomprehensible, what I understood very clearly is that you are immensely rude.
So, if you are not going to help I do not need your abuse.

99t4 as mentioned above I do not come from an electronics background.
I could not find specs for wolf pack V1.
It seems to hold steady charge.
I am fully charging now and will measure voltage.
When I connect the charger and immediately turn on the display it starts by showing 94% charge.
29.5v is the voltage I get measured from the XT90 connector that goes to the motor. Also from the charging port.
Yes, battery fully potted.

Manbeer I am an old guy and do not ride the bike fast or hard, normally I go 14 mph with a bit of pedal assist, on 5th gear.
This bike comes with history unknown. One outing the motor heated up like hell, I was using it in the highest gear (smaller sprocket), then I did some reading and learned that these motors like to spin a lot. Did not have overheating again.
But battery started deteriorating quickly. First I was able to do 20 miles, then 18, now 16.
Thanks for the suggestion about the Grin simulator - will work on that.
What "more battery" to push a ludicrous would be?

I knew long ago I needed a new battery and that the bike came with this problem, just was delaying the inevitable, I guess.
Any recommendation as to a non-wolf batt that is cheaper in price and with similar quality?

As a side note, Luna's mighty mini display suddenly and without warning started to shed its rubbery bits in a similar fashion to foam upholstery when suddenly disintegrates. As usual Luna does not give you any more help than selling you a new part. In this case I was treated with the "this never happened to anyone" remark. If anyone knows where to find a used or broken one I can cannibalize for the housing, would be grateful.

Thanks
 
ZeroEm I cannot make any sense of John61ct post because I am not at his level.

I do not need to be spoon fed, but I cannot work out the jargon either. SoC? I googled it. 294,000,000 results.

SoC as in "system on a chip"? Is he meaning the Battery Management System? The battery is potted so it is good or bad, nothing else can be done unless there is something and that is what I am asking....

Glad to LEARN how to test the best way. Any tutorial here?

I KNOW I have a battery issue. I am ASKING this forum if there is something I am unable to see. Buying a battery is easy! Realizing that you just spent $600 and the problem was elsewhere is a hard pill to swallow.

Then, this general assumption that I got a pristine new in box battery and kinda trashed it, again, I know how to treat a battery but HAPPY TO LEARN MORE. Former owner knew battery needed changing and that is possibly what cemented his decision to part ways with the bike.
 
SoC is State of Charge, as a percentage.

Very difficult to measure accurately, so usually way off, cannot rely on that.

SoH is State of Health the capacity remaining compared to the actual (not rated) when new.

At 14S, 58V is Full, some use 58.8V but that is stressful max, reduces lifespan.

42V - at rest over an hour isolated - is much lower than such a battery should ever be allowed to go, 50V would be much better for longevity.

Actual LVC needs to be calibrate for V sag/bounceback, depends on C-rate, discharge current level.

Batteries are a consumable, but

by not implementing such a cutoff, a pack might reach EoL after just a few dozen cycles rather than a few hundred.

Also buying a pack twice as big (in Ah capacity) cuts the C-rate in half, can triple cycle lifetime.

Some people don't care, buy a new pack every month.

Others need to learn the details of this stuff, gauge the SoH of each pack, proactively replace it before EoL arrives so no surprises.

Obviously those selling packs are not going out of their way to helping users get longer lifespan.
 
This is random, but have you tried leaving the battery plugged in for several days to balance the cells? Sometimes this will help. also check voltage being output from charger. I have had customers where it appears something else is wrong and the charger is the culprit
 
john61ct, you still are getting me dizzy with all the jargon and not much info that I can actually put in practice.

No idea what 14s is.

You say tht SoC is State of Charge, as a percentage. Very difficult to measure accurately, so usually way off, cannot rely on that.
Yet you do not provide any info about checking these things.

Layman's terms would be ideal...

Manbeer, leaving battery plugged to? Bike? Charger? Yes it has been and it is plugged to the latter.
Voltage output from charger is 58.9v

Fully charged battery is showing at 58.5v
 
It would be like teaching a full undergrad course to get you up to speed if you don't know what 14S means, sorry ain't no one got time for that level of handholding.

14 cell/groups in series is how you get to "52V nominal".

Read past threads, do some googling, look for 101-level resources like Battery University

then ask some more specific questions.
 
I already told you, john61ct, go away, you add nothing to the equation.
Continue with your ego trip elsewhere. Go and play superior being on another thread.
 
I have this battery on my trike and had some concerns about it. It's fair to say I've only been charging it to 80% and recharging about every 3-4 AH used.
Tinted_Liquid-Luna_Wolf_Pack-Frontside__36409.1556187840.jpg


Charge it with the 300W 1-5A Charger. Normally charge it to 80% and top up after each ride. Last time I charged at 100% at 3A rate.
Battery at 58.1V per charge chart thats 96%. Given losses and normal drift thats pretty good.

Most of the rides are kind of Superman rides, up the hills not down. Nothing here is close to flat. I measure human input in watts as well as motor output thanks the CA3 & Thun Bottom Bracket. After 33 miles so far its down to 50.0 volts. Per the chart in the manual that should be 47.5% remaining.

96% - 47.5% = 48.5% consumed per the voltage chart.
Also the chart indicates a full range from 0 ~ 100% as 42.0 ~ 58.8V - that's important further down.

389 Watt-Hours (WH) consumed by motor.

My battery was rated at 13.9Amp-Hours (AH). To get the total wattage capacity take the average voltage multiply by the AH.
50.4 Volts (average) * 13.9 AH = 700 Watt-Hours total. (I never run lower than 25%).

Knowing the battery should have 700 WH (100%) and 389 WH (55%) were used as measured by the CA3 so 45% should be remaining. Close enough to the 47.5% indicated by the CA3. Not bad considering the use it's already had.

I pull 35A peak for a few seconds and 15A steady state with virtually no visible heating on a Flir camera.
 
Recapping,

I have a Luna battery 52v.

Fully charged reads 58.5v

Battery discharges to about 75% on display then dies.

Measured voltage after this happens 29.5V

I plug it in again and to charge in "full" it takes about 3hs which is quite short charging time.

Battery resting fully charged reads 58.3V

So is battery dead or not or there may be something else happening?

If buying new battery, any recommendation as in brand, model and where to buy? Motor is a Bafang BBSHD with Ludicrous V1 controller on a Luna Banana fat tyre.

Thanks
 
Yes as stated the battery is very likely "dead" as in past EoL, SoH below 60-70%

IMO 99% sure

The only way to be **certain** is

>> a remaining Ah capacity test, even if only rough.

And even if it is proven so, does not mean that the problems that murdered it, do not need to be corrected

or your next pack may only deliver 10% of the cycles it could if treated properly.

I am not doing anything here other than trying to help you. But you must put in (most of) the work to learn enough to be able to understand what I am talking about.

At least enough to be able to ask the right questions.

http://www.catb.org/~esr/faqs/smart-questions.html
 
Well it looks like you have broken glass for breakfast instead of corn flakes john61ct, and I am not going to change that.

I am not that much into "I wanna become a battery expert"

I took this bike third hand, with mechanical issues. It is different if I start with a brand new battery and this dies after 2 months of the light use I give these things.

So at this stage will get a new battery and start from scratch. Just wanted to triple check in this forum that a new battery was the way to go.

Still, do not need the excessive amount of time you spend in blowing your own trumpet and patronizing me. I am a 60 yo guy and do not need this.

A link to how to perform a "remaining Ah capacity test" would be helpful but you like to talk and talk without substantiation.

A suggestion as to alternate batteries to the expensive, out of stock luna wolf pack v2.0 would be helpful also.

I expect to be banned at any time from now on. You have a lot of friends in here john61ct that condescend to your bullying.

So be it. Keep your inbred forum for yourselves and disincentive any new member from coming in. You john61ct should be named endless sphere customer relations specialist and new member acquisition manager.
 
Well, best way really is buying a spot welder and building your own packs once you find cell vendors you can trust. Or finding a pack builder near you, same continent anyway.

I can say EM3ev and Ping are / were pretty good.

Trying to save money will only waste it, getting crap quality ensures short life and poor performance, but I suppose you might get lucky on Ali, always a roll of the dice.

Same with not getting up to speed on the details, I am very far from being an expert, but know enough to stand a chance of getting decent value out of my investments in batteries.

Cap tests really are best for one single cell at a time, after atomizing an old pack or before assembling a new one.

I can't recall seeing dummy loads or hobby balance chargers that go all the way up to 14S voltages.

Just realize a quality pack is often worth as much as all the other components put together, and key to them performing well.
 
It is a learning curve for sure. I can translate for you. I'm not at a high level, just understand the basics or think I do.
This is the right place to learn. People here from all over the world at completely different levels. Don't understand some thing just ask. Google search up in the top corner of this page to search this forum. Most if not all info is here. Just finding it takes some time.

I will look for a tutorial. The advice above is good place to start, then if you want to go farther you can.
For replacement battery. trusted and reliable battery suppliers
There are cheaper batteries but do not recommend them that is on you and may get lucky.

Was going to post this for you but to late.
by nicobie » Sep 26 2021 4:06pm

For the OP (original poster) :mrgreen:

viewtopic.php?f=7&t=38854

Don't hurt to learn about lithium batteries. They will be with us until something better comes along. Bet you know about lead Acid batteries. When one cell goes bad it will charge up but drops quickly when used and be ready for replacement.

Good place to start is
by Manbeer » Sep 26 2021 11:46am

This is random, but have you tried leaving the battery plugged in for several days to balance the cells? Sometimes this will help. also check voltage being output from charger. I have had customers where it appears something else is wrong and the charger is the culprit
The reason for this is some cells get low and they only balance (most of the time) when the battery is fully charged. This is a slow process if they are badly out balance. If your battery charger is working so check to make sure it is hitting top voltage for that battery. 14s x 4.2 = 58.8v Max, never over. You stated
Fully charged reads 58.5v
was this after the charger was off and unplugged? How long did it rest before?

Talk about the battery for a min: Batteries are made in different voltages. They are talked about in voltage ranges and nominal voltage. Using how many cells are in series (s) stops guessing (Then there is cell chemistry, later). Your battery is "14 cells in series" (14s). Most cells are 100% at 4.2v, 50% or nominal at 3.6v some use 3.7v, 0% at 3.0v. So 14s at 0% SOC is 14 x 3v = 42v.
This is why 29.5v is bad. As not all cells discharge evenly some could have hit 0v. Charging from there can cause fires so most will not encourage you to mess with a battery that has been discharged that low.

Best way to tell after trying to balance it and it does not work is to open it up and check the voltage on every cell group.
Best is I refer you to Threads from here.


by audacibus » Sep 26 2021 11:05am

ZeroEm I cannot make any sense of John61ct post because I am not at his level.

I do not need to be spoon fed, but I cannot work out the jargon either. SoC? I googled it. 294,000,000 results.

SoC as in "system on a chip"? Is he meaning the Battery Management System? The battery is potted so it is good or bad, nothing else can be done unless there is something and that is what I am asking....

Glad to LEARN how to test the best way. Any tutorial here?

I KNOW I have a battery issue. I am ASKING this forum if there is something I am unable to see. Buying a battery is easy! Realizing that you just spent $600 and the problem was elsewhere is a hard pill to swallow.

Then, this general assumption that I got a pristine new in box battery and kinda trashed it, again, I know how to treat a battery but HAPPY TO LEARN MORE. Former owner knew battery needed changing and that is possibly what cemented his decision to part ways with the bike.
 
Leaving your battery at high voltage is the fastest way to get a new battery.
Even when I am riding everyday, when I come home I just charge to 56 or 57V and before I ride I top it up to 58.8V so it sits at high voltage for very little time.
 
Simplest approach is to get an inline power meter.
Something like a "Watts-up" however I happen to prefer a DROK like this:
https://www.amazon.com/dp/B07FYHTBD2

Goes In
Connect "inline" between your battery and charger when charging.
That will give you how much power it has taken to fully charge your battery as well as the final charge voltage level.
Note that the "charging" voltage is always higher than the "full charge" voltage after charger has been disconnected and the battery allowed to rest a bit.

Goes Out
Connect "inline" between your battery and controller when riding.
That will give you how much power you have actually used from the battery as well as the current voltage level.
Observe the meter readings at various times during your ride to see what the current voltage level is and what power consumption has been. You may find that at some point you get a sudden, steep voltage drop.

Then compare your "goes in" with your "goes out".

In LIne:
That means the meter needs male/female plugs matching the charge/discharge connectors on your system.
Is Luna still using those oddball 3 pin microphone plugs?

The battery BMS tends to be the weakest link and the most failure prone bit in Chinese built battery packs.
Luna is NOT building their own battery packs.
 
markz said:
Leaving your battery at high voltage is the fastest way to get a new battery.
Even when I am riding everyday, when I come home I just charge to 56 or 57V and before I ride I top it up to 58.8V so it sits at high voltage for very little time.

Yes but with the usual poorly designed balancing circuitry in most BMS

(note OP has not stated they even have one)

the too-high "start-balance" setpoint is not adjustable

and the pack needs to get **higher** than that just to get started

also a too-low balance current rate means

completing the process can take literally **many days** if the delta was allowed to get too far out of whack.

This is why I stated it really is necessary to view the per-cell voltage levels to know what's going on, and avoid further damaging the pack.

This risk, along with the fire danger (boom bad) can be reduced by using an adjustable power source that gets up to just over the "start-balance" setpoint, and feeds a very low current, just over the balance current rate.

OP please ignore all this if you have no
BMS or other device capable of balancing.

Come back to it later when you start researching that topic, which may or may not be implicated in your current situation.
 
LewTwo said:
Simplest approach is to get an inline power meter.
Something like a "Watts-up" however I happen to prefer a DROK like this:
https://www.amazon.com/dp/B07FYHTBD2

Here's another

https://www.amazon.com/gp/product/B07Z91FWT9

"Coulomb-counting wattmeter" is a generic term, measures Ah in both directions.

Only the "out" is used to give capacity, always less than the "in"

Measure from your charger's definition of 100% Full, down to 42V **and no lower**

john61ct said:
From 100% Full, down to 3.0Vpc, Constant Current at a very slow rate, over 10 hours (0.1C)

Ideally compared to an identical test performed at commissioning, while breaking the pack in.

Note that last part for doing with your next pack.

 
john61ct said:
https://www.amazon.com/gp/product/B07Z91FWT9

"Coulomb-counting wattmeter" is a generic term, measures Ah in both directions.

I have a few of those. None of them agree on voltage or amps, so I can only use them to compare against previous results from the same meter.
 
john61ct said:
Yes but with the usual poorly designed balancing circuitry in most BMS

(note OP has not stated they even have one)
Well he did state that it was a "Luna Wolf V1 52v Battery Pack"
Current version is the V2: https://lunacycle.com/luna-wolf-v2-52v-battery-pack/

That has a BMS and best I recall (I am a bit senile) it is a FULLY potted battery so the end user has access to nothing but the charge and discharge connectors w/o "carving" into the battery pack. I am going to be polite and not say what I think of that design.
 
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