Battery loosing charge quickly

Jun 8, 2018
29
0
57
Bristol
#1
Hello forum. I had a injury and did not ride my Peugeot e bike for 3 months. This week the battery discharged while riding from 100 to 20% in the distance that it would normally go to 75%. I have charged and rode it four times with the same result. The charger gets hot and works and the bike controller displays fully charged. Battery is a joycube Philip. Is this a battery or b.m.s fault. How do I cure this. Thanks Mark S
 

wheeliepete

Esteemed Pedelecer
Feb 28, 2016
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Devon/Dorset
#2
How old is the battery? Your lack of range could be partly down to the drop in temp. in the last 3 months. Where do you charge your battery? They are best stored cool,but need to be charged at room temp to attain full capacity. If you have a multimeter measure voltage after charging. This may help show any problem it may have internally.
 
Jun 8, 2018
29
0
57
Bristol
#3
Hi the battery is 18 months old. It is a 5 pin 8.8ah 36v Philion. It is always charged inside. Typically ridden 15 miles to work 're charged then ridden home. What can I check.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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#4
A Pete has said charge it and measure the voltage and let us know the result.

It could be that being left for 3 months a BMS bleed resistor may have allowed a cell group to discharge and unbalanced the battery, the battery may not have rebalanced itself if a cell group is much lower then the others.
In the case of failing cells or a bleed resistor fault fully charge the battery, make a note of the voltage and leave to rest for 48hrs after this period or at 12 hourly periods make a note of the voltage each time to see if there is any voltage decrease.
 
Jun 8, 2018
29
0
57
Bristol
#5
Thanks both for the advice. I will get a volt meter to so if there is any loss. In view of the conning weather I may also wait for things to warm up
 

wheeliepete

Esteemed Pedelecer
Feb 28, 2016
1,220
161
55
Devon/Dorset
#7
First reading is 41.7 volts
Well that is fairly promising from a balance point of view, only .3v off max. voltage. Although it may show that 1 group of cells is slightly lower than the rest, it's not an indication of pack capacity. As Neal has said, if you can, leave the battery for 48 hours and measure again.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
6,947
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#8
Got a voltage meter. First reading is 41.7 volts
Pretty well balanced then, ride the bike a few times to charge /discharge the battery and see if regular use improves the discharge usage.
 
Jul 27, 2016
188
17
South Yorkshire; S11
#9
and remember that batteries don't give the same range in temperatures approaching freezing...
 

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