blue320
Flight lieutenant
Posts: 50
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Post by blue320 on May 5, 2012 6:44:50 GMT 1
hey guys,
i been using AA batts for my DX5e. I'm curious as to how you guys are making sure your AA's power don't go too low. I"m replacing mine after 12 1350mah lipos used.
Is there a way I can check my AA's power output?
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Post by geoff2474 on May 5, 2012 21:11:17 GMT 1
Hi Blue I use rechargeable AA batteries in my Tx and fly for weeks between checking. All I do is check the voltage of the pack. 8 batteries nominal voltage of 1.2 per cell. So as long as I have anything above 9.6 volts all is well. With a fully charged pack they read about 11.5 volts. I would say unless you are using very cheap batteries you are throwing away some good units. If you are using non-rechargeable they should be 1.5v per cell so anything around 12v should be fine Also I think most good Txs have a low battery warning built in. hey guys, i been using AA batts for my DX5e. I'm curious as to how you guys are making sure your AA's power don't go too low. I"m replacing mine after 12 1350mah lipos used. Is there a way I can check my AA's power output? |
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Post by flydiver on May 5, 2012 21:32:57 GMT 1
There are little lights above your trim switches indicating the approx. condition of your batteries.
You can fly it down to just about red. It may function in red but not for long.
The power use is ~150mA/hour.
New alkaline batteries have 2000+ mA > 2000/150 = 13 hours (maybe more).
If you use rechargeable the use depends on the mA size, quality, and amount of time sitting around. Very high mA claims for NiMh are generally bogus and crap ( over 2500mA DO NOT BUY).
If you do get NiMh just get Eneloops (2000mA + low discharge) and save your self some grief.
Checking voltage on rechargeable that are not under load is almost worthless.
New Alkalines = 1.5v
Freshly charged NiMh = ~ 1.3-1.4v but soon dropping to 1.3. They will hang at 1.2v for a long time (longer than alkaline).
The lights are 'tuned' for alkaline so even FRESHLY CHARGED NiMh may not give you a nice solid green and the fuzzy warm feeling that goes with it. That's OK, unless it drives YOU crazy.
Most better TX use NiMh so there's nothing wrong with that at all.
Unless you are flying those 12 lipo batteries for an hour each you are likely throwing away half to 3/4 of your TX power.
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blue320
Flight lieutenant
Posts: 50
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Post by blue320 on May 5, 2012 22:37:14 GMT 1
Thanks for the tips! Flydiver, you are a stud. I found a DX5e manual online and there it is... "When the battery voltage drops below 4.7 volts, an alarm will sound and the voltage LEDs will flash."
I feel a little bad for changing AA batts frequently but the good thing is that I didn't throw them away. It's the pack rat in me. I'm feeling more confident now with my TX batts.
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Post by flydiver on May 5, 2012 22:44:14 GMT 1
You can use them in something else that won't matter when the batteries croak I suppose.
I almost never use alkaline anymore in anything. I am slowly switching over my old 'regular' stock of NiMh (as they die off-which can take a LONG time for the good ones) to the newer LSD NiMh like Eneloops. They are GOOD batteries.
FWIW a rechargeable doesn't go 'dead' until ~ 1v. At 4.7v alarm (4.7/4 = 1.175v) which is plenty of power left for landing the plane. You should be able to fly safely with NiMh until the red light. Do not do that with junk batteries. There's a LOT of difference between good and lousy NiMh and Marketing BS is not good criteria.
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Post by ginginho on May 8, 2012 9:07:22 GMT 1
You can use them in something else that won't matter when the batteries croak I suppose. I almost never use alkaline anymore in anything. I am slowly switching over my old 'regular' stock of NiMh (as they die off-which can take a LONG time for the good ones) to the newer LSD NiMh like Eneloops. They are GOOD batteries. Yep, Eneloops (well the Sanyo equivilent) in my Dx6i. One charge lasts ages and they don't drop charge (significantly) when not in use. Well worth the investment. |
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blue320
Flight lieutenant
Posts: 50
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Post by blue320 on May 8, 2012 20:56:36 GMT 1
thanks flydiver and ginginho. i did not know about eneloop batteries. i'll check them out and get a pack. this should save me some $$.
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Post by flydiver on May 9, 2012 0:07:20 GMT 1
Costco is one of the best places to buy them if that's available to you.
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blue320
Flight lieutenant
Posts: 50
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Post by blue320 on May 9, 2012 0:37:46 GMT 1
nice! yeah we have costco in north california. i'll get them this week. thanks for the tip!
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