CHECK IT OUT! Dirt Cheap Battery Volt Alarm!!

[KubKade]

First of all I’ll explain what these little gadgets are. They are really small (about 1.25”x.75”x.25”. It uses digital, red, LED’s to show your batteries voltage. It is powered by the battery you plug in so there are no batteries in the meter itself. They can handle 2s-8s batteries. Along the bottom is a row of pins to plug your battery’s charge lead into. Use the far left pins and plug in the charge lead. It will then go through each cell showing the voltage and the also the total voltage. The coolest feature it has is that you can set a certain voltage (3.8 per cell is the recommended storage charge) and when your battery gets down to that it will beep really loud until you unplug it. They are also very basic and simple to setup. I don’t understand why the guys at FT don’t use something like this. It will significantly extend the life of your batteries because they won’t be under the stress of dying every time you fly. Plus you don’t have to come in hot every time you land. And you can get a pack of 5 for only $13 using the link below! I found out about these from the RCSaylor’s YouTube channel. If you have any questions either ask on this thread or checkout they’re video of these awesome guys.
https://www.ebay.com/itm/23374478614

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[whackflyer]

My way of doing things isn't in your poll... I don't use voltage alarms but I roughly calculate the draw of the power system and come down when I think I should on the first few flights.

After those flights I look at the voltage of the spent batteries and can figure out about how long to fly. If they're a little lower then I would like, I just lower the time 30 seconds and vice versa. I usually try to come down at 3.7-3.8V per cell. I can get within .1 of a volt or so between batteries just using a timer.

I come down a little early if I'm flying hard and allow a little more time if I'm just cruising. Not too hard when you know the demand of your power system and know how long it takes to exhaust a certain size of battery. When you use the same power system all the time you pretty much can keep your times rye same regardless of the actual plane it's in.

 

[KubKade]

My way of doing things isn't in your poll... I don't use voltage alarms but I roughly calculate the draw of the power system and come down when I think I should on the first few flights. After those flights I look at the voltage of the spent batteries and can figure out about how long to fly. If they're a little lower then I would like, I just lower the time 30 seconds and vice versa. I can get within .1 of a volt or so between batteries just using a timer. I come down a little early if I'm flying hard and allow a little more time if I'm just cruising. Not too hard when you know the demand of your power system and know how long it takes to exhaust a certain size of battery.

Ya that works too.

 

[whackflyer]

Ya that works too.

I'm too cheap to buy dirt cheap voltage alarms

 

[KubKade]

I'm too cheap to buy dirt cheap voltage alarms

Lol ya they’re not quite “dirt” cheap😜

 

[Aviador]

I use these. They’re awesome. The alarm is plenty loud enough to hear pretty much as far away as you want to fly🙉

 

[TheFlyingBrit]

First of all I’ll explain what these little gadgets are. They are really small (about 1.25”x.75”x.25”. It uses digital, red, LED’s to show your batteries voltage. It is powered by the battery you plug in so there are no batteries in the meter itself. They can handle 2s-8s batteries. Along the bottom is a row of pins to plug your battery’s charge lead into. Use the far left pins and plug in the charge lead. It will then go through each cell showing the voltage and the also the total voltage. The coolest feature it has is that you can set a certain voltage (3.8 per cell is the recommended storage charge) and when your battery gets down to that it will beep really loud until you unplug it. They are also very basic and simple to setup. I don’t understand why the guys at FT don’t use something like this. It will significantly extend the life of your batteries because they won’t be under the stress of dying every time you fly. Plus you don’t have to come in hot every time you land. And you can get a pack of 5 for only $13 using the link below! I found out about these from the RCSaylor’s YouTube channel. If you have any questions either ask on this thread or checkout they’re video of these awesome guys.
https://www.ebay.com/itm/23374478614

5 View attachment 192675 View attachment 192676

I have a couple, just dont do my trick.
After a days flying I packed up went home and put everything away in my attic. The following day I heard a house alarm going off down the street, I got more annoyed as the day progressed wondering why it wouldn't shut off, or someone stop it.
I went upstairs to look out of my bedroom window to see if I could see which house it was coming from, only to realise it was coming from my attic.
After my last flight, I disconnected the battery from the plane and put my battery in the used Lipo box. However, I had forgot to disconnect the battery alarm, so when my battery got really low the next day the alarm went off.
Sadly I found out too late and the battery was virtually dead and couldn't be revived, an expensive lesson regarding battery alarms "Dont forget to disconnect them after use".

 

[TheFlyingBrit]

Although it cost me a 3s 2200mAh battery which had only had a few flights, I still think these are great tools for the price.

 

[Sir_Lancelot178]

I fly Frsky with an r168 receiver which has a pin that you can splice into VBAT and with no external volt meters or anything is sends my battery voltage back to my radio. There are no stray wires, excess connectors, or the need to use the balance plug on your battery. Since it is telemetry, you can set up alerts when your battery hits a specific voltage and your radio will say the voltage aloud. If I had to mess about with external telemetry sensors I wouldn't bother with telemetry but since it is built into the receiver, it is simple, and comes at no added cost I think it is a really under rated feature of the r168.

 

[danskis]

I've been using the pictured voltage alarm in my powered sailplane for a while. It works well. I use it on the sailplane because I only use the power to get to altitude and hunt for thermals. If I get a thermal then I could be up there for a while and its difficult to mentally gage where you are on battery usage. It comes in very handy for that and kicks off before the receiver "low telemetry" alarm. @Sir_Lancelot178 I've got a QX7 and I'm running the cheaper Radiomaster receivers. Can you point me to a website to find out more about the VBAT splice.

 

[Sir_Lancelot178]

I've been using the pictured voltage alarm in my powered sailplane for a while. It works well. I use it on the sailplane because I only use the power to get to altitude and hunt for thermals. If I get a thermal then I could be up there for a while and its difficult to mentally gage where you are on battery usage. It comes in very handy for that and kicks off before the receiver "low telemetry" alarm. @Sir_Lancelot178 I've got a QX7 and I'm running the cheaper Radiomaster receivers. Can you point me to a website to find out more about the VBAT splice.

Watch from 8:20 to 17:10

 

[danskis]

@IanT - yeah, I did that. Fortunately it was a small inexpensive battery. Now I disconnect the alarm before the battery.

 

[Piotrsko]

Have you tested for how long the ESC powers the radio and servos after low voltage motor shutdown? I personally run out of time before the system gets dangerously low

 

[mastermalpass]

Think I might grab a couple of these for my more high-stakes models. The Blade 500X is definitely not one I want to run out unexpectedly with and the bigger warbirds could do to have this - never thought to look for them.

I don't use telemetry or timers or anything, I just guess. lol

 

[mdcerdan]

I get a couple of those cheap voltage alarms, but I use them when I let others fly my planes. I know how long I can fly certain model and use a timer in the radio.

 

[Paracodespoder]

I also used to use one, stopped using it when my super bee ejected it and the battery and I couldn’t find it (did find the battery). Nowadays I simply guess and almost always come down between 3.7-3.8 volts per cell.

 

[WarpedFactor]

These handy little devices are also available onm Amazon for a very reasonable price! CAMWAY 5PCS 2in1 1-8s Lipo Battery Voltage Tester,RC Low Voltage Buzzer Alarm,Battery Monitor Checker Tester for 1-8s Lipo/Li-ion/LiMn/Li-Fe

RC Saylors did a video regarding them...

 

[TheFlyingBrit]

The R168 has built in Telemetry with one +ve connection to your battery, you can get RXbat data to your TX16s. This can then set it up with an audible alarm to warn you when your battery is low, save having seperate battery alams. No sure if the independant battery alarms would be useful on a glider(ie not loud enough), where as this sytem will warn you through your transmitter.
The R168 will give you at least 1km range and will cost you around $28 which won't break the bank when you consider its a 8ch reciever, with sbus allowing up to 16ch.

 

[WarpedFactor]

View attachment 193362
The R168 has built in Telemetry with one +ve connection to your battery, you can get RXbat data to your TX16s. This can then set it up with an audible alarm to warn you when your battery is low, save having seperate battery alams. No sure if the independant battery alarms would be useful on a glider(ie not loud enough), where as this sytem will warn you through your transmitter.
The R168 will give you at least 1km range and will cost you around $28 which won't break the bank when you consider its a 8ch reciever, with sbus allowing up to 16ch.

Battery telemetry is good for in-flight, but this is more about maintaining battery health over the long haul.

 

[PsyBorg]

Voltage alarms are nothing more then a guestimate when to land. Tried a bunch way back in the day. They can tell you when your peak low gets breached but that's about it. They don't factor in how hard you are flying, what your pack actually is in terms of mah or C rating. ALL those things factor in when using a lipo battery.

The BEST and most reliable way possible to know what your battery is actually doing is to use a Throttle% timer. when I ran battery beepers back in the days when I first started I found I was coming down with near half a packs power unused and wasted. Then when I started flying harder I was killing packs because I had to set the beeper too low for easy flights and by the time the beeper popped off the batteries were super hot and cells were puffy on cheaper packs.

Since I started using throttle% timers on everything I fly My packs come down and go back on the charger at near the exact same voltage both total and between cells every time. It doesn't matter if I fly the pack like an old lady out on a Sunday drive or rip around flags with my antennas on fire. SAME every time. I have not killed a pack since I started using this method only when they get crash damage do I need to retire a pack. this also works to keep the chemical balance relatively even in the packs life span so the internal resistance creeps up not sprints in some cells but not others due to poor heat management from over work.

Yes its a pain to find that exact point to set a timer and you need a different timer for every pack type and size but once you dial it in your packs come down the same way EVERY time now matter how you fly.