Where to get an eneloop pack?

[Chris_M]

Looking to put an 800mah buffer pack on my jive but where can I fInd these eneloop packs? Also read some people using regular AAA batteries but I didn't think they handle being charged for very long?

[fastflyer20]

Eneloops technology was developed by Sanyo, any NiMH saying "pre-charged" uses the same technology.

You can make you own packs (I did for my TX) or purchase packs,
Here is one source using the real McCoy:
http://www.radicalrc.com/category/Re...-NiMH-Packs-19

In my experince, they are way better than traditional NiMH

[Dumbthumb75]

You can buy ready-made eneloop packs here:

http://www.overlander.co.uk/batterie...rx-square.html

[bdbrown4764]

http://store.batteriesamerica.com/sanyo_3.aspx

[Chris_M]

Thanks for the responses. I dont really want to use one of those big Spektrum on/off switches if I dont have to, do you know of anything smaller thats easier to hide?

[Luisito]

If you go to Radio Shack you can find a battery holder for 4 AA Eneloop batteries and it has a tiny on off switch. That's how I did mine.

[wheelyking]

What's the purpose for using Eneloop batteries instead of regular NiMH batteries?
Is it just because they hold a stored charge longer? or is there another reason?

[fastflyer20]

They are way better, don't loose voltage in storage and when both are cycled, especially as they age, the eneloop are much closer to rated capacity

[Chris_M]

And do I have to power the rx with the packs first or use the buffer pack or does the order not matter?

[NewR]

Regular AA Alkaline WILL NOT work. They have the voltage and capacity but they have LOW discharge rate so they can not provide the current that the servos need.

I have a Nimh pack consists of (4) 1/2 AAA size batts (250mah ea) and they work very well as a buffer pack. Light and small.

I tested it with the following electronics for 3 mins with the heli on the ground (moving both sticks like normal fly) and it was still going when I stoped.

3 BLS451
1 BLS251
2 DSMX Sats
Skookum FBL
1 Cooling fan for ESC
1 Telemetry Unit

You can customize your packs here
http://www.cheapbatterypacks.com/

[Dumbthumb75]

Originally Posted by Chris_M

And do I have to power the rx with the packs first or use the buffer pack or does the order not matter?

Either order is fine, it don't matter.

I power up rx first with buffer, let it initialize, then plug in drive pack. In the same order as I would power up a nitro heli...

[Mystic3D]

Take this with a grain of salt, I read it but don't understand nimh well enough to prove.
Eneloop in this application is not the best choice as internal resistance is higher than a conventional pack, it will put excessive load on Jive BEC. Something to due with Discharge profile.



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[dl7uae]

The first question is, what is the purpose of such a battery: j-log.net FAQ

We should not confuse the particular purpose at a JIVE BEC with a different purpose of wanting to make an AR with a battery.

Tom

[desertstalker]

Originally Posted by NewR

I have a 1000mah Nimh pack consists of (4) 1/2 AAA size batts (250mah ea) and they work very well as a buffer pack. Light and small.[/URL]

Erm, if the half AAA are actually 250mah then you have a 250mah pack at 4.8V nominal voltage adds in series not capacity. That seems a bit small to me.

As to the internal resistance of Eneloops, it wont hurt the BEC, in fact its likely better for it as if the pack is a bit flat the charge current will be lower. A very small pack my however not be able to power the system should the BEC fail...

[KnifeEdgeUk]

Overlander batteries do eneloops.

[NewR]

Originally Posted by desertstalker

Erm, if the half AAA are actually 250mah then you have a 250mah pack at 4.8V nominal voltage adds in series not capacity. That seems a bit small to me.

You are absolutely right. I stand corrected. In series, capacity is of a single cell. It seems small but plenty for emergency as a buffer pack. Tested for 3 min like I posted earlier and put back about 110mah. Before this pack, I had the 125mah (4) 1/4AAA and was good for 15-20 sec to auto. 20s for an auto seems like an eternity.

[dl7uae]

........ No risk, no fun....

Capacity.... IR is the important thing and so the voltage.

You run a FBL system? Hopefully Vbar and no other, only Vbar comes back in-air after an undervoltage situation, stores the last calibration data for up to 10 seconds after a brownout.

And, there're some funny servos in the world, e.g. Savox, running into an endpoint even by a short untervoltage glitch.

----

JIVE: Short (250ms) voltage blackouts caused by back EMF prone servos (the monitoring processor in the JIVE cuts the voltage) can be filled even by very tiny packs.

Auro support is quite another issue, requires bigger packs of much lower IR.

Tom

[Chris_M]

I see that some people are running 4 AAA's as a buffer pack but that only equals 4.8V which is less than the jive bec outputs. Does the buffer pack have to equal the output bec voltage?

[wheelyking]

Hi Chris

I'm running a 4 cell AA buffer pack, regular NiMH cells. My 700 has been sitting for around three weeks. I just checked the voltage through the V-bar software and it read 5.4 volts. I have the Jive's bec voltage set for 5.6v When I top off the buffer pack and or fire up the Jive the voltage is 5.6v For me that's a decent voltage to run at.

[Chris_M]

Isnt that overcharging the cells though? If one battery is 1.2V and you have 4 thats 4.8V total. I would think you would need 5 1.2V batteries running on a 6V system or at least be running a higher voltage pack then what the bec is set at.