New type battery ( LiFe ) ?

[HeliHolic]

I was looking at the e-Station BC-8 and see it will do these (LiFe) and I can't find much on them.

[RC Accessory]

I am the US Importer for Bantam. I would be more than happy to answer any questions. You can email me at evan_chapkis@rcaccessory.com or call me at 813-765-0124.

The BC-8 will do the Li-Fe as well as all chemistries.

[kgfly]

At the moment these are the only LiFe cells available. They come in one size only, 2300mAh and 70g each. You can see the details here: http://www.a123systems.com/html/products/cells.html

Do a search on A123 on the forums to see folks experiences with them.

They have lots of advantages over LiPo including:

* very robust (metal can package)
* inherently safe (will not burn on short circuit, overcharge or puncture)
* 1,000 cycle lifetime (at 10C discharge) down to 100% discharge
* high charge rate (up to 10A = 4C)

And disadvantages:

* nominal 3.3V, 3.6V fully charged (vs 3.7/4.2 for lipo)
* the 2300mAh cell is 70g, about 30% heavier than a similar capacity lipo

Other notes
* must NOT be charged on a LiPo or LiIon charger, you either need a LiFe charger (eStationBC6/BC8/e902, Cellpro4S or TP1010 with firmware upgrade) or some folk use a NiCd charger together with a Lipodapter set to A123 mode (not nearly as good as charger with LiFe support IMO).
* Don't believe everything you read. Field experience has shown that a realistic rating is 15C continuous, 20C burst, 30C blip and not their claimed 30C/50C. At 30C they heat up fast and cycle lifetime is severely reduced.
The cheapest way to get them is to buy a DeWalt 36V powertool battery pack on eBay , usually around $100. You then crack the pack for the cells and make up your own packs to suit.

Since the nominal voltage is lower than lipo, you typically need extra series cells. Hence to replace a 3S lipo you would use a 4S A123. Due to their weight, there is a tradeoff in voltage/power/performance. The weight and size penalty has less impact on larger helis. Thus for a TRex450 a 4S A123 weighs about 300g compared to a 3S 2200mAh lipo at 180g. On a TRex600 a 10S A123 at 750g is about the same weight as a 6S 4900 lipo. You get shorter flights on the A123 but for the same money you can have twice as many packs, they can be charged faster and they are much more likely to survive a crash. They may not be a good choice for wild 3D

[HeliHolic]

Thanks -- Evan and Kenneth, I'm only looking at chargers right now, I have both Multiplex Charger LN-5014 and Hobbico's Quick Field Charger MkII. The only Balance charger I have now is the stock E-flite 3-Cell Li-Po that came with the BLade CP Pro.

[kgfly]

If you only need 3S/4S then the CellPro4S is fantastic value at ~$60. An integrated true balance charger with LiPo/LiIon/LiFe support.

If you need up to 6S then the new BC6 is interesting, essentially a BC5 enhanced to 6S and with LiFe AND with an integrated AC/DC power supply. Now you've gone from potentially 3 boxes (power supply + charger + balancer) to 1. However the BC6 is only 50W output so charging large capacity packs can be slower than you might want. Which brings you back to the BC8+LB6 (150W) or 902+LB6 (200W) which is a competitor to the TP1010+210 (220W)

[RC Accessory]

If you only need 3S/4S then the CellPro4S is fantastic value at ~$60. An integrated true balance charger with LiPo/LiIon/LiFe support.

If you need up to 6S then the new BC6 is interesting, essentially a BC5 enhanced to 6S and with LiFe AND with an integrated AC/DC power supply. Now you've gone from potentially 3 boxes (power supply + charger + balancer) to 1. However the BC6 is only 50W output so charging large capacity packs can be slower than you might want. Which brings you back to the BC8+LB6 (150W) or 902+LB6 (200W) which is a competitor to the TP1010+210 (220W)

No need for the LB6 or optional balancer with the BC8. The BC8 has a 8 cell balancer built in.

[kgfly]

Doh :oops: Thanks Evan for clearing that up, I don't know why I typed "BC8+LB6", I know better. My only excuse is that it was almost 1am for me.

[RC Accessory]

Doh :oops: Thanks Evan for clearing that up, I don't know why I typed "BC8+LB6", I know better. My only excuse is that it was almost 1am for me.


lol.... :)