Buzzers and warning light

[T/CHunter2009]

Are these any good ?? I never used one , I'm wondering do any of you guys use these and how well do they work.?? When do they go off { BEEP BEEP !!! } at what voltage is your pack at when the 6s device goes off?? The reviews look good.

[TETE]

I'm using this one for the 6s.
http://www.maxprotechnic.com/Maxpro/.../MaxproBM.html
I'm very satisfied with this great monitor, the TX timer it's gone...

Tete

[dabar]

Find one that allows you to set the lipo alarm at 3.5v-3.6v.. Quite a few (2.8v-3.2v range) are no real good for use with lipo's as an optimal flight timer because below 3.4v under load (in flight) the battery has been over discharged.

Personaly I feel that a good unit is worth every penny, I'm happy to use mine (Spartan G4 set at 3.5v, LED only device) along side the Tx timer.. Tx timers are okay when everything is going to plan but [for example] lets say I mess up and reconnect a used lipo or even forget to activate/reset the timer; The alarm will make sure I know before any damage is done.

[T/CHunter2009]

Good point , thanks guys, I always check my cell packs with a little device I got from H/K. Just to make sure I dont mess up and do exactly that. I want to get a nice one , that one looks good to me. Thanks again.

[Larry227]

TETE I found that one at helidirect. Is it as bright as the picture shows? I might have to get one also since I'm always forgetting to start my timer.

[dabar]

Looking at the MaxPro, I notice that it switches from flashing blue to red solid at 20.4v. I've not seen any mention on whether if it works based on cell voltage or total battery voltage Total voltage is not ideal.

I found what looks like a pretty good device on www.fast-lad.co.uk, the LVS 32..
http://www.fast-lad.co.uk/store/lipo...av-p-4282.html

I did a search and got some links for your side of the pond :glasses2:

First though, I'll start off with an example image of the Spartan G4 which puts out 12000mcd(around 11.7 candlepower):


The Green/Emerald LVS 32 I gather puts out 22,000 mcd (around 21.5 candlepower), that's pretty darn bright! An optional audible alarm comes in two scales, 85 db or 105 db.. [EDIT: the LVS 32 uses the 105db alarm, the 85db is for the smaller 4s version].

Info:
http://www.electrotekrc.com/products.html
Manual:
http://www.electrotekrc.net/pdfs/Ins...0208%20pdf.pdf
Dealers:
http://www.electrotekrc.com/dealers.html

In theory, it owns the Spartan G4 and it's cheaper I wonder if we have any owners of the LVS 32 around here..

[Deet]

I use my timer, it auto starts off my throttle hold switch. Whwn I get the 10C I will do the Finless timer for it

[TETE]

Mine is from Hobbyking:
http://www.hobbyking.com/hobbyking/s...idProduct=7227
The LED's are very bright, I think, about the measurement of the voltage that is the total because only have 2 wires like the one from Electrotek.
When I had the Walkera heli I was using the GEM2000 from Electrotek, and it was great.

Tete

[doeLauw]

My dx6i timer sucks big time ... can't hear it. Using rclogbook on my iPhone. That just rocks loudly tells you the remaining minutes, vibes and counts down in the end. If you put in stats you get à perfect flightlog. Loving rclogbook.

[Steve Evans]

Originally Posted by Deet

I use my timer, it auto starts off my throttle hold switch. Whwn I get the 10C I will do the Finless timer for it

What's the Finless timer?

I initially set my 8FG's timer to run with the throttle above min, and reset with the long momentary (trainer) switch on the right. This worked for the first pack, but on a couple of ocassions I've forgotten to reset it for the second.

I've now set the second timer to start when throttle hold is off, and reset by the switch I use to set the gyro to rate mode. As I always toggle this switch prior to takeoff to center the tail, I'll never forget to reset the timer.

I think that the trick with timers is to make them trigger/reset using something that's part of your normal procedure.

Steve

[T/CHunter2009]

Finless timer ??? I know I I definitely want a good battery monitor so I don't over discharge my batteries. So many to choose from but I want to get a proven one and one that works by cell voltage not pack voltage. I have been known to forget to flip my timer switch and or push my aux timer button that is mounted on the radio. That sucks when that happens. I once flew my new 3300 brand new pack 8 minutes.! Not cool. It took the cells down to 3.71 That could have been bad if it wasn't for the high mAh rating.

[Santini]

The best one for the money is the bm-6 from hobby city. The reason being, you want a monitor with audio and you want it configurable.

Unless you are flying right in front of you, and not in full daylight, you'll never see the lights, so lights-only is pretty useless.

Next, you want it configurable for voltage per cell. BM6 lets you toggle thru the voltage and it will start screaming when you hit it. Its convenient too insofar as you simply plug it into the bal tap on the batt, slap on the canopy and go. It handles 2-6S; therefore, if you are serialing two 3S packs on a 500, just plug it into one of the 3s packs. It has a std pq connector on it, so just use the std to TP adapter if you have TP batts.

It is reasonably accurate, much more so than the inexpensive batt voltage readers. I tested several batts using it and then compared to multimeter and its pretty much spot on. Not kidding either, its plenty accurate. (Nothing like the cheapo voltage testers you keep in the flight box that are good only to tell you if a pack is discharged.)

Nice, too, is you plug it in, it starts cycling thru the cells, gives each reading, full pack reading, then max difference between high/lo. Also, I dont recall what the allowable variance is, but when you plug it in, if you have a low cell (as in a cell going bad), it will immediately alarm.

I have a 6 inch extention wire, so what I do is plug the bm6 into the extention, then that into the bal tap and strap it down on the pack (and the sounder just sticks out the top of the 500 canopy).

It is loud and you can be way off in the distance and trust me you will surely hear when voltage is the perscribed level. I would add that it behaves similarly to the HRPolyX monitor I have on my 450s, insofar as there is no false or momentary triggering you get with cheapo lipo monitors. (HRPloyX is a superb alarm, has other great features, I have two, but it is 4S max, and $29, so not inexpensive -- but it is the best alarm IMO up to 4S). Some of you may know what I am talking about where you increase load and a monitor goes off, and you let off the thrott, and it immediately stops, that is crapolla. The maxpro and little ones like people are referencing are toys IMO, and not good ones either, for hovering micros, and the votage trip is fixed and too low anyway.

Last bit, the main reason you want configuarable is your packs are not all the same in terms brand, chemistry, capacity, health and so forth. The idea is to terminate flight before the voltage begins to cascade. In other words, during discharge, voltage will be fairly contant (slight steady downward sloping voltage ourput), until close to the end of the pack when voltage, often about 3.5 v/cell under load, and it quickly cascades. This IMO is where the pack damage occurs. Having a confirgurable alarm enables you to target a specific voltage, before voltage sag. This is not to say you should not time, indeed, I set the timer to go off someplace ahead of where the voltage collapse should be on my 500, knowing I should be hearing an alarm sometime soon. Lately I have the bm6 set to 3.6v/cell under load, which is giving me about 3.75 or so resting going on the charger, the idea being to have a resting discharged pack go on the charger at >3.7v/cell. I find that using a configurable monitor sometimes surprises you where a pack alarms earlier than expected, and that's the whole idea.

Best news is its $13.

[Finless]

He is talking about my video on the Futaba 10C to make a timer that starts with the throttle stick.

http://video.helifreak.com/?subpath=...sticktimer.wmv

Bob

[jamesb72]

I've had loads of beepers/alarms and none of them are loud enough, until I found these 4S alarms which are superb, they are painfully loud even in flight on a 500 - they don't make a 6S alarm, but the 4S works fine, as you can stick them on the middle of the 6S connector, and monitor the center cells, which normally go weak first anyway as they have the least cooling.

IMHO you should still use a timer as your primary means to decide when to land, this is a backup to alert you to a weak pack, or if you forget to start timer, or accidentally fly a pack twice - it will screech at 3.3v per cell so loudly your ears will bleed even if its 200ft away from you.

Flying down to 3.3v/cell is not good for every flight so this isn't an alternative to the timer, but is enough to stop you before you damage anything, also it initially beeps when voltage drops below higher threshold and stops when pack recovers (ie full throttle climbouts on cheap packs, it will bleep at full pitch, then stop when you level out), then the beeper latches on below another threshold (not sure what voltage but 0.2v I'd guess) so you have to land to unplug the screaming banshee.

It is basically the best in flight lipo alarm I have ever seen or used and its cheap as chips.

You need this type with the 'loudspeaker' shaped beeper - example is item 260482880300 but there are loads on ebay around $5 delivered !!

[jauguston]

My Hitec Aurora 9 has a programmable timer (actually two) that I have the timer on set at 20% throttle. It is a count down timer and right now until I get used to how much battery drain I have I have all three helis 2-450 and a 500) set for 5 minutes. It beeps every minute and beep-beep-beep at 0. It also monitors airborne receiver battery voltage.

Jim

[freewheel510]

Got the Electrotek LVS 32 with remote LED mounted on my brandy-new 500 ESP yesterday. Rather than drill a hole in my 500 frame, mounted the LED to a bit of scrap plastic and CA'd both to the inside of one of all those holes on the right side of the heli.

Installation was easy. Stripped 1/4" of ESC lead-in wire and wrapped the 20-gauge (est) sensor wire around and soldered. Mounted the box inside frame just behind motor.

On initial test, which was the 12th pack I've run thru this heli, I used a pretty new (maybe used 5 times?) Turnigy "2.6" rated at 2650 mAh 30-40C. Flight time was over 7 minutes.

I hovered until I saw the light come on, and landed within 5 seconds, and when I landed the light went off. It was near sunset, and the sun was behind me, and the light was easy to see. Obviously, I need to try it in full sun as well, but I'm optimistic.

On recharging, my Hyperion charger reports putting 2560 mAH into the battery !!! Holy crap, that's 96.6% of capacity.

Is it possible my Turnigy battery has more capacity than I think? Or is it likely that the threshold voltage is set too low?

I plan to test the threshold voltage (i.e. where the light comes on) soon, and will report back.

[jamesb72]

IMHO anything which monitors the whole pack (ie not weakest cell) is a waste of time - for it to be safe you have to set the trigger voltage so high (to protect the weakest cell) you will effectively just ignore the warning as it will come on half way through your flight.

You need to monitor individual cells to alarm on the weakest cell - and you need to use this as a backup to a timer as your primary flight end trigger.

I fly 5min timer on my 500 with 2650mah packs and put back in about 1700mah so I am well under 80%, which means my packs should last as long as possible.

[freewheel510]

I wonder about that reasoning. If one cell is way weaker, isn't the pack toast anyway? Obviously, flying with a timer, which is the "tried and true" method, is real vulnerable to the "weakest link" approach, but if one cell is feeble, won't the pack drop down to 22 or so volts real fast anyway?

I got this monitor because a) all my packs are well balanced, and I hope to keep it that way, b) it doesn't take any extra steps like plugging in the balance connector (or setting a timer) to use, and c) I figured I could see the light easier than hearing a buzzer (my eyes are better than my ears!).

I've ordered the 4 cell monitor you recommended from ebay and will try it too. I ordered 2, one for the 250 which I'm sure I'll be able to hear, and the second for the 500 which I am skeptical about. Hey, if I can get a sub-$10 insurance policy for my $200 battery investment, it sounds like a good investment to me.

I really want to use voltage as my primary flight end trigger. I don't want to buy a Futaba or Hitec radio, which have the automatic throttle-triggered timers you describe. I think the JRs can do that too, but they don't shut off when the throttle drops below the trigger point, they just keep ticking. I have a hard time remembering to set the timer manually on my DX7.

But the main problem with timers is that it is a very indirect method of measuring what you want to base your flight times on.

Battery voltage is a less indirect method, and cell voltage is even better. The irreversible changes that cause battery failure are reflected by the cell voltage dropping below a certain voltage, like 3.6 volts, right?

[jamesb72]

Originally Posted by freewheel510

I wonder about that reasoning. If one cell is way weaker, isn't the pack toast anyway? Obviously, flying with a timer, which is the "tried and true" method, is real vulnerable to the "weakest link" approach, but if one cell is feeble, won't the pack drop down to 22 or so volts real fast anyway?

The pack may be toast, but if you get a beeper as soon as you take off, you can land your heli without that being toast as well - thats what the lipo alarm is for, as a last safety check to protect your heli, not your pack.

Flying to a voltage alarm is basically like flying to LVC - which is pretty much universally reckoned to be a bad idea, you are better off setting a conservative timer, I use 5mins and getting used to it and monitoring how much you put back into your packs on recharge and you can adjust timer up if your well under 80% consistently.

You get used to this time pretty quickly, so when I am flying around I pretty much know when 5mins comes up, and am normally thinking about landing just around the time the beeper goes anyway.

Remembering to start the timer just takes practice, you will soon get used to it, and if you forget - stop and land and change packs - that is the punishment for forgetting to start the timer.

I now start the timer as part of my spool up routing along with flicking gyro into rate and back to center the tail, so its pretty much automatic, I forget to start the timer maybe one flight in 20 and I just land and change packs and start the timer.

Seems for what your spending on lipo alarms, you could buy another lipo - which I think would be a better use of funds

[freewheel510]

Originally Posted by jamesb72

Flying to a voltage alarm is basically like flying to LVC - which is pretty much universally reckoned to be a bad idea,
...
I now start the timer as part of my spool up routing along with flicking gyro into rate and back to center the tail, so its pretty much automatic, I forget to start the timer maybe one flight in 20 and I just land and change packs and start the timer.

Seems for what your spending on lipo alarms, you could buy another lipo - which I think would be a better use of funds

I look at voltage profiles from data loggers,

https://www.helifreak.com/showthread.php?t=135664 << an example

and the voltage generally seems to stay pretty flat for most of the flight and then drop steadily after awhile. In the second graph above, there is a steady decline in voltage in the second half of the flight, with lower voltages during times of high current draw.

In the second graph above, the initial voltage is 12.5, on the 3S pack, for an average of 4.17 v/cell. By the end of the flight the hover voltage is 10.5, or 3.5 v/cell.

I hear what your saying about going to LVC, but I'm not looking to wring every last bit of current out of the lipos, and I"m ok with getting false alarms during maneuvers. And I definitely don't want a power reduction.

I'll work to get in the timer habit. I learned how to remember acronym checklists learning how to fly full size planks, so I should be able to remember "three T's" before takeoff: Tail reset, Timer start, Throttle hold off.

Regarding spending, it gets worse: I just ordered telemetry from HK. Crazy? Maybe, but I want to understand these LiPos and that seems like a helpful tool. So with that, yeah, I could have got a new pack: New pack: $50, Telemetry: $70, Knowledge: Priceless.

Cheers!