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Hobby King Battery Monitor 3S

Hobby King Battery Monitor 3S

Hobby King Battery Monitor 3S
This unit will give a warning buzzer when the Lipoly pack drops below 9v.


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 Customer rated
Total of 33 discussions.
Chadd  1 points - 4/2/2014
does this work with a kk2.1 board if so how do i hook it up or does the buzzer that comes with the kk2.1 for the voltage alarm thats built in im new to all of this haha
 anikeev 978 points
It does work with anything :) You need to connect it directly to battery output - main or balance connector - in parallel with your other stuff. As soon as this unit detects low voltage it starts blinking and when voltage is super low it starts buzzing.
Slaveconstruct  8 points - 12/28/2013
DiegoVieira  6 points - 7/8/2013
Sokonomi  334 points - 4/22/2013
Is there something you can do to get this alarm to go full alert at 9v? Because if it beeps at 3v per cell, there's still plenty of time for me to plop down my quadcopter before it drops down to 2.8v. Currently it starts its full on whining at 3.4v already, which is way too soon for multicopters. My lipo meter keeps saying the packs are still half full when I land, and they are 45C packs, so something is up with these monitors..
 kanga 1055 points
YOU SHOULD NEVER GO BELOW 3.7 VOLTS PER CELL ! There is nothing wrong with the monitors .. they are spot on. Going below 3.7 will severely shorten the lipo's life, Personally I set all my alarms to trigger at 3.8 volts per cell . Might sound high but all my lipo's are over 4 years old and still as good as the day I first bought them .
 Sokonomi 334 points
At nominal voltage? That's just silly.. I STORE them at that voltage. Lipo only experiences real damage below 2.8 volts. And at 7 dollars a pack, who really cares if they last 3 or 4 years. I'd rather stay in the air 3 minutes longer on every pack, than save me 50 dollars every half a decade. *)
 kanga 1055 points
You may change your mind when you start paying $94.00 each for nanotech 6s , one bad discharge and its 100 bucks in the bin . I dont know about you but I don,t have money to throw away, so a bit of care does not hurt. I have approx $5000.00 tied up in lipos so I don't want to replace them in a hurry for the sake of a couple of mins flying :)
 Sokonomi 334 points
With big packs you are understandably a bit more careful, but only discharging to nominal voltage is a bit overprotective imho. Ive got a few 3s 2200 packs that have lasted me 3 seasons of weekly use running down to about 9.6v sofar, and they are still within margin (my indicator to packs going "bad" is when capacity is less than 90% of label).
Alex  4 points - 4/6/2013
Customer Reviews
Overall Rating
53 thumbs up!
Works well. Nice to know when your battery is running low.
This is a very cheap insurance to protect your large investment into the plane and batteries.
Keep you, your plane and spectators safe.
You do need to solder your own connectors it comes as you see in the picture with no manual. Just solder the 2 wired to the two outside pins on the connector matching plus and - and you are ready to go.

It is of a limited value if you have an EDF plane or fly in the area where EDF plane is preset. The signal is just no loud enough to pick up over the roar of the EDF. You'll have to do a no power, low altitude fly-by to pick up the siren.
The warning LED is small and unless you fly in the evening or have eagle eyes you will not see it in flight unless doing a slow fly-by.

It is very good for small GWS or 3d Planes that fly quiet or very close to the pilot.

I also found the plug to be fragile and it broke with in 3 uses so I just plug the wires directly into the battery.

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Overall Rating
Sam I Am
41 thumbs up!
This is a great item. It works great and is at an amazing price. I would defiantly recommend this to everyone. It is a must have for all hobbyists. No one wants to lose their plane just because their batteries were to low. I did once and learned from my mistake. I bought this and it works great.

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Overall Rating
37 thumbs up!
Good lipo monitor I have one on my every model. Why 4 stars only? Small differences in alarm level. But it's a must have for every LiPo user

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Overall Rating
Panayotis Pantazopoulos
28 thumbs up!
In my opinion this is a good accessory for all the electric slow fly planes and 450 size helis.
You can see and hear the warnings, so you know when you have to land.
The led is not very very bright and the buzzer not so loud, but for the price is the best you can have. For helis and foam planes i think is best.

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Overall Rating
Blue Angel
21 thumbs up!
The Maxpro Battery Monitor is a good device to monitor your lipos.
But i think it is a little bit too quite to use it in an airplane or helicopter. So, you have to fly near to hear the beeps.
I uses this monitor in series with an diode to monitor my 3s transmitter lipo. So it beeps at about 10,5 V.

There is a led on the monitor.
above 11,0V its lighting blue
10,0-11,0V its blinking blue
under 10,0V its lighting red
under 9,8V its beeping and blinking red

current draw is really small, about 5mA.

so, because of the not so loudly buzzer => 4 stars

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