DX6i rechargable battery..

[Mike W]

It sounds like the club is BMFA affiliated and in the BMFA guidelines it states about having loose batteries in a TX/Rx situation , hence the need for using packs and not seperate cells

[Smoothound]

And the reason they won't allow ordinary batteries is? Is the club ran by a bunch of sandal-wearing cyclist environmentalists?

Nope they are just following BMFA guidlines...my club did as well

Sorry, I'm getting confused, you meant the same thing anyway

This is where I get another dollop of bad reputation from Big A for having a dig at the sacred organisation

[cotti]

I was always under the impression that it was because with a pack connected with a plug there was only 1 connection that could fail where as with single cells there were 16 connections that could cause a fail.

[Smoothound]

I was always under the impression that it was because with a pack connected with a plug there was only 1 connection that could fail where as with single cells there were 16 connections that could cause a fail.

I think you are right.

I'm sure all that is required is a soldered pack rather than separate cells but I think it is quite hard to get a proper pack in there.

Mind you I think the bulk of DX6i flyers are probably either back garden flyers and/or don't really care about what the rules are and just fly on their local park irrespective of the byelaws

[acwman]

I was always under the impression that it was because with a pack connected with a plug there was only 1 connection that could fail where as with single cells there were 16 connections that could cause a fail.

..actually, that would be two.. the +'ve lead or -'ve lead

[Mike W]

Phil .. I think you mean the idiots that fly with no insurance and give the hobby a bad name when they hit someone as they more concerned with there model than they are with people..The reason is like most have stated is loose packs have more chance of corrosion and falling out than a fixed pack .....

[Smoothound]

You could be right but...


Ask most modelers about how and why they setup their failsafe

90% will be trying to setup some sort of model saving slow circuiting method not thinking about who it might plough into on the ground

[Mike W]

True m8e .....

[cjcj1949]

My understanding regarding voltage on the Dx6i was that the Tx doesn't really care if voltage is starting to drop off (until it warns you of low voltage). What I mean is signal power being transmitted is not relative to volts available to the unit. I use 2700mah rechargeable's and they last forever. Having said that, I recharge them pretty regularly when flying, but leave them in when using Phoenix for ages and ages.

On the issue of using battery packs, I'm pretty sure what's been discussed before is the fact that packs are soldered together and then have a plug, as opposed to being held in by springs. This is what some clubs can be "funny" about.

The Tx isn't as well designed as that and abtteries are not that predictable. The new hybrio batteries hold their charge for a long time when new but only time will tell what happens when they age. NiCds and NiMhsdon't hold their charge very well on average and can discharge fully in a day even when new. I hadto buy 3 packs from Dixons a few years ago before getting one good pack. So when your Tx reads 5.0v its just the total volts and one of the cells could be flat.

There are two sides to the Tx pack question. If you use alkaline batteries that are new they will have nice clean ends and will all be the same. If you use rechargeables the longer you use them the more unreliable they get. If you have individual cells and check that they have the same voltage before charge then as a battery they will be more reliable than a soldered in pack which doesn't allow you to check individual cell voltages. But a good soldered joint is more reliable than a spring or friction connection as over time that will fail for a number of reasons.

The safest thing is to charge before using and to check your batteries after flying and make sure that the Tx lasts an hour or so longer. You will find that the Tx volts will fall slowly until the worst cell in the pack gives up. That could happen at almost any voltage. Then it will drop by a volt very quickly and after that all the good batteries will reverse charge the bad battery which will then get even worse.

Chris

[maderdog_1024]

why dont you just tape all your batteries together that way one cant fall out ?

if you use the re-chargable batteries then you can use the charging socket on the dx6i

and if you want to go over kill drill two small holes and fit some self tapping screws to the battery cover.

[mikalis]

batterys

hi all
going back 24 years when I started plank flying it was the norm with all bmfa flying clubs that only welded trans and rec packs could be used i.e no loose cells of any sorts hope this helps

safe flying
mike

[Pipistrelli]

Just for what its worth:

My son uses a DX6i to control a radio control car. Last summer the rechargeable AA cells in the Tx went flat during operation and for some reason the FS didn't operate and the vehicle just carried on, the car was recovered without damage. However, this was a car, not a Heli! I dread to think what could have happened!

I have noticed the battery meter doesn't sit very high even on freshly charged AA cells (just over halfway), so I modified his TX by soldering a BEC socket to the correct terminals and he can now use a small 2 cell lipo to drive it. There are 2 big advantages with this, the voltmeter now gives full deflection (which I think it was designed for), not half and there is no need to cycle the cells if the Tx has not been used for some time.

A small (1200mAh) lipo will sit in the battery tray without modification and with careful fitting of the BEC socket flylead, this can be tucked away so that AA batts can still be used.

A mod well worth doing, and the battery meter will show the pack voltage, so you will be able to avoid overdischarging. Ideal if you have spare 2S packs. They don't need to be high discharge either!

Please ask if you need more info!

[Mojo]

Thanks for all the replies guys..

I'll have to speak to them again and put some of the points you guys spoken about forward.. It does make sense that if they let me use single batteries it won't matter (concept wise whether they are rechargeables or not).. So i'll ask again.. All i have to do then is try to secure the battery cover and the cells together..

Ideally as you mentioned Chris i should check the batteries regularly before and after flying, and eliminate any dodgy ones, but in a way that defies the point of having them sealed in the Tx and using the recharging socket, as i'll have to remove them after usage and check them individually..

Maybe if they say i've got to use rechargeables i'll get an external charging unit.. And this way i can keep an eye on them..

I'll keep you guys informed about the outcome..

Cheers,

Mo

[Mojo]

Just for what its worth:

My son uses a DX6i to control a radio control car. Last summer the rechargeable AA cells in the Tx went flat during operation and for some reason the FS didn't operate and the vehicle just carried on, the car was recovered without damage. However, this was a car, not a Heli! I dread to think what could have happened!

I have noticed the battery meter doesn't sit very high even on freshly charged AA cells (just over halfway), so I modified his TX by soldering a BEC socket to the correct terminals and he can now use a small 2 cell lipo to drive it. There are 2 big advantages with this, the voltmeter now gives full deflection (which I think it was designed for), not half and there is no need to cycle the cells if the Tx has not been used for some time.

A small (1200mAh) lipo will sit in the battery tray without modification and with careful fitting of the BEC socket flylead, this can be tucked away so that AA batts can still be used.

A mod well worth doing, and the battery meter will show the pack voltage, so you will be able to avoid overdischarging. Ideal if you have spare 2S packs. They don't need to be high discharge either!

Please ask if you need more info!

Ahh.. That might be a an idea well worth the effort..

I'll have the talk with them, and if it's ok then i would do it..

It would be most helpful if you would send me some pictures to show me the mod.. I'll have to buy a suitable lipo though..

One question though, do you take the lipo out to recharge it or is it charged via the Tx adapter socket? (i can always use my lipo charger to recharge it)..

Cheers,

Mo

[Pipistrelli]

Mo,

Sacko has already PM'd me and asked for some photo's which I will try to do (asap) but at least over this weekend, on your thread.

You could charge in-situ, but you would have to use a prodigy (series type) charger set for 2 cells. However, it is much safer to remove the cover and balance charge the 2S pack seperate from the Tx. Also I can see no sense to further secure your batt cover. After all if the cover fell off the back of a FF9, or DX7, the battery would fall out and disconnect itself anyway, its plugged in, not hardwired.

I think this issue goes back to terminal corrosion that is more prominent with single cell type arrangements which can severely reduce battery voltage.