Rx Battery

Hello fellow forumites,
I have Futaba 2.4 ghz gear in my wot4 with 5 servos, i am using a 4.8v 1200 mah ni-mah to power the gear, at the field i use a battery checker that has a kind of traffic light system on it, after only 4 flights the checker would be showing orange. Thinking i might have a dodgy battery i bought a new one ( 4.8v 2000 mah ) but it is still the same.
I know my battery checker is working correctly as i have used it on other peoples models at the field.
If a servo was under strain would this cause the battery to drain excessively?
Any other ideas?

Thanks Dean

Cant say I like the traffic light system checker Dean. I had one on one of my models, which was a perminant fixture. I only had to taxi out and all 4 lights went to orange straight away!! I much prefer the "Battery Doctor", a small unit the size of a fag packet and about £20. Takes all the guess work out of the job.

Garry

Thats the type I use Dean tells you the voltage in the battery much better,and the percentage of power left

The more load that goes on a servo, the more current it will draw ... this applies to any motor.
A simple thing like tight snakes, hinges or linkages will cause this.
The problem with battery warning indicators is that they are just not very accurate & change depending on the temperature.
Battery voltage is also very dependent on temperature.

Typical voltage on a fully charged & warm Nimh may be well over 1.3V per cell (5.2V) for the Rx pack, & this may turn on the green light.
The same battery when out on a cold day may drop to 4.8V & only light up the "OK" indicator, even though it's working fine & fully charged.

Avoid high capacity batteries for Rx packs as these can't always supply a high current drain ... You'll find out about this when you drive all servo's at once & the battery voltage suddenly drops because of its higher internal resistance ... keep the bin bag handy !

After the crash you'll check the battery voltage & it'll be fine because it's not under heavy load.... You'll blame the Rx first, then interference, then possibly pilot error ....

If you're going to have a lot of servo's or high power servo's then the best thing to do is use Sub C cells or a 2S Lipo & a voltage regulator.
The Sub C's can supply a higher current without losing as much voltage.

Pol.

This is the battery checker I use,you can see the difference in percentage of charge from a newly charged battery to a used battery and some batteries that have been standing around, Charged up Needs charging

Thanks for all the replies.
If i am reading and understanding correctly the 2000mah battery i bought isn't ideal for my set up?
My charger shows the voltage of the battery pack would it be ok to use that as a more reliable way of checking the pack after flights or should i just get one of those display type checkers?
would there be a minium voltage reading where you would say "no more flying" or is there more to it than that?
Thanks
Dean

Some very good 2000 packs may be up to the job but I like reliability & plenty to spare. I personally wouldn't be very happy.
Your charger may only measure the voltage when it's switched on.
I'd invest in a very cheap digital multimeter ... they come in handy for a number of things & you can buy them for about a fiver now.
I paid over £300 for a posh one 30 years ago.

Just shout if you want any advice choosing one.

Pol.

SHOUT

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The Beard wrote: SHOUT

A simple little gadget like this is all you need to check battery voltages .... & much more.
There's a whole selection on ebay ... don't pay silly prices unless you do a lot of electronics, then you need a very good one.

I have just bought one of them from ebay Pol, i hope i will know how to us it

Very reasonable price