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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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Weight: 30g
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Price $3.99

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Stock usually arrives every 10-25 days.
 Customer rated
Total of 39 discussions.
Sergeev  2 points - 9/23/2014
The monitor controls the entire battery or each element separately?
 anikeev 1227 points
It controls the entire battery.
Dmitry  20 points - 5/20/2014
What dimensions of this device L x W x H (mm)?
 anikeev 1227 points
PCB lengh is 26mm, but with speaker it's 30mm, W is 11mm and H is 1 or 2mm just PCB and H with speaker is 11mm. Hope that helps.
Ken  8 points - 5/13/2014
Anikeev, good one thanks. Maybe an engine and fuel tank is easier after all.
 anikeev 1227 points
It depends on model type. Almost every ESC that can be bought here have "low voltage cutoff" function. My rc-car (turnigy mini rally 1-16) runs much slower when battery voltage is letting low and ESC cutoff function activates to prevent deep discharge. I use this monitor on my quad where 2 separate batteries used for main motors, control board, FPV-equipment, LEDs and other stuff. I also use this monitor with my TX because it doesn't have any LEDs and I always forget to switch it off :)
Ken  8 points - 5/12/2014
With this monitor is the plug supplied soldered to the monitor cables and then the plug connected to the battery charging cables (two of). So that monitor can be used on multiple batteries? Thanks.
 anikeev 1227 points
This monitor comes without any connector. You can solder it to JST-XH connector so it can be plugged to any 3S battery with balance port. JST-XH should have 4 pins (for 3S battery) with 2.54mm between pins (thats exactly what XH means). If you will use this monitor on RC-car I recommend to cover it (except buzzer hole) with hot glue so it will not get crazy because of water. Hope that helps. BTW, check this item (SKU: 258000016) - that's white connector is actually what you need. It's on backorder here but you can buy it in your local electronics store.
Ken  8 points - 5/11/2014
Hi Anikeev, All this gear is new to me. My stuff is all mech. Thanks
 anikeev 1227 points
You can ask anything about everything in discussions - hobbyking pays 10 cents for each best answer (you choose what is the best) and all questions shows for people who already own a pruoduct so you'll get good answers really quick.
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

3 comments. Reply..

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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