Spektrum DX7 Eneloop NiMH vs Lipo

[StreetDragster]

Hi All,

Up until recently, i was going to change the voltage regulator in my DX7 and then install a 11.1v Lipo in it. Idea being that i can charge it up once a month and not have to think about its charge state if i get called up for a flying session at short notice (like at the weekend).

A friend of mine is well into torches and such like, and described to me the new Sanyo Eneloop batteries, which appear to be perfect. NiMH's that have low self discharge (like lipo), larger capacity than the stock battery (2000mah vs 1500mah), cheaper (£25 vs £35 lipo) and at 9.6v no need for a voltage regulator change inside the transmitter.

So, history has shown me that if something seems too good to be true it usually is, so i thought i'd ask here first.

What are the pros and cons of eneloops vs lipo? And is there anything i've missed?
If i installed an eneloop pack, i presume the standard spektrum charging lead can be used? Charge rate is estimated to be around 1.6amps (0.8c)

Thanks

Matt

[crash-alot]

Pros for eneloop. It does not discharge itself. Maintains its charge for up to a year.
Safe to use compared to lipo. 500mah more than the stock spektrum battery.
You can recharge up to 1C. I recharge at 0.5C for safety.

BUT also consider an even better battery. Sanyo's Nickel Metal Hydride battery. HR-3U-4BP(2700 mAh)
HR-3U-4BP(2700 mAh) - SANYO EMEA
This battery is currently the best AA size battery for use in camera application! So it will certainly do the job in your TX.

http://www.candlepowerforums.com/vb/...ad.php?t=79302

Currently sold by Midland Helicopters
http://www.modelhelicopters.co.uk/ac...ad_TxPack.html
and E-Flight
http://www.e-flight.co.uk/shopexd.asp?id=740

BTW. using any battery other than the original battery CAN be seen by Spektrum as violation of its guarantee.


Jaco

[coptermanic]

I hate having only one of any battery, so, after a forum debate on NiMh batts, I ordered one of these 9.6v 2100mAh Vapex batts:

Low Self Discharge

[StreetDragster]

I hate having only one of any battery, so, after a forum debate on NiMh batts, I ordered one of these 9.6v 2100mAh Vapex batts:

Low Self Discharge

Thanks for that link, aswell as the batteries you mention i see they also have the eneloops with the spektrum connector, and option not avalible from overlander, where i was originally going to get it from (And £5 cheaper too).

Do you have a link to the forum debate on nimh's? They are certaining appealling at half the price of eneloops.

No guarantee's to worry about with my DX7, its well out of its warrenty period.

Cheers for the Link to the Sanyo EMEA's, if i understanding the uber overwhelling graphs on the candle power forums, they are better than the eneloops for high drain devices, but the eneloops seem to hold charge better? I which case, i think the eneloops may still be the ones for me, as minimal charging is the aim for me.

[crash-alot]

Cheers for the Link to the Sanyo EMEA's, if i understanding the uber overwhelling graphs on the candle power forums, they are better than the eneloops for high drain devices, but the eneloops seem to hold charge better? I which case, i think the eneloops may still be the ones for me, as minimal charging is the aim for me.

You want more Mah really. If you use your TX alot than you will benefit more from a battery with a higher Mah. If you use your TX only once in a while then the Eneloop will be better for you because it will not self discharge as quick as normal batteries.

[coptermanic]

Will look for the link..................


http://www.rcheliaddict.co.uk/batter...o-voltage.html

[shikari_chaos]

Nice work guys, this is great info to have!
I've kind of been annoyed lately at the speed my transmitter pack looses its charge!

[StreetDragster]

Will look for the link..................


http://www.rcheliaddict.co.uk/batter...o-voltage.html

Thanks for the great link, after reading that i'm going to go with the vapextech instant pack, probably from ebay, £11 delivered with the spectrum fitting.

Just the one for now, and i'll have the standard spektrum pack as a backup.


Just one more question, i see it says that its maximum charge rate is 1.2amps (0.6c), will the standard spektrum wiring (internal to the transmitter) cope with this charge rate? Or should i put a fly lead on with a deans connector?

Thanks

Matt

[Sesame]

I dont mind so much it losing the power as you use it what annoys me is not using it during the week and then having to recharge the next weekend because the voltage has dropped so much.

So im thinking the eneloop could be a good compromise.

[crash-alot]

If you use the Spektrum charger, you will be charging at 150mah which equals 14hours charge time. No problem chargin them with the standard charger inside the TX

Thanks for the great link, after reading that i'm going to go with the vapextech instant pack, probably from ebay, £11 delivered with the spectrum fitting.

Just the one for now, and i'll have the standard spektrum pack as a backup.


Just one more question, i see it says that its maximum charge rate is 1.2amps (0.6c), will the standard spektrum wiring (internal to the transmitter) cope with this charge rate? Or should i put a fly lead on with a deans connector?

Thanks

Matt

[StreetDragster]

If you use the Spektrum charger, you will be charging at 150mah which equals 14hours charge time. No problem chargin them with the standard charger inside the TX

Sorry, should have been more clear in what i meant.

I have two chargers, the spektrum 'trickle' charger and a normal charger i use for all my other batteries.

I'm thinking that i'll have two scenerios in my modeling, the normal setup where the trickle charger is used mid week, and the battery is slowly charged up, no bother.
And the emergency setup, where the battery will need to be charged up quicker, probably all the way up to 1.2amps, or 0.6c.

So, in the emergency scenerio, would i be ok to use the normal spektrum charging point, with a 1.2amp load, or should i put a deans connector on a fly lead of the battery pack, and fast charge it that way?

Matt

[StreetDragster]

I dont mind so much it losing the power as you use it what annoys me is not using it during the week and then having to recharge the next weekend because the voltage has dropped so much.

So im thinking the eneloop could be a good compromise.

Ditto, but it seems the Vapextech is very similar in low self discharge to the eneloops, 100mah bigger, and 50% the price, which is the reason i've gone with them

Thanks

Matt

[Rctintin]

Sanyo 2700NiMh for me, lasts so long between charges (like 2 months) and that is with me flying most evenings 1/2 hour the MSR. (I do have the better voltage reg on my Tx though, and that almost doubles the battery life between charges)