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I've been thinking about adding some more... but wouldn't mixing new battery's with used battery's be bad? I've probably only charged the battery 10 times though... so I guess not
Your pack will only be as good as the most worn batteries or the weakest. So generally it's not a good idea but not the worst. Just remember the pack is only as good as your weakest batteries
 

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What silverbullitt7 is saying is true but you have very few cycles on the pack. now whould be the time to add a row before you get 40 or 50 cycles on it... You can add a row of cells even after the pack has aged or even replace single cells that have started to fail with new cells. With the negative effect of the new cells will never see their full potential because the charger will stop when it sees that the lowest cell ( most worn cell) is fully charged...
 

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I hooked up the new controller and it doesn't have soft start!!! Its so nice to actually properly be able to feel the acceleration...

But here's my problem, I made sure that the battery was pretty low before I hooked up the controller, incase I did anything wrong. So the voltage was probably around 46 volts... once everything was hooked up and I pegged it, it didn't stutter or anything, it just went (it pulled 1,300 watts, but almost felt like a fully charged battery. So I was riding it like this for a while, and watched the voltage... and the voltage was going to to 38 under high load! So I hooked my bms back up, but that didn't change anything! It still sags down to 38 volts (possible more, I just didn't want to risk going any lower)

Did I cause damage? How am I supposed to tell if my low voltage cut off is working?
 

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38 volts is about dead but you need to know where LVC is set to if you still have your SLA bank laying around ( good for testing ) then you can hook it up it doesn't have to be installed in the bike pull off the chain and run it untill your speed control hits LVC...
 

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Is that a 42/36 volt controller if it is then at 36 volts lvc whould cut at around 32 depends if it has auto voltage senceing or not
 

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Sounds like you have LVC set to Disable it should have a setting to Enable then your BMS should kick it out no matter what I wonder what's going on there ?

Where you riding it then you felt it start to slow down and where like UT O then looked at the voltage?

Your going to need to feed at least 40volts to do the test.
 

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Sorry I won't be able to perform the test for a while, our power is out and don't know when it will be back on
 

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I hooked up the new controller and it doesn't have soft start!!! Its so nice to actually properly be able to feel the acceleration...

But here's my problem, I made sure that the battery was pretty low before I hooked up the controller, incase I did anything wrong. So the voltage was probably around 46 volts... once everything was hooked up and I pegged it, it didn't stutter or anything, it just went (it pulled 1,300 watts, but almost felt like a fully charged battery. So I was riding it like this for a while, and watched the voltage... and the voltage was going to to 38 under high load! So I hooked my bms back up, but that didn't change anything! It still sags down to 38 volts (possible more, I just didn't want to risk going any lower)

Did I cause damage? How am I supposed to tell if my low voltage cut off is working?
What I do know is with lipos, 4.2 is Max charge and 3.2 is almost toast. I tried to run my lipos no lower than 3.4 volts. So for your packet depends on how many rows you have. How many batteries in series, and how many batteries in parallel do you have? 13 in a row in series and your pack should have gone no lower than 41.6 volts.
But 38.4 volts for 12 in a row.
Just remember, 3.2v times your series row for the very lowest tou should go.
 

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LI-Ion is more stable then Li-Po but yes if he was running Li-Po he whould be in trouble trying to slow charge it to keep it from puffing...
 

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LI-Ion is more stable then Li-Po but yes if he was running Li-Po he whould be in trouble trying to slow charge it to keep it from puffing...
Not much. The recommendations are no lower than 3.0v per cell. Most likely he was below that depending on his pack specs. But, in my experience, charge it and if it charges it should be okay. But I guarantee he still did some damage. If it doesn't charge, it is for sure dead. I have taken lithium ion and Lithium Polymer to just above their minimum and they still died on me. I don't care how good the battery is, they will fail. All you can do is try not to get very close at all to the minimum which as far as I know is 3.0 volts on a Lithium-Ion and 3.2 on a polymer, I shoot for 3.2 on a ion and a 3.4 on a polymer. That comes from years of experience and I've still had batteries fail at that.
 

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LI-Ion is more stable then Li-Po but yes if he was running Li-Po he whould be in trouble trying to slow charge it to keep it from puffing...
Not much. The recommendations are no lower than 3.0v per cell. Most likely he was below that depending on his pack specs. But, in my experience, charge it and if it charges it should be okay. But I guarantee he still did some damage. If it doesn't charge, it is for sure dead. I have taken lithium ion and Lithium Polymer to just above their minimum and they still died on me. I don't care how good the battery is, they will fail. All you can do is try not to get very close at all to the minimum which as far as I know is 3.0 volts on a Lithium-Ion and 3.2 on a polymer, I shoot for 3.2 on a ion and a 3.4 on a polymer. That comes from years of experience and I've still had batteries fail at that.
That is terrifying to know... I really hope I didn't spend all that money on a battery that I already destroyed... I plugged it in and it charged right up to 54.23 volts.

If I do add another row of 13 cells, is there going to be a noticeable difference in voltage sag?
 

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LI-Ion is more stable then Li-Po but yes if he was running Li-Po he whould be in trouble trying to slow charge it to keep it from puffing...
Not much. The recommendations are no lower than 3.0v per cell. Most likely he was below that depending on his pack specs. But, in my experience, charge it and if it charges it should be okay. But I guarantee he still did some damage. If it doesn't charge, it is for sure dead. I have taken lithium ion and Lithium Polymer to just above their minimum and they still died on me. I don't care how good the battery is, they will fail. All you can do is try not to get very close at all to the minimum which as far as I know is 3.0 volts on a Lithium-Ion and 3.2 on a polymer, I shoot for 3.2 on a ion and a 3.4 on a polymer. That comes from years of experience and I've still had batteries fail at that.
That is terrifying to know... I really hope I didn't spend all that money on a battery that I already destroyed... I plugged it in and it charged right up to 54.23 volts.

If I do add another row of 13 cells, is there going to be a noticeable difference in voltage sag?
I know that ion packs I don't handle the voltage sag as well as a lipo. Check out this info, I hope it helps
https://endless-sphere.com/forums/viewtopic.php?t=84813
 

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Your pack charged up. Its probably ok. I have had some packs that went under voltage multiple times and still pulled through. Other times during a run I kept checking the battery pack and it went from 3.7 volts to 2.8 in a matter of minutes. And it wouldn't charge up after that, it was a dead pack and that was the third time it was used.
 

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I think he is fine he made his pack out of good name brand cells not China knock off junk... If he had used crap cells it whould be over... That's the difference when you use quality components!!!
 

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I kept breaking freewheels so I found a way to upgrade them:
I've owned quite a few of these electric Razor dirt bikes and I have always had the old style. Even my 2015 MX650 has the older style , my red mx500 is 2008 9 or 10 I'm not sure there's no date on it.
Build is 08.
The mx500 is getting a 24v 500w motor and brand new but stock computer and throttle. Stay tuned.
 

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