From f559b878b0195ed7ecc981cb43b485d849b07489 Mon Sep 17 00:00:00 2001 From: Stavros Korokithakis Date: Mon, 28 Dec 2020 01:18:04 +0200 Subject: [PATCH] Updates --- content/drone-stuff/inav-tuning-tips.md | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/content/drone-stuff/inav-tuning-tips.md b/content/drone-stuff/inav-tuning-tips.md index a94234f..2c508ff 100644 --- a/content/drone-stuff/inav-tuning-tips.md +++ b/content/drone-stuff/inav-tuning-tips.md @@ -13,14 +13,16 @@ Here are some general INAV tuning tips and things I've learned throughout my bui ## Battery monitoring -To monitor how much battery you have left in flight, voltage isn't a good indication because it can sag a lot. mAh is also not a good indication, because it doesn't decrease linearly with voltage. Energy is a better way, using the "Wh drawn" INAV OSD item. In addition, INAV has heat loss compensation for the energy meter, which gives you a more accurate reading. +To monitor how much battery you have left in flight, voltage isn't a good indication because it can sag a lot. mAh is also not a good indication, because it doesn't decrease linearly with voltage (when voltage drops, you need to consume more amps for the same amount of motor RPM, and thus thrust). Energy is a better way, using the "Wh drawn" INAV OSD item. In addition, INAV has heat loss compensation for the energy meter, which gives you a more accurate reading. To calculate the Wh a battery can give, the best way is to charge or discharge it and see how many Wh were spent, if your charger shows you. Another way is to get a rough estimate using the formula `no_cells * 3.7 * Ah`. So, for a 1800 4S battery, the maximum Watt-hours are `4 * 3.7 * 1.8 = 26.64 Wh`. You should not discharge more than 80% of that value, or you risk excessive wear to the battery. For a 4S battery, I go with a rule of thumb: The maximum Wh is `mAh / 85`, so for a 5000 mAh battery I'll land after 58 Wh consumed, which is around 80% of the battery consumed and gives a small margin for error. +More details can be found in the [battery page](https://notes.stavros.io/drone-stuff/inav-tuning-tips/#battery-monitoring) in the INAV wiki. + _(Thanks to Michel Pastor in the INAV Telegram group for this tip.)_ * * * -*Last updated on December 20, 2020.* +*Last updated on December 28, 2020.*