small flight pack charger

[Phil 9]

I have a 4 cell Nimh battery pack in my acro wot .

I was wondering if there was a small charger I could use to top it up at the field.

I have a power pack for my phone and wondered if there was something similar available for flight pack charging

[Former Member]

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[Former Member]

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[MattyB]

I have one of these primarily for RX field charging during long summer slope soaring away days. Powered by a 3S Lipo of 2200 or so it's small and light enough to carry to the top of even the biggest hills! Mine was an amazing £9 or so from the Int'l warehouse two years ago, but obviously with the devaluation of the pound they have gone up a fair bit since then.

[Former Member]

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[Phil 9]

**LINK**

searching around I did come across this one. costs a little less. any thoughts?

[Former Member]

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[Phil 9]

Posted by Percy Verance on 02/04/2017 22:08:19:

The specs would seem to indicate it's suitability Phil, but is it a little too cheap? It'll probably be ok, but hard as I try I can't get away from the old adage *you get what you pay for*. Still, at that price it's probably worth a punt.......

Edited By Percy Verance on 02/04/2017 22:08:48

model shop Leeds are selling the same item at £14.99

[Former Member]

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[ChrisB]

Phil9, whats the capacity of the RX pack?

[Phil 9]

I cant remember the rx pack capacity. it is buried under the fuel tank and not easy to access to change it. I think it may be 800mah

[ChrisB]

Ok Phil. I assume this is the standard Acro Wot I.C model?

If it is then why not buy yourself a higher capacity battery? Something like **LINK**

They are available as flat or square. I can get three 20 minute flights on a standard model with standard servos and at 1amp it still gives 4.7v.

For £7 its worth having.

CB

[Phil 9]

Posted by ChrisB on 03/04/2017 08:03:24:

Ok Phil. I assume this is the standard Acro Wot I.C model?

If it is then why not buy yourself a higher capacity battery? Something like **LINK**

They are available as flat or square. I can get three 20 minute flights on a standard model with standard servos and at 1amp it still gives 4.7v.

For £7 its worth having.

CB

I may have made a mistake and I think the one in the link is the one I have. about an hours flight time is about what I get now but on a good day that is not enough.

[Frank Skilbeck]

1 hours flight time on 2600 mah doesn't sound like very much, might be worth cycling the battery and checking it's capacity, We used to fly most of the day on a 600 mah Nicd, but then again if you are doing continuous high speed aerobatics then you could be consuming a lot of power.

[Denis Watkins]

Hi Phil, you know it is difficult to quantify how many flights we get from an RX pack, but on a good day, as you say, mine uses about 300 ma over about 4 hours having say 6 flights of that model, and checking and tuning period. The pack is a 2000 ma, so is no where near using the full capacity.

I would keep a constant check on your pack as when they go west, it is usually over a very short period

I would be tempted to finish using that particular pack, if it is reliably full charged but only useful for one hour, it does not appear to be up to the task anymore

[Denis Watkins]

Frank beat me to it

[Phil 9]

maybe what I really need is an acurate way of testing the voltage and to know what level is safe for more flights.

I may just be paranoid but I know it is a single point of failer and a loss of power will result in the loss of control of the model. it is not a big enough model for two power supplies

[ChrisB]

If you're in any doubt at all Phil, then change the battery for the one linked above. It's not worth risking a model or safety for ?7 and the agro of messing around with testing this that and the other. A basic battery load meter will do the job but change for a new one.

[Frank Skilbeck]

True, but back in the old days we used to fly with 600 mah 4 cell Nicd, charged off a 50 ma wall charger and fly all day, the only time I had a problem was when I decided to fly 2 days in a row without recharging but I must admit I've had mixed results with the high capacity AA Nimh cells (i.e. 2,000 mah +) some are OK and some won't hold their voltage under load, so I test them and only use the good ones and I'm migrating over to 2s Life cells now (or Sub C Nimh where they fit). But I do have Rx voltage telemetry on most of my planes.

[MattyB]

If you really do have a 2600mah pack and are only getting 1hrs running from it, then I agree it's due for the bin. What voltage is it sitting at after an hour of use?

Before you dispose though try this... discharge the pack to around 1V/cell, trickle charge it (0.1C charge rate) fully then run a bench discharge test on a servo tester (using 3-4 servos). This should give you a good idea or the real world capacity of the pack and it's behaviour under load.

Edited By MattyB on 03/04/2017 14:20:27

[Robert Armstrong 2]

Posted by Phil 9 on 03/04/2017 12:16:49:

maybe what I really need is an acurate way of testing the voltage and to know what level is safe for more flights.

The pack voltage is an unreliable indicator of remaining capacity for NiMh cells, as they decline slowly and then drop off rapidly when exhausted. Also, the packs tend to lose capacity as they age, so an old 'fully charged' pack as regards voltage may not have much actual capacity left. Best option is one of the batter checkers that applies a load to the battery on test. Fusion do one quite cheaply. Some of my models (those with clear cockpit canopies) have one of the voltage checkers with a row of LEDs plugged into the receiver. Before and after the flight, moving all the servos gives some indication of the voltage under load. My rule is 'top end of amber under load is probably good for one more flight only'. Anything in the red lets is finished for the day.

[Tim Cheal]

I use one of these to check my batteries befroe flight if I am in any doubt (and certainly before I leave home having been caught out once when I thought a bettery was charging when it wasn't!. It seems to work, but I am sure others will know of different products.

**LINK**

Tim

[Phil 9]

well after todays flying and after reading the replies here I can now see my rx battery is defiantly not performing as it should. It is relatively new so had previously thought that was not the problem

[Phil 9]

is there any advantage in using an eneloop pack?

[Denis Watkins]

From the horses mouth Phil, lighter, longer lasting, low self discharge

The Eneloop Lite 4.8v AA Battery Pack is a perfect pack for gliders, or any model where weight is of upmost importance! Weighing only 80g (compared to the standard 2000 eneloop weight of 110g). These cells are tough, powerful and will last approximately 2000 cycles. They are a perfect substitute for the 1000 NICADS, which are no longer available on the market. Sanyo Eneloop batteries are the best all round solution to a powerful long lasting non self discharging receiver pack.