OPTIPOWER INTELLIGENT BATTERY BACK UP

To date, all my petrol models have relied on a single 5s NimH pack and heavy duty latched toggle switch from SM services and i have never experienced any issues. However, i'm mindful to think some form of back-up power would be desirable. I've considered fitting two battery packs (one in each battery power socket on RD 921 rx ) but in the event that one pack fails shorted the second pack is also taken out unless Schottky / Silicone protection diodes are installed but this also introduces failure points. The obvious solution would be to instal a Power Safe rx & twin battery packs and this is the route i would definitely take on new purchases but for the time being i have a perfectly good RD 921 rx installed and am looking for a cost effective solution.

My inquires have led me the the subject unit as a possible solution. The manufacturer has advised me that a couple of the UK's F3A guys have adopted this system but i would be grateful if anybody has any experience or knows anybody with experience on this product so that i can have more confidence
www.optipower.co.uk/Catalogue/Products.a...0%20Back-up%20System

Kevin, the principle seems to be a simple lithium buffer battery pack that is initially trickle charged from your main battery pack (i.e. it sucks power from the Rx pack when it is first connected). If the main battery pack voltage dips at the Rx then the buffer battery pack is forward dioded to prop up the voltage. The guide doesn't say whether the indicator led's latch, so you may not know that a temporary voltage dip has occured during the flight. You may need good eyesight to see the led's which indicate that the unit is providing power.
Pro's:
Useful for propping up power surges.
Gives you a few minutes to land if the main pack fails open circuit.
Cons:
If the main pack isn't dioded off then this unit will waste it's energy feeding the main pack.
If the main pack shorts then you crash anyway
It can take up to 430mA from your main pack on the first flight
If it trickle charges then it is useless for the first few minutes
If it fast charges then it puts a fair loadf on the main battery pack

Kevin
SM used to make a battery backer which operated off two 6V packs. Presume this is still available,

Stuart

JRI wrote: Kevin, the principle seems to be a simple lithium buffer battery pack that is initially trickle charged from your main battery pack (i.e. it sucks power from the Rx pack when it is first connected). If the main battery pack voltage dips at the Rx then the buffer battery pack is forward dioded to prop up the voltage. The guide doesn't say whether the indicator led's latch, so you may not know that a temporary voltage dip has occured during the flight. You may need good eyesight to see the led's which indicate that the unit is providing power.
Pro's:
Useful for propping up power surges.
Gives you a few minutes to land if the main pack fails open circuit.
Cons:
If the main pack isn't dioded off then this unit will waste it's energy feeding the main pack.
If the main pack shorts then you crash anyway
It can take up to 430mA from your main pack on the first flight
If it trickle charges then it is useless for the first few minutes
If it fast charges then it puts a fair loadf on the main battery pack

JOHN - Thanks for your input - I have more info so will pm you

Stuartmck wrote: Kevin
SM used to make a battery backer which operated off two 6V packs. Presume this is still available,

Stuart

Thanks Stuart - Ive considered the SM services battery backer and my friend used one - they are still available but they common the outputs to one Rx power lead so full duplication is not provided. (pre duel battery input Rx design)

One concept which seems to be adopted stateside is to use two packs - one fed via a schottky with lower volts drop - the second (back up) by a silicon diode with higher volts drop . Then by monitoring your recharge values you have some concept of how the power packs are performing.