Turnigy Low Self-Discharge (LSD) NiMH AA's
 

A couple weeks ago, I picked up 5 of the Turnigy low self-discharge 2200mAh AA cells from my LHS. I really couldn't come up with an ideal LVC solution to use lipo in my DX3r radio, and didn't want to deal with balancing a lipo inside a radio anyway, so I figured I'd give these LSD AA cells a try.

Fresh out of the package, they read ~1.25v each. I used them for about 3 hours total and the total voltage fell only 0.1v over that whole time, which included actual runtime and storage. Normally, after a couple weeks, regular NiMHs would drop down around 0.5v just sitting on my shelf, let alone actually using them.

So, tonight, I decided to discharge them all the way and recharge them to see how much charge they take. Discharging took 470mAh out of the cells before they hit 0.9v/cell on my discharger at 0.5A. From previous experimenting, the DX3r pulls 127mA, so if I ran for 3 hours plus the amount taken out via the discharger, means they came out of the package at ~40% charge. A full charge at 0.3A (3mv delta peak) brought them up to 1.46v/cell, taking a total charge of 2323mAh.

I felt that 5 cells at 1.46v/cell is a tad high (7.3v total) to use in the DX3r, so I bled 100mAh out of them, which brought the voltage down to 6.9v (1.38v/cell), which is what my regular NiMHs came out of the charger at. Instead of doing this rather tedious charge-and-bleed process to keep them at a decent voltage, I think I'm going to go back to using 4 AA cells in the DX3r again. These cells hold more than their rated 1.2v/cell until near the end of their cycle, so I'll set the radio voltage alarm for 4.7v.

In short, these cells do what they say; they exhibit VERY little self-discharge, and charge up to more than their rated capacity. For people not wanting to deal with lipo in their radios, yet still want a fairly flat discharge curve and low self-discharge, these cells fit the bill nicely. Only time will tell about their longevity, but their cost is comparable to regular NiMh AAs, so even if they do have a short cycle life (no data to support this anywhere I've seen), it's no big loss.

I got them for my DX3R when they came out and I also have had very good results so far.

I use them in my Tactic 2.4ghz radios. The work excellent and are suprising how long they last without much drain!

I suppose the only way to charge them is to leave them in the TX and charge thru the TX port?

I use a one of these. I put a Rx connector on this and then just charged them at 1 amp.

I rewired the stock radio jack and charge through that. These cells don't seem to like much more than 0.5A charge rate though; the voltage jumps too high for my liking. I figure 0.3A (~0.1C) is a good rate even though it does take around 7.5 hours. But these shouldn't need to be charged as often. The Spektrum draws 127mA, which means these 2200mAh cells should run it for around 17 hours.

Been using 2700mah Sanyos in my dx3r for 2 years now. they last forever with minimum self discharge. when they die will try turnigys

Sorry to go a bit offtopic but why were you trying 5-cell NiMH for DX3R?

Because 4 cell Alkalines is 6v, the same as 5 NiMH AA's...

Do you know if the DX3R has regulatad voltage for the RF part? Do you get more transmitting power if you have higher supply voltage, like the case is with "old" MHz frequency transmitters?

From another thread:

Anybody using Energizer lithium AAs? I've measured voltage as high as 1.82v on those?? I was surprised - I bought a bunch of them, they seem to last forever in txs and lots seem to be using them for rtr radios instead of fooling with rechargeables.

They're advertised as a 1.5v AA but the 100 I bought have all been much higher than that.

Those energizers are sooo expensive retail.

And with the LSD's, there isn't much "fooling around" anymore.

Guy on RCTechwas selling them brand new for 50cents/ea - all you wanted. Reason I bought 100.

Can I check if using the 4 x AA cells holder and charging it, how do I set the charger to charge them?