Transmitter battery

[john333]

Hi all, I have recently bought a nimh transmitter battery for my 3VC.
It's a high capacity one which I would have thought would last a couple of weeks at least.
The thing is the on board volt meter reads 9.8v when first charged but very quickly drops to about 9v and then stays there for ages (it's a 9.6v pack by the way) Is this correct?
I only have the Futaba charger to charge it with so takes an age to charge up from flat, will this damage the pack?
Finally, do nimh cells have a memory like nicads do? i.e. should I let the tranny go flat every few weeks, or just keep topping it up?

Thanks, John

[super__dan]

Honestly I'd invest in a lipo, mine lasts literally months without charging and as it has a higher voltage in the first place you know there isn't any signal strength issues.

[john333]

yeah, I was wondering about that, it would solve all the anxiety of wondering if the damn thing will start beeping half way through the final!! hehe

[fidspeed]

sounds like your tx pack is lazy fully charged you should see around 11v

yes it will drop but fully charged should last a while can you cycle it on your main charger ?

admittedly lipo is the best solution though !

dave

[bodgit]

Get yourself some of these, £11.70 posted

http://cgi.ebay.co.uk/TX-Pack-9-6v-N...item35a21667ba

make yourself one of these .
http://www.oople.com/forums/showthread.php?t=60418
I use one to charge my 3vcs. You can charge at 1c from your charger in nihm mode instead of the futaba,s trickle. You can give you tx a decent top up between heats during meetings if needed.

[john333]

Hi Bodgit, that's what i've got. My charger doesn't have nimh capability though. As posted above it may be a dodgy pack, but I'll give it a few cycles.

cheers, John

[Big G]

I have a £20 lipo from HK in my 3VCS and it lasts for 16hrs of use before needing a charge.

I remove it from the tranny and balance charge it with my normal charger. Takes the same time as the car's lipo to charge at 2.3A (1c)

I found with mine once the voltage got to 10v it dropped very fast and cut out (if anyone remembers the Ledbury 2wd regional my car just stopped dead in the middle of the straight lol) so the alarm never goes off. I just tend to charge it back up when it gets to low 10's. Full it reads 12.6v

[john333]

Thanks Big G, mine has never cut out as yet, suppose the other thing to do would be to check the meter on the tranny, or at least check the batt with a volt meter just to make sure I'm not getting any false readings (before I buy a lipo!)