Do lithium batteries last longer with frequent part charges? I'm now not so sure due to the following accumulated evidence.
1) I owned three of the original eZee Li-ion batteries which were all treated with care, and since I'm not a commuter most of the charges were frequent and part only. Two failed within 6 months and one lasted only 10 months, while others using the same batteries on the same model bikes, but commuting and exhausting most of the charge each day, were sometimes getting 12 to 18 months use from a battery.
2) My experience with the latest type of li-ion on test hasn't shown any problems with fully discharging most of the time during the test program and it's still in use at 25 months. Others testing this type have in some instances reported failures by 18 months, despite most frequently part charging.
3) Panasonic intend their 10 Ah battery for the pedelec unit to be fully discharged every time any meter or capacity deviation is seen, and they make no mention of a need for frequent charging, instead publicising the full ranges that can be attained. They were also the first, and for a long time the only company giving a two year warranty without restrictive usage conditions attached, indicating no fear that full discharging does harm.
Obviously the first and second cases could be affected by differing conditions like terrain, rider etc, but the accumulation does seem to indicate that fully discharging doesn't do any damage and may even be preferable.
Conclusion: Based on the likelyhood that those part charging will typically carry out 2 to 4 part charges totalling one full charge, it could be that this average of 3 times taken to the full charge point could result in more stress than the stresses of one full charge point and one full discharge point when fully discharging, the latter numerically smaller.
My own intention for the future is to just use the content as convenient with no regard to any special charging pattern.
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1) I owned three of the original eZee Li-ion batteries which were all treated with care, and since I'm not a commuter most of the charges were frequent and part only. Two failed within 6 months and one lasted only 10 months, while others using the same batteries on the same model bikes, but commuting and exhausting most of the charge each day, were sometimes getting 12 to 18 months use from a battery.
2) My experience with the latest type of li-ion on test hasn't shown any problems with fully discharging most of the time during the test program and it's still in use at 25 months. Others testing this type have in some instances reported failures by 18 months, despite most frequently part charging.
3) Panasonic intend their 10 Ah battery for the pedelec unit to be fully discharged every time any meter or capacity deviation is seen, and they make no mention of a need for frequent charging, instead publicising the full ranges that can be attained. They were also the first, and for a long time the only company giving a two year warranty without restrictive usage conditions attached, indicating no fear that full discharging does harm.
Obviously the first and second cases could be affected by differing conditions like terrain, rider etc, but the accumulation does seem to indicate that fully discharging doesn't do any damage and may even be preferable.
Conclusion: Based on the likelyhood that those part charging will typically carry out 2 to 4 part charges totalling one full charge, it could be that this average of 3 times taken to the full charge point could result in more stress than the stresses of one full charge point and one full discharge point when fully discharging, the latter numerically smaller.
My own intention for the future is to just use the content as convenient with no regard to any special charging pattern.
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