By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by CML

LiPo replacement for Spektrum Tx Li-Ion - care and maintenance?

All Topics | Latest Posts

Search for:  in Thread Title in  
Keith Miles 231/07/2020 23:12:52
464 forum posts
6 photos
(Posted by Steve J on 31/07/2020 22:09:25:

Posted by Keith Miles 2 on 31/07/2020 18:04:00:

... at one time a 500mah NiCd pack was common in a 4-servo set up in an average sized model ... My Rx packs were never less than 4.8v before recharging.

1.2V/cell off load is a long way down a AA NiCd discharge curve.

... As for higher capacity cells, it is also my understanding that there is a greater voltage drop at a given current the higher the capacity of NiMh/NiCd cells of a given physical size e.g. AA 2000mah versus AA 1000mah...

I suggest checking the datasheets.

If your seven servo (flaps or retracts?) model with the 1000mAh battery stops responding and goes in, please don't blame the radio.

Sorry to correct you, but 4.8 volts (4 x AA) is/was the normal operating voltage of receivers and 9.6 volts(8 x AA) for the transmitter. Maximum cell voltage is/was 1.25 volts at full charge, albeit relatively briefly.

High capacity AA, has higher internal resistance due to thinner electrolyte and is therefore more prone to volt drop at a given level of current.

Battery capacity is also NOT a determining factor, as you and a few others seem to believe, in delivering sufficient power to a load. It only determines how long it does it for just as 50 miles worth of petrol won't affect vehicle performance but will only take you 50 miles or even less at full throttle!

And in 40 years of experience, I have never crashed a model due to a flat battery, a battery of insufficient capacity or a failure to charge it nor, for that matter, have I ever run out of fuel in any vehicle I've owned!

Furthermore, you seem to have completely ignored my more recent "real world" figures obtained when recharging after use, something that was done for a reason and something that was impossible to do in the old days when we used to fully charge Tx and Rx packs routinely for 12-15 hours on the most basic of chargers before use. This procedure, however, is what led to the NiCd "memory effect" issue being brought to light due to constant "topping up" of NiCd cells and prompted the introduction of "recyclers" in an attempt to reduce the risk of ever reducing battery capacity. I never had this experience with model flying but have certainly experienced it with power tools. NiMh eventually removed the problem.

 

Edited By Keith Miles 2 on 31/07/2020 23:26:33

Keith Miles 201/08/2020 00:19:23
464 forum posts
6 photos
Posted by Steve J on 31/07/2020 22:03:33:
Posted by Keith Miles 2 on 31/07/2020 21:47:07:

I will, however, from the Spektrum DX9 manual, quote the recommended (but adjustable) cut-off level of 6.4 v for a 2S Li-Po/Li-Ion battery i.e. 3.2 v per cell.

I understand that the manual is wrong and the protection circuit in the battery pack will shut off above this voltage.

Not necessarily wrong if it is there to cover all such cell types and not just the “fancy” supplied one.

I would, however, agree that if the originally supplied battery cuts out above that level, that would not be exactly useful if not potentially dangerous.

That said, and this subject has been previously debated elsewhere, I was, from the outset, nervous about allowing a battery cell of this type to drop below 3.6 volts and so reset the adjustable value accordingly. As it happens, the audible “low battery” warning went off yesterday at an indicated 7.3 volts. I have just finished the recharge of my non-Spektrum, non-internal circuitry battery and it took a tad over 3000mah which tends to support the generally recommended maximum Li-Po discharge of 75%, comfortably prior to the voltage falling off a cliff!

Edited By Keith Miles 2 on 01/08/2020 00:28:00

Richard Clark 201/08/2020 03:40:52
426 forum posts
Posted by Keith Miles 2 on 31/07/2020 21:47:07:

UPDATE (for those who might be interested!).

Just been doing some further research and firstly, "Battery University" states, in concert with Richard's comment:

"As far as the user is concerned, lithium-polymer is essentially the same as lithium-ion".

BUT, for me, there seemed to be two key phrases there, so did some further checking in order to confirm my suspicions and to justify my doubts.

My I-Charger 208B, in the base settings menu, has separate provisions for Li-Po, Li-Ion and Li-Fe and the manual for it also quotes significantly different parameters for each cell type in terms of nominal voltage, maximum charge voltage, storage voltage, allowable fast charge and minimum discharge voltage cut-off level.

I won't waste time and space by quoting all of them here but, if interested, you will find the manual online and the aforementioned differing battery parameters are listed on Page 6.

I will, however, from the Spektrum DX9 manual, quote the recommended (but adjustable) cut-off level of 6.4 v for a 2S Li-Po/Li-Ion battery i.e. 3.2 v per cell.

Interestingly, but understandably, this common value for both is higher than that quoted in the I-charger manual by 0.2v and 0.7v respectively.

So, with due respect to present company, I can only again conclude that Lithium cells are NOT all the same and that a level of caution is required in terms of perhaps understandably accepting such statements or in making assumptions.

As for the original subject of this thread, a positive outcome is that I am now somewhat less concerned about storage charging of any LI-Po batteries, especially ones that are only used for very light duty in a transmitter or relatively light duty in only powering a receiver and servos!

It seems to me that storage charging is more a matter of getting the maximum life out of the batteries as opposed to a safety issue, something which seems to be pervasive where Li-Po cells are concerned and perhaps, therefore, open to misunderstanding (I include myself!) of what is important and what isn't!

As for a need to balance charge, as opposed to a recommendation..............?

A subject for another thread, perhaps?

smiley

 

 

Edited By Keith Miles 2 on 31/07/2020 21:53:57

Keith,

The 'Battery University' is of course merely some probably single-handed self-appointed 'expert'. with delusions of grandeur. No more than that

I agree with half it's comment and disagree with the other half.

Yes, Lithium polymer batteries ARE essentially the same as all the others. Batteries are normally defined by the chemistry and ALL batteries work on the transport of 'ions'.

But for some unknown (to me) 'reason' lithium-based batteries have diverged from that totally logical convention of naming batteries by battery chemistry 'They' hav decided to lump all but one of the lithium-based batteries together under the meaningless name of 'Ion', which tells you nothing, and name one containing cobalt by the case!

It's a complete nonsense

But I disagree  with  othrr half of hr 'University' comment .  Of course the battery chenistries  are important to the end user as thr ed voltragr varies by batterey chenistry and is.critical.

You re right about 1000 ma being safe. I had forgotten that we were all happy with 500 ma ansd very little has changed since.

Edited By Richard Clark 2 on 01/08/2020 04:11:50

Keith Miles 201/08/2020 09:31:17
464 forum posts
6 photos
Posted by Richard Clark 2 on 01/08/2020 03:40:52

“The 'Battery University' is of course merely some probably single-handed self-appointed 'expert'. with delusions of grandeur. No more than that

I presume that you have checked the Battery University website? If not, I suggest that you take a look as it is pretty comprehensive and also associated with Cadex Electronics, a company that is headed up by someone who appears to have achieved “grandeur” some time ago and who appears to be rather more than a “self appointed expert”.

“Yes, Lithium polymer batteries ARE essentially the same as all the others. Batteries are normally defined by the chemistry and ALL batteries work on the transport of 'ions'”

I would maintain that “essentially the same” , given the differing stated parameters of lithium based batteries, is a phrase open to misinterpretation and hardly helpful in avoiding confusion and potential misuse.

“But I disagree with othrr half of hr 'University' comment . Of course the battery chenistries are important to the end user as thr ed voltragr varies by batterey chenistry and is.critical”

Exactly! See previous comment.

You re right about 1000 ma being safe. I had forgotten that we were all happy with 500 ma ansd very little has changed since.

Thanks for that!

Maybe at least one contributor to this thread is considerably younger than you or I or has simply forgotten about how things were in the old days? I recall another relatively recent similar debate elsewhere on this forum about electric flight and the simple need to choose the appropriate equipment for the task in hand.

I would also correct what I said earlier about my “real world” battery usage figures for my “four servo” models. I should have said five servos and was forgetting that it is now the convention to use two for ailerons not one!

I think we would also both agree that additional servos for flaps and/or retracts are of little significance in terms of determining battery capacity given that they are only used briefly, unlike aileron and elevator and to a lesser extent, throttle and rudder.

Nothing wrong with “overkill” on battery capacity (or anything else, for that matter) unless, perhaps, it adds unnecessary weight or cost or creates a potential problem which would otherwise not exist.

And there’s also the option of having a spare fully charged battery to hand if you expect to be doing a LOT of flying or need to supply a high current load!

 

Edited By Keith Miles 2 on 01/08/2020 09:46:40

Bob Cotsford01/08/2020 10:01:40
avatar
8744 forum posts
487 photos

Once upon a time I ran models with glow and petrol motors, most of which were fitted with 2S LiFe packs to power the electronics. What I found was that for most medium size (90-120 4 stroke) models after 4 or so flights I was putting 150-200 mAh charge back in, and that was with a few digital servos in use, but no 3D antics!

For most club sports models I found 1100mAh packs plenty, the exceptions being where more current hungry servos needed something more robust to maintain voltage levels. For those I found the cheap Zippy LiFe packs needed replacing with metal can A123 packs. Total energy consumption on these models was little more than for models running standard servos, the difference was in the peak current demanded.

Keith Miles 201/08/2020 10:19:21
464 forum posts
6 photos

A sincere apology!

I recently attributed a comment to the wrong contributor when I said, in a response to Richard “Maybe at least one contributor is considerably younger than you or I.....”

It was, in fact, Richard who prompted the comment!

OOOPS!

smiley

Keith Miles 201/08/2020 10:55:37
464 forum posts
6 photos
Posted by Bob Cotsford on 01/08/2020 10:01:40:

Once upon a time I ran models with glow and petrol motors, most of which were fitted with 2S LiFe packs to power the electronics. What I found was that for most medium size (90-120 4 stroke) models after 4 or so flights I was putting 150-200 mAh charge back in, and that was with a few digital servos in use, but no 3D antics!

For most club sports models I found 1100mAh packs plenty, the exceptions being where more current hungry servos needed something more robust to maintain voltage levels. For those I found the cheap Zippy LiFe packs needed replacing with metal can A123 packs. Total energy consumption on these models was little more than for models running standard servos, the difference was in the peak current demanded.

Useful info there, Bob. I was wondering about digital servos, should I ever decide to buy any! Thus far, I’ve not felt the need to do so for the type of flying that I do.

I can see why different cell chemistry or larger capacity can reduce actual or potential voltage drop issues and in case anyone has misunderstood, my earlier comments about this were entirely related to higher capacity cells of the same chemistry whilst also maintaining the same physical size as in the case of AA, AAA etc.

There does seem to be a fairly common misconception, for example, that a 4-cell 2000mah AA Rx pack will perform equally as well as a 4-cell 1000mah AA Rx pack when, in fact, there is a trade off, although this might not be an issue, in practice, dependant on the load.

Again we seem to have strayed off topic but it’s all good stuff which hopefully, helps to divert our attention away from the negative effects of Covid19!

Richard Clark 201/08/2020 22:18:42
426 forum posts
Posted by Keith Miles 2 on 01/08/2020 10:55:37:
Posted by Bob Cotsford on 01/08/2020 10:01:40:

Once upon a time I ran models with glow and petrol motors, most of which were fitted with 2S LiFe packs to power the electronics. What I found was that for most medium size (90-120 4 stroke) models after 4 or so flights I was putting 150-200 mAh charge back in, and that was with a few digital servos in use, but no 3D antics!

For most club sports models I found 1100mAh packs plenty, the exceptions being where more current hungry servos needed something more robust to maintain voltage levels. For those I found the cheap Zippy LiFe packs needed replacing with metal can A123 packs. Total energy consumption on these models was little more than for models running standard servos, the difference was in the peak current demanded.

Useful info there, Bob. I was wondering about digital servos, should I ever decide to buy any! Thus far, I’ve not felt the need to do so for the type of flying that I do.

I can see why different cell chemistry or larger capacity can reduce actual or potential voltage drop issues and in case anyone has misunderstood, my earlier comments about this were entirely related to higher capacity cells of the same chemistry whilst also maintaining the same physical size as in the case of AA, AAA etc.

There does seem to be a fairly common misconception, for example, that a 4-cell 2000mah AA Rx pack will perform equally as well as a 4-cell 1000mah AA Rx pack when, in fact, there is a trade off, although this might not be an issue, in practice, dependant on the load.

Again we seem to have strayed off topic but it’s all good stuff which hopefully, helps to divert our attention away from the negative effects of Covid19!

The only time I've noticed any difference is on a big heli. I replaced the £12 JR analog servos with £55 Multiplex 'Profi' digital servos and it made a big difference.

Our radios are not truly 'digital' anyway. Because the stick potentiometers (or hall effect sensors) are analog, the pots in the servos are analog, and the transmission is a chain of variable length pulses.

The stuff in between these items may be digital but the overall system isn't. There are several analog to digital or digital to analog conversions going on.

Keith Miles 202/08/2020 13:09:21
464 forum posts
6 photos

Thanks to all for your contributions, including the usual thread drift!

One item of interest was Pete Christy’s comment about the 2.4 GHz current demand compared to 35 MHz (and perhaps 27 MHz?). I didn’t know that.

I will assume, however, that this was referring to power consumed to perform the function of producing the radio signal because it immediately seemed to me, on moving to 2.4 GHz, that modern sets did, and do, seem far more power hungry. This, however, is presumably due to the additional features and computerisation!

As for my DX9, I can certainly see why a non-Spektrum, externally chargeable Lithium type battery is a preferred conversion as the Spektrum ones with the latter’s single lead, 2-pin PCB plug and internal balancing electronics are clearly optimised for onboard (and relatively slow) charging at 0.5A, Spektrum batteries ain’t cheap, either, compared to at least one less “dedicated” and more flexible, option of double the capacity, available from 4-Max!

And I would suspect that few RC hobbyists these days have no use for a modern multi-charger, if only a low priced one!

”Dedicated” batteries seem to be, all too often, one of the downsides of much modern technology and sometimes prematurely rendering otherwise functional equipment obsolete! Grrrr!

Edited By Keith Miles 2 on 02/08/2020 13:10:26

Richard Clark 202/08/2020 13:42:11
426 forum posts
Posted by Keith Miles 2 on 02/08/2020 13:09:21:

Thanks to all for your contributions, including the usual thread drift!

One item of interest was Pete Christy’s comment about the 2.4 GHz current demand compared to 35 MHz (and perhaps 27 MHz?). I didn’t know that.

I will assume, however, that this was referring to power consumed to perform the function of producing the radio signal because it immediately seemed to me, on moving to 2.4 GHz, that modern sets did, and do, seem far more power hungry. This, however, is presumably due to the additional features and computerisation!

As for my DX9, I can certainly see why a non-Spektrum, externally chargeable Lithium type battery is a preferred conversion as the Spektrum ones with the latter’s single lead, 2-pin PCB plug and internal balancing electronics are clearly optimised for onboard (and relatively slow) charging at 0.5A, Spektrum batteries ain’t cheap, either, compared to at least one less “dedicated” and more flexible, option of double the capacity, available from 4-Max!

And I would suspect that few RC hobbyists these days have no use for a modern multi-charger, if only a low priced one!

”Dedicated” batteries seem to be, all too often, one of the downsides of much modern technology and sometimes prematurely rendering otherwise functional equipment obsolete! Grrrr!

Edited By Keith Miles 2 on 02/08/2020 13:10:26

The Spektrum batteries (and Futaba ones too) are grotesquely overpriced.

EG: RS Components (once called Radiospares) is very old established and is the largest electronic component supplier in the UK. It is the automatic 'go to' place for much of the UK electronics industry, including foreign owned UK divisions such as IBM, but deals with the public as well.

The most common Lithium rechargeable battery is the '18650' 2.6 Ah and is used by everyone from Bosch garden tools to Tesla cars. The Ah capacity varies somewhat from make to make.  I don't know who makes the RS supplied ones.

£6.92 plus VAT each from RS. If they are the right physical size you would need two. You could take the original battery casing case apart and install these keeping any original Spektrum; protection/charging circuit.

Edited By Richard Clark 2 on 02/08/2020 13:51:08

Keith Miles 202/08/2020 14:20:20
464 forum posts
6 photos
Posted by Richard Clark 2 on 02/08/2020 13:42:11

The Spektrum batteries (and Futaba ones too) are grotesquely overpriced.

EG: RS Components (once called Radiospares) is very old established and is the largest electronic component supplier in the UK. It is the automatic 'go to' place for much of the UK electronics industry, included foreign owned UK divisions such as IBM, but deals with the public as well.

The most common Lithium rechargeable battery is thr '18650' 2.6 Ah and iis used by everyone from Bosch garden tools to Tesla cars.

£6.92 plus VAT each from RS. If they are the right physical size you would need two. You could take the original battery casing case apart and install these keeping any original Spektrum s; protection/charging circuit.

Edited By Richard Clark 2 on 02/08/2020 13:43:18

All “original equipment” tends to be overpriced!

Yes, I am very aware of RS. My former employers had an account with them and I have occasionally used them myself for less widely available components. They, too can very expensive compared to other suppliers but they have always offered massive stocks and good service. In fact, they now have a very large warehouse about five minutes from my house!

As for your suggestion, too much “faff” for my tastes when one can buy a “drop-in” alternative for not much more money. Also, the idea of keeping the protection/charging circuit suggests continuing with onboard slow charging as opposed to external fast charging which defeats the whole object.

The 4-Max 4000 2S one can be balance charged at 4A, externally, in exactly the same way as other Li-POs.

Any onboard charging of a battery within the DX9 transmitter is limited to 0.5A and is not adjustable. Only the battery type can be selected i.e. Li-Po/Li-Ion OR NiMh.

Keith Miles 202/08/2020 22:25:12
464 forum posts
6 photos

Further to my last post I decided, out of pure curiosity to check out those 18650 cells mentioned and my question is this, in the context of “faff”.

Even if it could be made to fit the transmitter, why would anyone want to go to all the trouble of having to solder two cheap cells together, dismantle an otherwise good and relatively expensive one, merely to use the latter’s internal electronics with the former (more soldering) to create a “home brew” pack that would take even longer to charge in the transmitter than the now destroyed, and previously neat and serviceable original and all to save about 12 quid?

Please accept my sincere apologies if this was a wind-up and it went over my head!

smiley

 

 

Edited By Keith Miles 2 on 02/08/2020 22:26:38

Keith Miles 203/08/2020 04:37:14
464 forum posts
6 photos

ERRATA!

I stated that the maximum charge rate of the Tx internal charging circuit was 0.5A. It is 0.2A, which I knew, but somehow forgot!

Duh!

It did occur to me that it used to take a great deal longer than three or fours to charge the original 2000mah battery!

smiley

leccyflyer03/08/2020 07:27:17
avatar
1570 forum posts
332 photos

I have a DX7 and an Futaba FF9,l both fitted with the aftermarket Hobbyking 3s1p 1500mah LiFe packs which I now charge at 0.8c and takes about an hour an a half. I balance charge in the transmitter, through the non-used lead, with the balancer also connected. It's relatively quick and hassle free, but, even with LiFe I want to be in attendance whilst charging. My DX9, with it's dedicated low current charger is even less hassle - just plug in occasionally , happy to leave it unattended and a few hours later the little charging light on the front goes off and it;s done.

In comparison to the weekly, or even daily, 12 =14 hour overnight charging of yesteryear's 35mhz transmitters it much quicker and the lower current requirements of 2.4ghz makes charging an occasional rather than daily occurrence. For the cost I wouldn'y personally consider making up bespoke packs for transmitter use, neither would I use normal LiPo packs requiring rather more care in use than the less volatile LiFes. The only downside I can see is the described feature where the voltage falls off a cliff with LiFe, reading as fine right up until there isn't enough grunt to carry on flying,. AFAIK I've never got close to that. I did puff one LiFE pack through leaving the TX on, which killed that battery-since then I have also gone to 0.8c charging instead of 1.0C.

Richard Clark 203/08/2020 09:15:13
426 forum posts
Posted by Keith Miles 2 on 03/08/2020 04:37:14:

ERRATA!

I stated that the maximum charge rate of the Tx internal charging circuit was 0.5A. It is 0.2A, which I knew, but somehow forgot!

Duh!

It did occur to me that it used to take a great deal longer than three or fours to charge the original 2000mah battery!

smiley

 

Looking at your post and also bearing in mind leccyflyer's post above, 0.2 Amps is crazy low.

Even the Futaba M6 that I owned in the mid 1970s came with a charger that provided 0.5 Amps for the transmitter and 0.2 Amps for the receiver pack. (Which is sometimes of a lower capacity than the transmitter battery, but  if they are the same capacity you can use the transmitter outlet but if you do  you can't charge the transmitter at 0.5 Amps simultaneously)

My early 1990s JR was the same.

And my modern Multiplex radio doesn't come with a charger but says 'up to 1.5 Amps'. So I use the same 'multi purpose' American 'Thunder Power' charger that charges all commonly available battery chemistries at any charge currents up to 30 Amps and any battery voltages up to 50 volts (14S Lipo for example) you choose to set.

It is 'normal' that the charger sets the charge current. Maybe the Spektrum is  unusual in this respect.

Edited By Richard Clark 2 on 03/08/2020 09:20:48

Steve J03/08/2020 09:49:48
avatar
2051 forum posts
60 photos

Posted by Richard Clark 2 on 03/08/2020 09:15:13:

0.2 Amps is crazy low.

200mA is the slow charge rate for a 2000mAh NiMH.

The MacGregor wall wart charger that I use for my JR PCM9XII and DSX9 (which is effectively a PCM9XII with a Spektrum RF unit) puts out 110mA which is below 0.1C for the NiMHs that these transmitters were supplied with.

My DX9 (2000mAh Li-Ion) goes on charge for a few hours between flying sessions. No problem. I hate to think how many devices with lithium batteries are plugged into chargers in my house at any give time.

Keith Miles 203/08/2020 12:53:48
464 forum posts
6 photos
Posted by Steve J on 03/08/2020 09:49:48:

Posted by Richard Clark 2 on 03/08/2020 09:15:13:

0.2 Amps is crazy low.

200mA is the slow charge rate for a 2000mAh NiMH.

 

True on both counts but slow charging never bothered us in the old days nor was there any debate about differing cell types!

Any internal charger, though, will only be capable of low current because, due to the laws of physics, size matters, as does heat dissipation, in addition to any fire risk considerations!

The DX9, at least, has an internal charger which, according to the manual, is for use with the supplied Spektrum 2000mah Li-Ion and external adaptor and the internal charger is designed to work with a Li-Ion battery that has inbuilt electronics for balancing and cut-off. The manual does not make this clear which probably explains much apparent confusion especially amongst the uninitiated.

Until recently, it seems, only Spektrum offered a battery with the necessary internal electronics for onboard charging in their transmitters so maybe they’ll come up with something else to restore the initial monopoly? That said, unlike some, I have no complaint with Spektrum. It has served me well so far as has their customer service on a couple of occasions.

As for the debate surrounding the merits of varying chemistries I, too, take the view that in-depth comparisons of operational performance is of minimal relevance where transmitters are concerned, given the very low power demand. What turns you on, I suppose (pardon the pun) but I believe in K.I.S.S.

smiley

P.S. I have since noted that some have fitted batteries that have a JST connector which, apparently, has the same pin spacing as the Spektrum PCB plug. Not sure that I would totally trust that myself, though, without further investigation.

Edited By Keith Miles 2 on 03/08/2020 13:18:58

Keith Miles 203/08/2020 16:21:11
464 forum posts
6 photos

I decided to check out that rival “intelligent” battery that I was told about.

Bearing in mind that the “intelligence” would seem to be of little benefit to anyone with a modern “intelligent” multi-charger (the vast majority of us, I would think), and is possibly optimised for use with the relatively very limited capabilities of an internal Tx charging circuit, I note that the “rival” is, seemingly, a Turnigy 2S “intelligent” battery of 4000mah.

So, yes, for a relatively low cost of 17 quid, you actually get more than a rival for the original and twice the capacity BUT with a directly consequential doubling of the time it would take to fully charge it (about 20 hours!) using the Tx and adaptor!

So, again, for me at least, I have yet to see a quicker, simpler or better “upgrade” than the “unintelligent” and immediately more flexible option than that offered by 4-Max which has main power lead with JST connector, balance lead and separate lead with plug for the PCB.

And no, I’m not receiving a “bung”.

smiley

And purely to satisfy my curiousity, I have fired off an e-mail to Spektrum regarding compatibility of, at least, their “intelligent” battery with external chargers as the manual is not clear on this, merely advising in non-specific terms.

leccyflyer03/08/2020 18:40:45
avatar
1570 forum posts
332 photos
Posted by Keith Miles 2 on 03/08/2020 16:21:11:

I decided to check out that rival “intelligent” battery that I was told about.

Bearing in mind that the “intelligence” would seem to be of little benefit to anyone with a modern “intelligent” multi-charger (the vast majority of us, I would think), and is possibly optimised for use with the relatively very limited capabilities of an internal Tx charging circuit, I note that the “rival” is, seemingly, a Turnigy 2S “intelligent” battery of 4000mah.

So, yes, for a relatively low cost of 17 quid, you actually get more than a rival for the original and twice the capacity BUT with a directly consequential doubling of the time it would take to fully charge it (about 20 hours!) using the Tx and adaptor!

So, again, for me at least, I have yet to see a quicker, simpler or better “upgrade” than the “unintelligent” and immediately more flexible option than that offered by 4-Max which has main power lead with JST connector, balance lead and separate lead with plug for the PCB.

And no, I’m not receiving a “bung”.

smiley

And purely to satisfy my curiousity, I have fired off an e-mail to Spektrum regarding compatibility of, at least, their “intelligent” battery with external chargers as the manual is not clear on this, merely advising in non-specific terms.

It;s still a lipo though Keith, so presumably not to be left charging unattended?

The Hobbyking LiFe TX packs have a Futaba lead, A Spektrum lead and a JXT balancing lead so that avoids the undesireable requirement to break and make the main connection to the transmitter whilst charging. IMO it isn;t good practice to regularly disconnect the battery on that transmitter connection to make every charge.

Richard Clark 203/08/2020 19:34:07
426 forum posts
Posted by Steve J on 03/08/2020 09:49:48:

Posted by Richard Clark 2 on 03/08/2020 09:15:13:

0.2 Amps is crazy low.

200mA is the slow charge rate for a 2000mAh NiMH.

The MacGregor wall wart charger that I use for my JR PCM9XII and DSX9 (which is effectively a PCM9XII with a Spektrum RF unit) puts out 110mA which is below 0.1C for the NiMHs that these transmitters were supplied with.

My DX9 (2000mAh Li-Ion) goes on charge for a few hours between flying sessions. No problem. I hate to think how many devices with lithium batteries are plugged into chargers in my house at any give time.

 

Quite.

On the top of our microwave oven there are about 10 'lithium' chargers, not including the model plane ones which are somewhere else. Some are 'wall wart' type, some have a mains cable. They range from a Philips shaver one, through a usb Apple charger to a Bosch 18 cell hedge trimmer charger. All the cables are tangled up and there are only two adjacent mains sockets. If you want to charge any one item it's a right pain. You have to find the appropriate charging cable and then match it to the appropriate mains plug. Pulling the charge plug to see which mains plug moves doesn't work as the  tangle is too tight . Sorting ir all out once a week is hopeless as they get tangled up again far quicker than that

Edited By Richard Clark 2 on 03/08/2020 19:35:49

All Topics | Latest Posts

Please login to post a reply.

Latest Forum Posts
Support Our Partners
Sussex Model Centre
CML
Slec
electricwingman 2017
Sarik
Advertise With Us
Latest "For Sale" Ads
NEW POLL - has the pandemic altered your event safety perceptions?
Q: Has the covid pandemic deterred you from attending shows and events in 2021?

 No, I'll be attending just as many as I usually do
 No, but I'll choose my event with greater care
 Yes, I'll attend fewer events going forward
 Yes, I wont attend any where previously I have

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E!