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Does the FPV receiver eat a lot of battery?

Discussion in 'General Discussion' started by Miika, Jun 25, 2014.

  1. Miika

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    I'm going to install 5.8ghz ImmersionRC UNO5800v2 with a single antenna to my RC-remote. I'm going to power it with a LiPo battery and would like to know what sized battery do I need to run the receiver for around 45minutes or so in a single run. So how many mAh:s does the battery need to have. Is 1000mAh enough?
     
  2. The Editor

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    From memory the current draw of the UNO5800 is around 250mA at circa 12v so a 3s 1000mAh will last you circa 1hr(ish)

    I used to use a 2200mAh 3s on my UNO 5800 (only because I had loads of them laying around) and I would fly for about an hour (but didn't bother turning the RX off between battery changes etc) and at the end of that I would put around 1200mAh back in the pack. So circa 50 - 55% after probably an hour and 20 minutes of the RX being on.

    1000mAh should be fine but be mindful of discharging the pack too low (below that magic 20%) since there is no auto cutoff on the 5800 (although there is a low voltage warning that can be set) and the RX will operate down to around 6v which would make that 2v per cell on a 3s and if you got that low your Lipo would be history.
     
  3. Miika

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    I could avoid killing the 1000mAh LiPo by attaching an "battery tester" to the balance cable... I have one that has an alarm sound when the voltage goes too low.
     
  4. The Editor

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    You can do that with the 5800 anyway - just set it up when you get it and once the voltage drops to your predetermined level it will start bleeping like mad!
     
  5. Miika

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  6. The Editor

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    That screen consumes circa 5watts so around 416mA at 12v.

    Therefore a 1000mah pack should give you around an hour (assuming discharge down to 20% of pack capacity).

    Using 2 x 1000mAh packs for your RX and screen should be fine. Of course if you find you are not getting enough time out of one pack or the other you can always get a bigger pack.
     
  7. Miika

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    I was almost "happy" when I found Turnigys 2700mAh batteries that had a great price and all... HobbyKings price for those was around 11€ / 15$ a piece. In Finland the cheapest 2700/2800mAh batteries cost around 38€ / 52$ so theres a huge difference in prices. Only one retailer here had some Turnigy batteries in stock, and the prices compared to HK were like 3-4 times the price. The problem ordering from HK is shipping costs that seem to be super high when it comes to shipping LiPo batteries. Shipping costs around 50€ / 68$ LOL. Although I understand that the shipping costs are high, as LiPo's are considered dangerous by shipping companies and I dont want to order LiPo's that are shipped inappropiately. Thats why I bought CE approved NextWaveRF 25mw transmitter :D hoping to get 300meters of video range with it (to stay legit)... If I would order maxium amount Turnigy batteries, I could "kill" the shipping cost in a way when there would be some sense in it... but then I would have like 10-20 LiPo's :D... I already have five Phantom batteries, but using two of those to power my receiver/monitor would leave 3 for flight and thats not enough. And even though oldest of my Phantom batteries will give me only 6minutes of flight time, I rarely use all of the five batteries.



    Either I have to
    The dream scenario A: I wil find some place that has lower shipping costs (appropriate shipping) and delivers the LiPos to Finland
    B: Take two of my Phantom batteries to power the FPV and replace those with those cheapo 38€/52$ LiPos... As a bonus I will gain some additional flight time
    C: I keep on flying with my stock batteries and buy two of those 1000mAh batteries that cost 15€ / 20$ in Finland.

    The idea of buying one battery with the price of four is the reason why I'm goooooooogling about cheaper LiPos.