Battery percentage

[cyclenut1952]

May I also ask, if my battery is classed as 36v where does 42.2 come from, as I am totally confused.

 

[anotherkiwi]

36v is the average or median charge, cells are 3.7v or 3.6v nominative. When you charge to full they go up to 4.2v so 10 x 4.2 = 42v when full.

Don't worry, the first 200 m or so will see charge drop to 41v where the discharge curve smooths out.

 

[Nealh]

The cell have a charge/discharge voltage range typicall min is 3.2v and max is 4.2v, the middle voltage 3.6v is the battery nominal voltage. For a 36v battery this will be 32v & 42v respectively, though 42v is the max sometimes the charge may be a bit lower any where between 41.5v and 42v.
A 36v battery is 10 cell bricks/blocks in series (10 x 3.6 = 36).
It is practical to buy a cheap mustimeter so you can always know the battery SOC (state of charge).

 

[cyclenut1952]

Thank you for replying, i suppose I am getting paranoid about batteries, as a newbie I just want to get the longest use out of it.
I do appreciate all replies

 

[Nealh]

When buying a ebike battery they are heavier, larger and certainly more expensive then other lithium batteries used, so your reasoning to max out the life is a good one. Looked after well there is no reason why it shouldn't last 5 years or more though by year 5 some aging will have taken place.
To extend the battery life and for good cell capacity life as I mentioned buy a cheap multimetre to use for checking voltage.
After use only charge battery up several hours before the next planned use as keeping the battery at high SOC (for any period ) will degrade the cells a little, you won't notice the degradation by voltage as the cells will charge to max but you will notice capacity loss by lack of range or on an aging battery voltage sag or power cutting out when a high load is applied.
41.5v - 42v fully charge before use and when not being used try and keep the voltage in the range of 36v - 38.5v, if the voltage is say 35v this is ok for a short time of a few days or a week or so but long term not good.
If you use the bike and voltage is low 32 - 35v, there is no harm in plugging the battery in for 30- 60mins or so to raise the voltage above 36v. You can then cease charging until you carry out the next full charge.
Over winter if not using the battery charge to 38.5v max and check the voltage (as a precaution) once a month to make sure it is good. Lithium does well when not in use stored in a dry cool place above freezing ( not a damp shed ) but a linked lean to or garage to a house or a porch area not prone to freezing.