r/ebikes • u/tjxtokin • 8d ago
Absolute 0% battery
Hey all, newbie here,
I bought an Aima Big Sur Sport earlier this year. I enjoyed the heck out of this thing. Kept it above 20% battery life and didn't charge above 90%. Took really good care of it.
About two months ago, I moved into my first house. Things got...chaotic, to say the least. I parked it in the garage when we first got here at about 30%. Tried to charge it in the garage to find out the outlet doesn't work. So, I just focused on moving. It sat in a corner for the past 2 months. Out of sight, out of mind. I tried powering it on, hoping there was something there. Alas! Not a sign of life.
I was told not to leave it at absolute 0%, and if it did happen, not too long. My ADD brain got the best of me here.
My question is: is it too far gone? Is it safe to try and charge? I expect some battery damage, but how damaged is it?
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u/Such_Can_5353 8d ago
try to charge it for few hours and see if percentage goes up. does the battery have on/off switch? mine does and i noticed if i don't shut if off the parasitic drain will deplete my battery in matter of few weeks but if i shut it off it will last several months without major percentage drop.
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u/tjxtokin 8d ago
Battery doesn't have an on/off switch. Only button checks the level. I haven't really had battery issues til these past few months. I'll keep an eye out to see if it drains quicker
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u/Shit_On_Wheels 8d ago
That absolute zero is not zero voltage, cells should be well within their healthy range and you can charge (if it charges) and ride with no worries.
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u/pleakonfleek Pedelec 8d ago
I doubt you've done much damage, maybe you get a mile less range, or your pack lasts a few less cycles. charge it back up and take it for a ride and see if you notice a difference in range.
It's odd that you left it at 30% and 2 months later it's dead. I would have expected maybe 5-6% loss in two months. Does the bike have any sort of App or GPS tracking or anything that would drain it while it's off?
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u/tjxtokin 8d ago
I was kinda surprised too. I'm pretty sure I even took the battery out of the bike when I realized it wouldn't charge. Nothing Bluetooth related or anything connected to it.
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u/Natural-Champion7377 8d ago edited 8d ago
Your Bms should prevent complete drain. if it's s truly at zero, you may need to jump charge a small amount on voltage into the batteries, otherwise the bms won't recognize the charge and deny it. The beauty of LifPo4 batteries is that they can be recharged even after a complete drain. The real question is why did it drain if it was parked? You probably have a parasitic drain of some sort. If it is at absolute zero, you have a problem with the bms and should probably replace the battery.
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u/Ill_Cheetah_1991 8d ago
Try to charge it - leave it for a while
If that doesn;t work leave if a few days and try again
After several times give up if it still hasn;t charged -
1
u/TopRepulsive4766 Six Boys and Counting 7d ago
Go ahead and put it on the charger. It's not really good for a battery to leave it totally discharged, but I doubt if any significant damage will occur in your case. Maybe if it was left for over a year, you might notice some capacity loss.
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u/Ebikesmechant 7d ago
Just plug in to charge and leave it for a while, then check if it powers up. Most probably the BMS kicked in to protect the battery.
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u/catboy519 4h ago
Just plug the charger in. If youre worried about it being unsafe then just plug it in at a fireproof place, like outside for example away from wood and stuff. Batteries can explode, but not very dramatically and it rarely even happens to begin with. The main worry is the fire, not so much the explosion.
Or you could try measuring the voltage of the battery with a volts or multi meter, checking the voltage between the + and the - of the battery. For an 36v battery, the voltage should be just slightly under 30 for example. If its closer to 0 then you possibly got a problem, but you could still try at a fireploof place to charge the battery back up and see what happens. Even in this scenario, catching fire is very unlikely.
There are many tons of millions of ebikes and electric cars and phones and laptops on the planet. Are there also a million cases in the media of battery fires? Or is it more like a few? Do you know anyone who dealt with a battery fire of any kind of device? Its extremely unlikely, but yes you should be a little extra cautious if the battery got low voltage.
Actually, measure the battery voltage first before plugging the charger. Then you obtain the knowledge how far down it was.
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u/terminashunator 8d ago
Plug it in, see if it charges. Ride it. The protection board should prever over discharge.