Do you remove your lipo from your transmitter every time?.

[Christopher Morris 2]

Do you remove your lipo from your transmitter every time you turn off & put the lipo back to storage. I personally will make up a short lead of about 3" so i don't have to faf around trying to plug into DX6 awkward 2 pin plug.

[Outrunner]

I remove the lipo from my Hirec transmitter for charging, all other times it stays in the transmitter.

Phil.

[Brian Cooper]

No. . The Lipo stays in the transmitter, and it certainly does NOT go into storage.

It stays fully charged and ready to go for whenever I want to go flying. 

Edited By Brian Cooper on 08/01/2020 20:50:04

[Robert Welford]

Why do you use a lipo in a transmitter?

The current requirement of 2.4 Ghz is so low. Application better suited low to discharge Nimh, or Lithium ion.

My transmitters last days on a single charge.

[dan h]

I also keep my lipo in my dx6 fully charged doesnt seem to do any harm that way as said above its always ready to go.

Dan

[Keith Miles 2]

Posted by Robert Welford on 08/01/2020 21:16:42:

Why do you use a lipo in a transmitter?

The current requirement of 2.4 Ghz is so low. Application better suited low to discharge Nimh, or Lithium ion.

My transmitters last days on a single charge.

In my case, purely for the larger capacity, so less frequent charging.

It’s a 4Max for Spektrum. 4000mah. My NiMh AAs were 2100mah.

And my Dx6i (still with NiMhs) seems to have a much lower drain than the subsequently purchased Dx9, hence the lipo conversion!

Edited By Keith Miles 2 on 08/01/2020 23:29:01

[Christopher Morris 2]

Ah! thanks for the feed back, you hear story's on lipo's that can damage circuit boards if left plugged in. I must admit that the 4x1.5 battery that came with a new DX6e lasted about 4 hours & finshed. The 4ah lipo has done about 8 hour & still showing a good 7.6 volts.

[Nigel R]

Posted by Robert Welford on 08/01/2020 21:16:42:

Why do you use a lipo in a transmitter?

The current requirement of 2.4 Ghz is so low. Application better suited low to discharge Nimh, or Lithium ion.

My transmitters last days on a single charge.

I use the battery and charger that came with the TX (Spektrum DX). Its a "Li-Ion" of a long life / low C variety.

It seems to last for a good long while on a single charge.

In a DX6i, I have nimh cells.

[Christopher Morris 2]

The new DX6e only comes with slandered​​​​​​ batteries, & for what ever reason Spektrum deem it very important to charge the public the highest possible price they can for a rechargeable battery pack. at £33.24 for a 2.0 ah. Yet a lipo that fits perfectly is £13 for a 4.0ah. Nearly a third/61% cheaper & twice the output/longevity. Its also fine to fit a lipo as the DX has a lipo setting for this.

[Chris Walby]

My experience is my non lipo TX is frequently on charge and takes forever to get to near 100% where as my lipo Tx will last longer and charge quicker with the lipo it came with.

PS My lipo TX will charge on a wider input voltage range and won't over charge the cells.

[Don Fry]

Word of warning to Spektrum users, the ones fitted with a li-ion batter at factory. Low battery warning is set in factory at 6.4 volts. The transmitter, in my case a DX9 browns out and switches off at 6.6 volts. Reset it above 6.6 volts. Ruined my day, and a very nice plane, when I found that out.

i think the ones that can run on NiMh/alkaline cells are not effected, as they have a lower voltage system to accommodate their batteries.

[Keith Miles 2]

Posted by Christopher Morris 2 on 09/01/2020 09:38:09:

Ah! thanks for the feed back, you hear story's on lipo's that can damage circuit boards if left plugged in. I must admit that the 4x1.5 battery that came with a new DX6e lasted about 4 hours & finshed. The 4ah lipo has done about 8 hour & still showing a good 7.6 volts.

I should have been clearer, mentioning that the DX9, unlike the DX6i is not built for AA cells (4.8-6v) but for Lithium Ion. Came with a lower capacity one than the my current 4Max LiPo replacement. A popular conversion, it seems.

As for damaging circuit boards “if left plugged in”, sounds like another one of those “myths” to me, Either that, or misuse.

The only thing that might damage components is excess voltage not the chemistry that produces it. You do have to be careful about “on board” charging however, with the supplied charger, if you change the battery type! That’s why my 4Max is removed for charging!

Edited By Keith Miles 2 on 09/01/2020 13:54:22

[Keith Miles 2]

Posted by Don Fry on 09/01/2020 13:22:27:

Word of warning to Spektrum users, the ones fitted with a li-ion batter at factory. Low battery warning is set in factory at 6.4 volts. The transmitter, in my case a DX9 browns out and switches off at 6.6 volts. Reset it above 6.6 volts. Ruined my day, and a very nice plane, when I found that out.

i think the ones that can run on NiMh/alkaline cells are not effected, as they have a lower voltage system to accommodate their batteries.

Why let it get that low?

When I see less than 7.4 volts on the main screen, I recharge.

As you may know the discharge rate increases rapidly when it gets below nominal operating voltage.

That “headroom” thing again!

[Don Fry]

Keith, read the post. The system has a warning function, the warning function, surely, is there to tell you you have left it almost too late. Not much point fitting a warning system, which effectively says, "you crashed 10 minutes ago, bozo."

Better a warning system, " Fool, land, now."

Bit like having a fancy car, as it runs out of fuel, and the sultry lady on the computer starts to cackle, "walk back 7 miles to the nearest fuel, hope to remembered your raincoat, it's raining." Common sense?

[Erfolg]

Just a thought, how does charging a Lipo battery in a tx fit with all the warnings we have received about charging Lipos, that they should be removed from models, not left unattended during charging, and should be charged in a area where any fire will not be an issue?

[Christopher Morris 2]

Posted by Erfolg on 09/01/2020 19:42:30:

Just a thought, how does charging a Lipo battery in a tx fit with all the warnings we have received about charging Lipos, that they should be removed from models, not left unattended during charging, and should be charged in a area where any fire will not be an issue?

This is partly why i was asking.

[Don Fry]

Erf, you might be right. But in the world of 2020, how many devices across the world do get this charge regime.

Back up memories, charge on an reasonably inert surface, charge responsibility. See other posts for an ability to do risk assessments.

[Keith Miles 2]

Don,

I take your point and would agree that such a system is really a superfluous gimmick unless set to a realistic level. 3.3 volts is the minimum recommended cut-off level for avoiding damage to lithium cells and not, necessarily, the minimum level recommended to prevent a crash. Indeed when my little helicopters reach the minimum level, an LED flashes and it flashes only a few seconds before the heli drops out of the sky! That is why you use a timer! And remember that thing about voltage drop under load? A Tx uses far less current than a motor which might give you a false sense of security!

Forget the pointless gimmick and keep an eye on that other piece of information, i.e. the voltage reading on the main screen which is most certainly not a useless gimmick!

Just  re-checked the manual for my DX9, pages 2 and 5, and, sure enough, the warnings about battery use are there!

Other postings,

First, let’s not confuse Li-0n and Li-Po. Most on board charged batteries in this context are the former not the latter.

As always, best to follow manufacturers’ advice and instructions (as in the case above!) unless you really know what you are doing and what the likely consequences might be!

Edited By Keith Miles 2 on 09/01/2020 21:17:04

[Don Fry]

Keith, the point of my warning, your last sentence, I did follow the manufacturers advice. I left the transmitter on the manufacturers setting. It was too low. Plane crashed. They messed up. Warnings are not superfluous gimmicks. They warn.

Set the voltage higher.

Plane eventually hits ground for a reason not Spektrum related.

[Keith Miles 2]

Posted by Don Fry on 09/01/2020 21:22:25:

Keith, the point of my warning, your last sentence, I did follow the manufacturers advice. I left the transmitter on the manufacturers setting. It was too low. Plane crashed. They messed up. Warnings are not superfluous gimmicks. They warn.

Set the voltage higher.

Plane eventually hits ground for a reason not Spektrum related.

 

Don,

Firstly, I’m a little confused. You seem to suggest that a crash occurred due to a Spektrum Tx issue then you seem to say the reverse.

Anyway, moving on.

Does your manual not also advise about ensuring that the Tx battery is fully charged before use?

Mine does.

I also thought it was common knowledge that a 2S lithium battery, for example has a working voltage of 7.4 volts, and an initial full charge voltage of just over 8 volts.

Does your Tx, after switching it on, not constantly display the voltage on the main screen either?

Mine does.

So, if the information is missing from your manual AND there is no voltage indication on the main screen, I think you have a very good reason for sending the Tx in for repair, and for also writing a letter of complaint to Spektrum!

 

Edited By Keith Miles 2 on 10/01/2020 00:51:08

[Don Fry]

Keith, thank you for a re-education on the basic use of a meter and a transmitter.

For the rest of the world, who might think it worthwhile, Spektrum transmitters, the ones shipped with  rechargeable batteries, have their low warning voltage set below the voltage where the transmitter shuts down.

If you forget to check, might save a plane.

Edited By Don Fry on 10/01/2020 19:22:39

[Stephen Smith 14]

Posted by Don Fry on 09/01/2020 21:22:25:

Keith, the point of my warning, your last sentence, I did follow the manufacturers advice. I left the transmitter on the manufacturers setting. It was too low. Plane crashed. They messed up. Warnings are not superfluous gimmicks. They warn.

Set the voltage higher.

Plane eventually hits ground for a reason not Spektrum related.

So how is that not Spektrum related? If they sold the transmitter with the battery but the lvc was wrong it's there fault

[Keith Miles 2]

Posted by Don Fry on 10/01/2020 19:22:00:

Keith, thank you for a re-education on the basic use of a meter and a transmitter.

For the rest of the world, who might think it worthwhile, Spektrum transmitters, the ones shipped with rechargeable batteries, have their low warning voltage set below the voltage where the transmitter shuts down.

If you forget to check, might save a plane.

Edited By Don Fry on 10/01/2020 19:22:39

Having giving the matter further thought, I would suggest that perhaps the low volt warning is there to protect the battery from an over- discharge as opposed to protecting a model from falling out of the sky as you infer?

Is it not the case that there is a level at which a lithium cell can be permanently damaged?

The level that the warning is set at would certainly suggest that this might be the case even if, as you say, it might be set incorrectly.

Perhaps the only occasion that the low volt warning might be intended for is where a Tx battery has been left out of use for an extended period and the warning is there to dissuade the user from using it until the battery has been fully charged?

The manual clearly advises that batteries be fully charged before use, in addition to which, as I have already said, the battery voltage is clearly displayed on the main screen and should, for safety, read at least 7.4 volts.

But, of course, to paraphrase what you have said, if you forget to check.....?

Seems to me that no blame can be aimed at Spektrum for doing their utmost to prevent misuse.

RTFM?

If you are still aggrieved, I can only again suggest that you write a letter of complaint to Spektrum.

I suspect that you won’t but, if you do, I would be most interested in their response.

Edited By Keith Miles 2 on 10/01/2020 22:49:43

[Keith Miles 2]

Posted by Stephen Smith 14 on 10/01/2020 21:19:03:

Posted by Don Fry on 09/01/2020 21:22:25:

Keith, the point of my warning, your last sentence, I did follow the manufacturers advice. I left the transmitter on the manufacturers setting. It was too low. Plane crashed. They messed up. Warnings are not superfluous gimmicks. They warn.

Set the voltage higher.

Plane eventually hits ground for a reason not Spektrum related.

So how is that not Spektrum related? If they sold the transmitter with the battery but the lvc was wrong it's there fault

 

There is clearly some confusion here, not helped by typos.

Firstly, I have just re-checked the discharge curve for lithium cells which has confirmed that they have a rapid drop off in voltage just below about 7 volts.

Secondly, in the manual, it states, in a highlighted cautionary warning, that re-adjustment ( though it doesn’t say up or down), and this is the key phrase, “could over-discharge the battery and damage both battery and transmitter”.

This tends to confirm what I have said in my response to Don, i.e. that it’s purpose is precisely that and nothing else.

And note, in particular that it says “damage” and that there is no mention of “brown out” i.e. loss of signal.

The fact that a Tx might “brown out” before the battery hits rock bottom does not surprise me at all and should not surprise anyone else, given some thought.

As long as you keep your eye on the main screen voltage display, the first warning, in essence, and keep your Tx battery fully charged (as advised in the manual) at best or within safe operating limits at worst ( i.e. 7.4 volts for a 2S lithium) you will never have to worry about any low voltage warning feature or, indeed, the absence of one!

Sometimes, it seems, well intended added features can create a misunderstanding of their purpose!

The phrase “headroom” is often used in our hobby in relation to equipment and it means quite the opposite to pushing things up to, or beyond, safe limits, something which, funnily enough, seems to be a feature in other threads!

Fly safe!

Edited By Keith Miles 2 on 11/01/2020 00:32:03

[Don Fry]

Keith, not complicated. Go the system setup, input a higher voltage value for the warning, higher than the brown out (6.6 v) transmitter voltage, lady tells "warning, low battery voltage".

Take heed. Land the plane.

No harm done.