Optipower Backup Guard

[PorscheBoy]

Question, I have set my Trex 700e up with a Gryphon quasar BEC (CC ICE2 120HV) and powered the BEC from just one of the 6S packs (this means I can do set ups without the risk of motor start).

Will this cause an issue in that obviously I connect one 6S up (which would put power on the BEC/Opti unit) then the other (12S setup)? I am assuming that as the Opti unit is measuring the BEC output, when I plug the second pack in, it should not make a difference or impact the Opti Unit initial voltage setting? Or would I need to connect my packs in a different order so that the BEC does not see any voltage until I plug the other pack in? Or am I being daft?

[Mark_T]

I'll go for the last option

Nothing to worry about that I can see. Your BEC is putting out the same voltage regardless of how many 6S packs you have connected, and that is all the Optiguard cares about ...

[mahbouni]

How are you measuring the voltage?

If you are using telemetry, is it Futaba or Spektrum, or something else?

Using a Multimeter

[Mark_T]

Using a Multimeter

A refreshing change from normal around here then

[PorscheBoy]

I'll go for the last option

Nothing to worry about that I can see. Your BEC is putting out the same voltage regardless of how many 6S packs you have connected, and that is all the Optiguard cares about ...

What? Me being daft? Oh, ok

[mahbouni]

OK I think i've got to the bottom of it now. I discharged the Opti Guard battery to 50% and then connected it again. This time it does charge and I get a flashing Red light along with a solid Green one. I left it charging until the Red LED stopped flashing and went out. Then I checked the Opti Guard battery again with my Fusion battery checker and and it was charged up to 89%. This explains why it didn't charge previously when I had already charged it to 90% with my CellPro 10S. I tried connecting a Jive 80LV with the BEC voltage set to 6V, but it still doesn't charge it any more. I'm wondering if it has been designed to charge up to only 89% to take into account cold weather. That would actually be a very good thing because the LiPo can get damaged if left out in the cold when fully charged. Or perhaps it just needs an even higher input Voltage to charge it more than 89%. I might try powering it directly off a fully charged 2s LiPo. But before I do that I want to find out how low it will discharge before it starts charging again. Previously I had manually charged it to 90% with my CellPro 10S and there was 72% left at the end of 4 flights. This tells me that it doesn't actually keep topping it up all the time and it probably kicks in at some minimum threshold. I'm going to leave it on and periodically check to see when the Red LED starts flashing again.

[PorscheBoy]

Mmm, I thought it was supposed to stay fully charged (from your flight packs or Rx pack) to ensure you have maximum available voltage/time to safely land, especially with the current/voltage used by the HV servo's, no?

[wadders248]

Just checked my pack voltage and it's at 7.8v, so it's either not charging, or there's a 90% limit?

I'm using the BEC at 8v from a Kosmik 200... also the LED is on constant when I first power-up?

[mahbouni]

OK just did some more testing. I don't think it discharges the Opti Guard battery when left on unless you force the BEC voltage to drop at least 0.5V below what it started with. So what I did is power off the ESC and I wiggled the Tx sticks aggressively to make the servos draw more current. Periodically I unplugged everything to check the Opti Guard battery voltage and then started again to discharge more. At no point did it ever start charging automatically. Well at least I never saw a flashing Red light while I was wiggling the sticks. It was only when I had discharged the battery to about 70%, powered everything off and and initialized everything again that it started flashing Red again. So unlike a 4 cell NiMh buffer pack which would continuously charge off the BEC, this unit seems to only start charging when you initialize it.

[Mark_T]

This makes sense.

I can't find it in the manual now but I vaguely remembered something about a limit and I found it mentioned in the original sales description.

It says there is a limit at 8.1V on the recharge which would equate to the 90% that is being reported.

[mahbouni]

This makes sense.

I can't find it in the manual now but I vaguely remembered something about a limit and I found it mentioned in the original sales description.

It says there is a limit at 8.1V on the recharge which would equate to the 90% that is being reported.

That's fine because in cold weather you don't want to charge above 4.1V per cell. You will damage your cells if you do.

I did expect the charger to kick in automatically during flight, but thinking about it I can see how that might cause a problem. When you fly aggressively and force the BEC Voltage to drop by 0.5V the device stops charging and buffers the BEC. Then when you stop flying aggressively it stops buffering the BEC and starts charging the battery again. This could happen very fast and frequently. I imagine it would be hard for the charger to keep up. In this scenario you migh be better off with a 4s NiMh pack but then you have the inconvenience of connecting it and disconnecting it every flight. Some people use a switch. If you use a Jive or a Kosmik, it is unlikely you would ever drop the BEC voltage by 0.5V unless you fly like a maniac. From logs I have never managed to get it to do this. So if your BEC is very strong then you probably never have to worry about the Opti Guard battery getting low.

[Summa1988]

Im confused...ive bought a optipower guard to run on my goblin but not quite sure how to hook it up?? Im using a mini vbar, castle edge 160 esc and castle bec pro v2. But where do I plug it in.

RD - rudder servo
CH3 - swash servo
CH2 - swash servo
CH1 - swash servo
RXC - bec
RXB - esc (without white wire)
RXA

Do I y-lead the bec with the guard or esc?

[mahbouni]

I used a Y lead into Rx C but any of the other channels except Rx A are OK.

SERVO Y LEAD 10cm - UNI - BLOCK TYPE, Robotbirds

[ledfoot]

I just purchased 3 of these units without the external LED. I've been testing them on the bench and I have been able to make more than one of my machines turn on by moving the servos on the bench. The turn on seems very random and is being caused by a random spike of voltage being generated by the JR 8717 and 8717hv servos that I'm using. The unit sets itself to about 4.6 volts and the big issue is that when the unit gets turned on by the servos it cannot be turned off by the switch and the voltage regulator gets VERY hot to the point where it will burn your finger. I'm sure that a prolonged time in this state would result in the unit being damaged. The only way to reset from this condition it to unplug the lipo from the circuit.

I'm wondering if there is anything that can be done to adjust the turn on sensitivity of this unit.

[acidla]

Have read over the Freak that there is a new firmware if using the guard with an Rx pack. Is this true?

Here it is, post 202 Optipower ultra guard - Page 11 - HeliFreak