4.21V 4.22V can be ok if balancing, 4.30V should be flames!!!!!
It may even be that the charger is reading off by a few volts.

NEVER STORE AT 0%  45% - 65% is acceptable

Nominal Voltages

Nominal voltage is the default, resting voltage of a battery or pack. It is not, the full charge voltage of the cell or pack.

LiPo batteries are fully charged when they reach 4.2v/cell, and their minimum safe charge/dead is 3.5v/cell. 3.7v is around 1/4 of the battery cell and that is the nominal charge of the cell.

50.4V is a 100% fully charged 12S Lipo battery.

We want to keep our battery above 0% or 3.6V Per cell.
The FocBox Unity/ESC programing will be setup to control prevent your battery from becoming to low.


A Single LiPo cell has a nominal voltage of 3.7V.  A 6S Lipo, that means that there are 6 cells in series  (which means the voltage gets added together).
This is sometimes why you will hear people talk about a "
12S" battery pack - it means that there are 12 cells in Series. So a six-cell (6S) pack is 22.2V nominal, a twelve-cell (12S) pack is 44.4V nominal, and so on.

Battery Voltage Cutoff Start and End Values

Battery Voltage Cutoff Start and End Values on your ESC are set at Better.
End is when the system stops giving you power.
This means you are now walking.

The Cutoff Start is when the system starts to lower your power output/speed/throttle. This will feel like a car running out of gas, and eventually wont move forward. You should still be able to brake, but best to stop before you reach 0%. Or your Cutoff END.

To prevent the battery from getting too low, we define our own cutoff Values in the Unity/Electronic Speed Controller.  These may be set at 46.40V Cut off Start and 43.80V Cut off End.  (2.6V difference)

This puts the battery at
1-5% when done with a ride. This is using your battery to a safe potential with little head room. This puts your cells at 3.65v which is 0.15V from what is considered dead, remember your cells never drain in perfectly in sync.

When a Lipo gets under 10% 0r 3.50v the cells become in-balanced more and more while riding/draining the battery. This is harmful for the battery as one cell can drop dangerously low, let me explain.

We have 12 cells in a pack. These cells start off balanced at 4.2v. When riding each cell drains at a different rate.  This is to due with resistance and other variables in each cell.

The ESC reads your 12 battery cells as a single battery.  So when you get to 10% of your battery, the 12 cells have been draining at different rates.  This can result in 1 or more of the 12 cells being lower than 3.51V or dead. If this happens the cell will get  hot and can become unstable. To prevent this we set Cutoff Values higher than 3.50V True Dead. This higher value helps compensate for imbalances when riding.

No single cell drains at the same rate as the rest of the pack. Some cells may drain beyond the set limits. It is recommended to add some head room to the limits of your battery pack when setting these cut off values. The below values are choices you can make based on my own personal experience but is best to choose a setting that is not using the limits of the battery.



3.40*12 = END 40.80 + 2.6 = START 43.40 Beyond Limits of Battery
Will experience heavy unbalance and High heat)

3.50*12 =
END 42.00 + 2.6 = START 44.60 Limits of Battery
(May experience heavy unbalance and High heat)

3.60*12 =
END 43.20 + 2.6 = START 45.80 Good
(Recommended Limits of Battery)

3.65*12 = END 43.80 + 2.6 = START 46.40 Better

3.70*12 = END 44.40 + 2.6 = START 47.00 Best
Never experience heavy unbalance and High heat Less range)



The safest charge rate for most LiPo batteries is 1C, or 1 x capacity of battery in Amps.

50.4V is a 100% Full Lipo Battery.
36.0V is a 0% Dead Lipo Battery. Understand that 36.0V would still be considered having voltage but It is not made to drain to 0.00V.

This would destroy the battery chemistry, cause swelling and potentially cause a Fire. 40.08V is also 0% Dead Lipo Battery based on the photo of a charger above.