View Full Version : battery upgrade options
teamkrazy
11-22-2007, 06:09 PM
hi all,
i am looking to put a better batttery into my dx7, i have looked thru the sticky about putting in the flightpower one,
are there any other options?
BigVanVader
11-22-2007, 10:39 PM
www.infinamodels.com (http://www.infinamodels.com)
Rodney has a great Ion transmitter pack for the DX7....slides right in and lasts a long LONG time between recharges.Ive had mine for 2 months now and have about 12 hours on it since it was installed,my voltage is still at 11.5 and the stop fly voltage is 10.8
I'll bet I can get another 10 hours before I need to recharge.
kamtsa
11-23-2007, 12:00 PM
Rodney has a great Ion transmitter pack for the DX7....
This battery does not work with FMA Direct 4S and similar chargers that charge through the balancer connector, right?
Thanks,
Kam
teamkrazy
11-24-2007, 02:41 AM
i have decided to go with the flightpower evotx cell.
should have it in by next week
Pinecone
11-24-2007, 08:14 AM
You do realize that JR/Spektrum do not recommend or support using lipos in their Txes?
fiveoboy01
11-24-2007, 11:12 AM
Something I have seen some people doing is taking 8 rechargeable AA lithium cells(forget the brand, they're like 3300 cells, can be bought at wal-mart etc), soldering together with tabs and bending them up then using tape to hold them together so they fit in the tx. I really can't remember where I saw it now but it sounds like a good option.
th3tick
11-24-2007, 08:52 PM
This battery does not work with FMA Direct 4S and similar chargers that charge through the balancer connector, right?
That is correct.
John
th3tick
11-24-2007, 08:53 PM
You do realize that JR/Spektrum do not recommend or support using lipos in their Txes?
Aside from the fssssh-boom aspect of LiPos, is there any particular reason?
John
Pinecone
11-25-2007, 06:48 AM
The higher voltage is what they say.
I just don't see the need for a lipo with 2500 and 2700 mAH NiMH Tx packs available. Same voltage as stock, supported by JR/Spektrum, can use stock charge jack, don't need to balance, don't have to worry about burning up your Tx.
th3tick
11-25-2007, 10:53 AM
The higher voltage is what they say.
I just don't see the need for a lipo with 2500 and 2700 mAH NiMH Tx packs available. Same voltage as stock, supported by JR/Spektrum, can use stock charge jack, don't need to balance, don't have to worry about burning up your Tx.
For me, using a LiIon pack, the biggest savings is that when off, it just stays charged. I don't have to worry about charging it but once a month, and it almost always is at the exact same voltage when I turn it on that it was when I turned it off.
All that, and no worries about balancing or flame-out.
John
tukkus
11-25-2007, 10:55 AM
The higher voltage is what they say.
I just don't see the need for a lipo with 2500 and 2700 mAH NiMH Tx packs available. Same voltage as stock, supported by JR/Spektrum, can use stock charge jack, don't need to balance, don't have to worry about burning up your Tx.
I don't know what it is with my NiM and NiCad batteries but I can't get a fast charge out of them at 3/4C or even a 1/2C without a false peak.... I've broken them in at 1/10C and even 1/20C on some and I always get the same results(false peaks) when trying to charge at a higher rate.
With my lipo tx battery I charge at 3/4C, it's a 2500Mah pack and it takes under 2 hours to charge. With my old NiM tx pack that was 2500Mah's(pretty sure that was the rating...NoBBS battery) it would take 3-4 times as long at 1/10C and a higher charge rate would only heat up the battery and give a false peak. Not only that the battery only lasted 1 year.
Maybe I got a bad battery or it's something I'm doing wrong but all my other Nicad's and NiM all still going strong but at low charge rates which takes time....I'm liking the lipos more and more.
I forgot to add that I'm using a JR 6102 TX with a Maxamp TX lipo(2500Mah pack) with a built in balancer. I do take the battery out to charge but I really wouldn't call it much of an inconvenience.
I also wasn't aware that JR didn't recommend or support lipos so I guess I'll have to figure out something before i buy the 2.4 9303
Pinecone
11-25-2007, 12:04 PM
I just stick the over night charger in every few weeks. Not a big deal.
I am thinking about low self discharge NiMH batteries. They hold charge well when radio is not in use and they are safe for accidental discharge. Lipos will be dead if you leave your radio on by accident...
Pinecone
11-25-2007, 06:29 PM
That's the other thing. I do manage to leave my Tx on every so often.
th3tick
11-25-2007, 06:33 PM
That's the other thing. I do manage to leave my Tx on every so often.
I do too :arggg:, but it's incessant beeping has saved me both times. Fortunately, the pack as been OK recovering from 9V. Even better, I can then, if I need to, charge it at up to 1C and be in the air an hour later.
John
fireup
11-25-2007, 11:34 PM
That's the other thing. I do manage to leave my Tx on every so often.
Me too:arggg:. I sometimes left it plug in to my sim for a whole week. My self made 2500 NiMH have been working great for me. At $18 a pack you can't go wrong.
I switched to these recently http://www.eneloop.info/ they are amazing they hold their charge just like lithium batteries and work with the standard wall wart charger or any other nimh charger. They may be hard to find, check in the photo section of your electronics stores. You can purchase them online obviously, I got mine from Frys.
Another similar alternative are Rayovac's Hybrid rechargeable batteries http://www.rayovac.com/recharge/hybrid_technology.shtml
Be wary of the regular 2500mah NiMh batteries out there, energizers especially. The newer AA energizers are performing poorly they must have changed their construction process recently.