Could you pls help me about the Diamond HV Series Semi-Solid-State Li-ion Battery

[kankorn]

I looking for a new battery so my brother brought the Foxtech Diamond Series Semi-Solid-State Li-ion Battery 6S 16000 mAh so I tested it by hovering over my Hexacopter but the flight time did not reach my calculation. It just hovered for 12 mins till the batt failsafe alarmed but my calculation is 16 mins (batt capacity * safety factor(0.8)*60/average amp draw). so I’m going to buy a Diamond HV Series Semi-Solid-State Li-ion Battery 12S 32000 mAh. Does anyone has a semi-solid state Li-ion HV battery discharge log> I want to study The discharge character of it
or the formula to calculate flight time of this type of battery:pray:

[xfacta (Shawn)]

Have you got a .bin log you can share?
Did you set failsafe voltage levels suitable for a Li-ion battery or leave the Lipo values in place?

In the blurb, without documenting any actual tests, foxtech claim

The discharge interval of each battery cell is from 2.7v to 4.2v

which may produce these:
for 6S

BATT_ARM_VOLT,18.50
BATT_CRT_VOLT,17.40
BATT_LOW_VOLT,18.00
MOT_BAT_VOLT_MAX,25.20
MOT_BAT_VOLT_MIN,16.20

for 12S

BATT_ARM_VOLT,37.10
BATT_CRT_VOLT,34.80
BATT_LOW_VOLT,36.00
MOT_BAT_VOLT_MAX,50.40
MOT_BAT_VOLT_MIN,32.40

Using the capacity should work fine provided you start with a fully charged battery and your current sensor is accurately calculated. You can confirm the copter’s used capacity when you recharge the battery after a test flight.
I would always still set the voltage failsafe values just in case there’s anything unexpected, or for those times when you dont start with a fully charged battery.

Note that much documentation says the typical Li-ion cell discharge minimum voltage is 3.0v although in copter land we use 2.8v as a typical critical voltage level for Li-ion.

[mtfunder (Mark Funderburk)]

As Shawn said you need to lower your failsafe voltages to match the battery chemistry, that’s where the extra capacity is.

The numbers he gave should be very safe and match with my own testing (we actually go a bit lower even, but it’s diminishing returns and you really need to know what you are doing).

[mtfunder (Mark Funderburk)]

See here for discharge curve:

Foxtech 30000mah 6S Battery, any one try it?

So 6 months later I finally have got some more time to work on battery testing. This is in regards to the Foxtech 30AH 6S Battery. I built a battery testing rig that allows me to pull a constant current and dump the power into a set of high power low ohm resistors. This allows a much more precise and controlled measurement of the batteries capacity and drain curve. This is particularly important for the Foxtech “Semi-solid lipos” becuse in order to get near the rated capacity you need to drai…

[kankorn]

Here is my hovering test log file

solid state 16A flight time test @full load.bin

my batt parameter is
BATT_ARM_VOLT 38.30
BATT_CRT_VOLT 36.00
BATT_LOW_VOLT 37.20
MOT_BAT_VOLT_MAX 49.20
MOT_BAT_VOLT_MIN 33.60

[manavgandhi17 (Manav Gandhi)]

Just a quick note. The Diamond HV series of batteries are supposed to be charged up to 4.45V/cell. I see from the logs you started at 4.1V/cell.

Source: https://www.foxtechfpv.com/diamond-hv-series-semi-solid-state-li-ion-battery-6s-16000-mah-44000-mah.html

This is probably the reason for your flight time difference.

[manavgandhi17 (Manav Gandhi)]

I also see that a 35A draw is causing a 5V sag in battery voltage (!!). Seeing battery sag is expected, but 5V is a lot for such a low amp draw relative to your pack size.