What is the cutoff point for lipo's
 

I'm using a 3 cell lipo in my DX-7. I don't put a full charge on it when I do charge. But, how low per cell can I go.
Don't want to get it to far down and ruin the battery.

RE: What is the cutoff point for lipo's
 

Why don't you put a full charge on it?....I run my LiIon's down to 7V with a 1 amp load then re charge....

RE: What is the cutoff point for lipo's
 

Guess I was afraid that the voltage would be too high for the TX. I normally shut it off at 4.00 per cell.

RE: What is the cutoff point for lipo's
 

The low voltage "resting point" for lipos is 3.5-3.7 volts per cell. For power systems there's no useable capacity below 3.5 volts , but since you are using in radio app with low current then there will be some useable capacity below 3.5 volts/cell. I'm not saying that you should use this extra capacity.

RE: What is the cutoff point for lipo's
 

I don't charge mine all the way either. My dx7 has done some funky stuff with a full lipo charge. I usually charge to 12- 12.1 v. I recharge at 11.4v. on the screen.

RE: What is the cutoff point for lipo's
 

Actually once the voltage drops below 3.4v you only have a few minutes left with the TX.



Gorish: JR and Spektrum TX's seem to be tolerant of higher voltages.

I've been using LiPo packs with them w/o problems as have many other members at our field.

However I gave a friend a brand new LiPo pack to use with his Futaba, and it blew the regulation circuitry on the third day of use.

RE: What is the cutoff point for lipo's
 

Been wanting to do this mod to my DX7 for a while now but just havent gotten around to it yet.

http://dimensionengineering.com/appn...ektrum_mod.htm

If your Google skills are up to it...do some more research on the subject. While the above link will describe how to change out the voltage regulator, it doesnt cover how to reprogram the low voltage warning.

When you go to a 3cell lipo...the voltage is about .6 volts higher when fully charged compared to the stock NiMh battery. I have read it before but dont remember where...that you can reprogram the DX7 to warn at the correct time of low voltage so you wont end up killing your lipo by relying on the current programming telling you that your battery needs charged.

If you dont reprogram this feature set...and rely on the factory configured setting...you will drain the lipo too low and risk possible damage to the battery or your DX7. If you do not reprogram this...you should keep a check on volts per cell and recharge when you get around 3.7 volts per cell or so.

goodluck

PS...after this mod, or when using a lipo even without the mod...keep in mind you wont be able to use the charge jack on the TX any longer. Remove the lipo and charge on appropriate lipo charger.

RE: What is the cutoff point for lipo's
 

ATVAlliance
thanks for the info. I do take the lipo out when I charge it.

RE: What is the cutoff point for lipo's
 

Excellent!

Wonderful link. Thanks for posting it!

RE: What is the cutoff point for lipo's
 

No problem.

Also...to add. This mod can extend the time between charges of the factory NiMh battery packs. Supposedly(and this info is elsewhere) the voltage regulator used in the DX7 is inefficient. The modded one is more efficient and can double or tripple the in-between charge time of even the factory pack. Providing a non lipo option that will not effect the LVW programming and you can still use the charge jack to charge with.

Personally, I think I will go the lipo or life route when Ido this mod to my TX.