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[scimitarjohn]

   Sometimes eBay (other auction sites are available) comes up trumps.  Just got another Digifleet AM Tx, I would have thought this was one of the early 'Custom' Txs as the serial number is only 1824.  So now it's time to replace those manky DEACs (fortunately the boards look in good nick) power up and see what I get.

[roycv]

Hi , I have one of those that I bought myself.
I also have some old round Deacs that still hold a charge,  Not much of a charge I admit but who is counting!  Rather odd putting 7 cells in a Tx, but he did a lot of odd things.Roy

[scimitarjohn]

Hi , I have one of those that I bought myself.
I also have some old round Deacs that still hold a charge,  Not much of a charge I admit but who is counting!  Rather odd putting 7 cells in a Tx, but he did a lot of odd things.Roy

 Many thanks Roy but I use Li ion in just about everything nowadays.  When he started using Ni cads 7 cells did make up a neat hexagonal pack
A new Skyfly set I used as a donor had a 12v battery pack!

[roycv]

Hi, SJ you seem to be into the old stuff, like me!  I have found that the AA high capacity cells they sell now are a mm wider in diameter than before and the old 2 ch. sets with set places for the cells will not shut up properly.  I tried some old 700mAh cells that fitted no problem.

I did some experiments with modern 1100mAh AAA cells and eventually found that a pack of 10 cells (12 volts) fits in without any problem.  I had to isolate the positive and negative wires in the transmitter and extend them to have a female servo connection end.  The existing charging point can also be used for them.

The components shop have made me up 3 similar packs (10 off AAA cells) up to now, and they sit in place without cutting away any plastic with a piece of thin foam to stop them rattling.  They then give me over 4 hours run time. 

My favourite transmitter is the HiTec 40Mhtz FM 3 channel with the slide switch near my right thumb.  It suits my running 30 - 40 inch loa yachts where I use a 3rd. ch. to tweek the fore jib.You can't do that with the 2.4 Ghtz sets unless you have a set position proportional switch on the Tx.
I also use old 2 ch. 27Mhtz and have loads of crystals.  I also run 27Mhtz FM multi channel sets and of course 40Mhtz.  I have so many radio sets I have no need to go into 2.4Ghtz.  Also I have a lot of rx's especially the 3-5 ch. 40Mhtz FM ones.  I bought them very cheeply when the market was flooded with them on the advent of 2.4HGhtz.

I have accumulated quite a lot of 40Mhtz AM crystals which I do not use any more.
Somewhat b******d at the moment with eyedrops having had one cataract done and waiting for the next.  This has kept me out of my workshop, but the improvement in my eyesight has been dramatic, opening up other possibilities.
Regards
Roy

[dodgy geezer]

Ah, interested in the cataract surgery. My eyes are also becoming vintage - and I understand that you can go for long sight or short sight lenses. Most go for long, but if you are a modeller short may be better. Which did you pick, and how good are they for modelling?

[roycv]

Hi DG I was given a choice too.  I went for a multi-focal lens.  I can read my car dashboard and glance straight up at motorway signs etc.  I am very impressed.  I expect to have the other one done in a couple of weeks.
I have my long sight restored to no glasses needed for driving and all the reading elements of old glasses are too strong and was advised to buy some cheap interim glasses for reading. (+2.5).
I am hoping for the best with my right eye which was much stronger than the left when that is done.
Best of luck with options
Roy
 

[chas]

I just had my second eye done last Monday, i was back in the workshop yesterday. I hadn't realised how much extra light i was using to see what i was doing.
  Its a fantastic fuss free operation. One thing though, my mate kept putting off going for his op. The result was that he had problems, nothing that cant be sorted, but it will take a while, probably months . I'd encourage anyone who needs it to go asap.
Chas

[HMS Invisible]

No-cost lipo migration for Tx.

 Replacing the 8.4v hex NiCd  in my Fleet Tx with two scavenged vape lipo cells (500mAh/1.85Wh & 156gram lighter) would maintain the same capacity. It's not actually worth me reviving the original pack for re-use. I could see how well it fares on the surge current stage to jump start and to note how many charge-discharge cycles revives original cell capacity. Previous 600/700 mAh welded NiCd Tx packs took two cycles but were not left crusting over for forty years.

  Another handy refinement would be a battery state monitor, probably a beeping one rather than the bargraph.
I recommend a led bargraph as an on-board fault finder for those that think they can get away, problem free,  with using AA 7.2v NiMh packs or old packs straight from long term storage or if they have never given a thought to internal resistance in a NiMh drive battery.
Test post using PostIMG for 300kB lipo jpeg & 278kB attachment for NiCd then bargraph.
 

[scimitarjohn]

   I just use 18650 Li ion batts now, about 6 quid for branded flat tops, the problem with that is that 3.7v multiples make it difficult to achieve some voltages, ie 8.4v.  I suspect the 8.4 volts comes from that multiple of 7 and 1.2v Ni cads giving 8.4v, I also suspect the design voltage of the Tx may well have been 9v. 7 Ni cads fully charged and in good nick will easily give you 9v anyway, so that's all safe.  So the solution, 3 18650 Lions giving around 11v and a LC7809CV 9v voltage regulator chip, incorporating this into a truly vintage set like the Digifleet should be no problem.  As a matter of interest my AM set takes 50-60mA so even on AA dry cells you should get around 20hrs use, the Lions I use should give around 40hrs use! enough to keep most of us in happy boating me thinks.

[HMS Invisible]

  I'm sure you will find from a bench discharge test that 2s lipo, even the 3.6 nominal type, will always exceed the voltage of a good 7s NiMh or NiCd by virtue of its 4.2volt start point and lower internal resistance. The flat portion of the discharge curve means 3.6 x Ah per cell gives a true watthour rating. I'm currently using up 3.6 Ah 13Wh LG cells (3.6x3.6) in ebike batteries.
 I've repaired, tweaked and adapted these discrete component transmitters. I'm certain, even with the cmos oscillator, a Tx designer, forced to use 12.6 volt, would use the better noise rejection of resistor, or resistors, in preference to a transistor & zener regulator of that day. Later FM Txs & Rx's I've seen have so far split their supply using a resistor for the rf section & a regulator for an encoding circuit and only if it is needed. In the case of monolithic encoder chips, like the NE5044 chip in your 40FM Fleet set, most have an inbuilt linear regulator. Without checking, and before the use of processors, I think Futaba and Hitec only used a series drop resistor between the 8s Nixx supply to drop voltage & burn off excess power.
2.4GHz supply
 I have a boost regulator somewhere and I'd experiment with a 1s to whatever voltage is needed if I was about to adapt a 2.4GHz radio. That's surely worth you investigating whether Ebay lists a 1s to 9v booster for the 2.4G project. A pen bank's charge/discharge circuit will give 5v at ~ 0.5Amp.

[scimitarjohn]

  Never done a discharge test on Lipo's but have on Lions and the results were much what you'd expect.  Not sure why I ended up using Lions rather than Lipos, may have been the energy density, the C value is not too much of a concern for the models I have (all scale).  Great idea, many thanks, no idea why I didn't think of it, used DC-DC convertors at work for all kinds but mostly to keep measurement loops up, already have some on order.

[roycv]

Hi can I join the L-ion conversation?  I make relatively small boats and it would be nice to split the standard 7.2 v NiMh battery to fit either side of the keel.
I was thinking of these cells (2 per boat) and have each one in a holder so I took the cells out for individual charging.  Several of the chargers for a single cell have a USB connection. 
I have looked at chargers that will take 4 single cells (AliExpress has one) but  not sure what to do.  Also I have seen cells advertised with very high Amp hour capacity which I do not believe and also a big variation on price.
I use 3300mAh batteries and these work out about right for me.
 
I would be grateful for any advice on the basics.  I believe the Lithium iron cells are the safest as I often leave battries for a while before charging up and using the boat again.
Regards
Roy

[HMS Invisible]

I call them rechargeable lithium cells lipo whether they are vented or not and regardless of the electrolyte recipe.

The boost regulators are electronically noisy & that's why I would avoid 1s Lipo & boost reg in an AM or FM set. The youtube channel "greatscott" has produced a feature on switching regulator noise using a sponsor's EMC testing lab. There's always the SW/MW/LW radio as a poor man's option.

Roy, there are only two points I could add. One is that a high proportion of the forty or so poundland "£2" 2.2Ah pen battery banks that I bought had discharged to below 1 volt between the year of purchase and intended use.
 If it was around 20 that went so low, it was only two (or ~10%) failed to revive if they were okay to begin with. That tallies with results from bigclivedotcom's youtube videos describing them. 1 , 2
  I used 7s3p to augment a 7s4p severely degraded battery in a 2nd hand ebike purchase. It's not flagging after about a hundred cycles when it was meant to be a temporary fix.
 It's a lot of hassle to balance less-than-premium bulk purchased cells before welding. I'm only making ebike batteries at all because you can use 3.6Ah 18650 & 5Ah 21700 cells to get a 40 to 50 mile range out of a shopper or city ebike with their 28 or 40 cell capacity of a small battery case.
  Point number two is buy a pen spot welder ASAP. It'll come with two metres of Nickel plated steel ribbon & you can make a proper battery as soon as the welder charges up.
 Point number three you already know. 10Ah 18650 cells don't exist and it beggars belief why Ebay and Banggood don't get a deserved kicking for being a part to the scam. Go to the small quantity outlet of cellsupply or other ebike focused sellers for data but it looks like you can get small quantities of reputable 18650 and 21700 cells from Ebay
 



Adding a photo of the aforementioned battery.

In factory condition, PhyLion frog battery in 7s4p, 2.2Ah 18650 is 222 Wh for a 25 mile range on eco assist.
At purchase the cells were high resistance, but the same capacity, range was 4 to 10 miles, so a 7s3p was tacked on. The battery case could accommodate fortynine 18650 cells, so 3.6Ah, 13Wh at £2.90 +vat each would make a 637Wh or 70miles on eco. Nobody does that on a citybike with 20" wheels. It's another candidate for re-spoking the motor on a 26" wheel for 24mph assist.

[roycv]

Hi Invisible thanks for the information.  I have identified the spot welder you pitured at £27 or so.  Not sure why the other similar ones are dearer?
How is it powered?  I am confused as to the use of battery welder in the description.   Is it a battery (18650) powered unit or is it to weld 18650 batteries?  Do I need to buy 1 or 2 18650 batteries to power it?

Good idea though as I never thought of doing my own welding, for Nimh I just soldered with a fast hot iron (100 Watts).
Regards
Roy

[HMS Invisible]

Hi Invisible thanks for the information.  I have identified the spot welder you pitured at £27 or so.  Not sure why the other similar ones are dearer?
How is it powered?  I am confused as to the use of battery welder in the description.   Is it a battery (18650) powered unit or is it to weld 18650 batteries?  Do I need to buy 1 or 2 18650 batteries to power it?

Good idea though as I never thought of doing my own welding, for Nimh I just soldered with a fast hot iron (100 Watts).
Regards
Roy

I added a battery photo after you posted!
There is a 1s 10Ah, high current Lipo inside the case. I have not opened it to look at it's battery.
It has a USBc socket and comes with a charging cable but not a usbc rated charger in a 3-prong plug. It also has a USB output to discharge to a storage level so it functions as a battery bank too.
It is a quality product and it is so easy to use. It will spot weld up to 0.2mm Nickel or Ni plate ribbon to cells.

[scimitarjohn]

Hi Invisible thanks for the information.  I have identified the spot welder you pitured at £27 or so.  Not sure why the other similar ones are dearer?
How is it powered?  I am confused as to the use of battery welder in the description.   Is it a battery (18650) powered unit or is it to weld 18650 batteries?  Do I need to buy 1 or 2 18650 batteries to power it?

Good idea though as I never thought of doing my own welding, for Nimh I just soldered with a fast hot iron (100 Watts).
Regards
Roy

  Hi Roy, anyone who can make 18650 Li ion battery with a capacity of 10Ahr can save the universe, the limit as things stand is probably about 3.5 Ahr.  All batteries can be dangerous if misused, I've seen everyday AA batteries explode and spanners being used on car battery terminals instantly turned into an arc welder!  Li ion, and I think Lipos, are best stored with a full charge but never never ever depleted.  There is, maybe surprisingly, a lot of useful information out there on the web.  All I would add is only buy batteries, and this is probably true for any type of battery, from a reputable source, the best I've found for Lions is Nu Battery - https://www.nubattery.co.uk/ where you can find most types.
         All the best  John

[HMS Invisible]

I recommended in a past post to look up the retail quantity outlet of cellsupply.co.uk wholesaler and now notice it is nubattery.

I keep discharged to 3.6v/cell as recommended. It lengthens the life of your phone, electric vehicle or ebike battery.

Samsung Galaxy phones tip
They added a battery management feature where charging stopped at 85%, or 100% if switched off. That maximises life if you start charging as you go to bed.
 A few months ago they updated the feature to where it was a choice of 80% or adaptive.
The earlier 85% setting was a true 85% but the recent 80% state is really around 65%. It is revealed because if you now switch battery management to "Basic protection", or 100% charge i.e. off, the gauge stays indicating 100% for a whole half hour of the same energy hungry use that would show as draining the battery from the 80% to 60% marks.

[roycv]

Thanks to you both for the information.
The welding ribbon for connecting the cells, what should I look for?  The width ribbon I see on my welded batteries (about 4mm) does not seem to be in the various choices there are. 
Does the welder also weld the electrical wire on to the battery?   I have found some you tube videos on using and have several uses in mind.  Any recomendations for wrapping cells in plastic?
I have ordered one, and thanks again.

Roy

[scimitarjohn]

Thanks to you both for the information.
The welding ribbon for connecting the cells, what should I look for?  The width ribbon I see on my welded batteries (about 4mm) does not seem to be in the various choices there are. 
Does the welder also weld the electrical wire on to the battery?   I have found some you tube videos on using and have several uses in mind.  Any recomendations for wrapping cells in plastic?
I have ordered one, and thanks again.

Roy

   When you buy the batteries you should be offered the choice of tagged or untagged, the tagged ones costing a few coppers more.  I've never welded my cells but guess it's the tags you weld together, Invisible will know more about this.  Heat shrink and the clip separators to make up packs is available at  https://www.componentshop.co.uk/ or probably eBay.

[HMS Invisible]

Thanks to you both for the information.
The welding ribbon for connecting the cells, what should I look for?
 

There is Nickel & Nickel plated steel.
Neither is a great conductor & they probably weld very easily because of that.
I checked my order which was 2 metres of 4-parallel 18650 strip to cover one big battery needing 4-wide & two small jobs needing 2-wide. It's most certainly 0.1 plated because that was all I needed for my batteries.
The attached picture is of 2-parallel to show the idea.
The augmented frog case battery in my prior post used up most of the sample strip that came with the welder. The parallel strip goes further.

The width ribbon I see on my welded batteries (about 4mm) does not seem to be in the various choices there are. 
 

It cuts easily with scissors and you will see 8mm isn't double the price of 4mm.

Does the welder also weld the electrical wire on to the battery? 
 

No, it should easily solder to a tab of scrap ribbon.

I have found some you tube videos on using and have several uses in mind.  Any recomendations for wrapping cells in plastic?
 

   Filter out rubbish from youtube the same way you would with gardening tips.
I used thin polyester for escs and rc gadgets which shrunk with a hairdryer where the thick & rubbery double-bonded polyester stuff needs a heat gun. Battery packs are shrouded in the hairdryer stuff. The smaller the item, the thinner the heatshrink. It's the same material as food packaging tube like bottle-neck security sealer.
 Plastic spacers have a low melting point and they aid pack construction. Nickel tape provides rigidity. Kapton, Barley paper or epoxy-glass card provide sturdy insulation.
  As RC batteries don't endure the shaking of ebike batteries they can get away with strips of kapton tape wherever cell tube damage would short out a bank. Kapton tape is high temperature double bonded polyester (Mylar film is single.)
   The closest I've come to make an rc battery is 1s7p so just hot glued, then welded them in parallel For an 8S1P rc battery, I'd skip spacers but use Kapton strips between cells to not rely on the cell shrink tube simply because I don't know what polyester grade that individual cells come already shrunk in and I have never tested the material..
 Several ebike batteries I've seen had no spacers & parallel cell banks hot glued together to keep rigidity for welding. I tried it myself & it works well.

I have ordered one, and thanks again.

Roy

Give it a half charge and practice with surplus batteries the day you get it.
 I think I started at "3" for 0.1 plated and found it ideal.

[JimG]

  Li ion, and I think Lipos, are best stored with a full charge but never never ever depleted.  There is, maybe surprisingly, a lot of useful information out there on the web.
         All the best  John

Li ion, especially Lithium Iron Phosphate (LiFe) cells do seem to be able to be stored full charged but do not try this with LiPo cells. LiPo needs to be discharged to a storage level (generally around 50 to 60 if you are storing them for more than a day or so. A decent LiPo charger will have a setting for storage discharging. Leaving LiPo cels fully charged for over a few days can lead to the cells puffing up (pressure build up inside) and lower capacity when recharged. If there is any appreciable puffing then the pack is best disposed of safely, discherge it completely with the charger then connect a car bulb to fully discharge. Some then cut off the wires and leave to soak in salt water to complete the discharging, Once at this stage I normally cut the cells open underwater and leave to soak for a couple of days, it's then safe to dispose of normally.
Jim

[HMS Invisible]

Adding photos of the back & underneath of the spot welder.

[dodgy geezer]

Hi DG I was given a choice too.  I went for a multi-focal lens.  I can read my car dashboard and glance straight up at motorway signs etc.  I am very impressed.  I expect to have the other one done in a couple of weeks.
I have my long sight restored to no glasses needed for driving and all the reading elements of old glasses are too strong and was advised to buy some cheap interim glasses for reading. (+2.5).
I am hoping for the best with my right eye which was much stronger than the left when that is done.
Best of luck with options
Roy

I hadn't heard of multifocals.  I must do some research - they sound like the ideal answer.

[roycv]

Hi Dodgy I am going in for the right eye to have the lens renewed tomorrow afternoon so cross your fingers.
The lens I mentioned I have just checked up on. 

It is called an Extended Depth of Focus lens. 
They refer to it as a premium lens but there is no extra charge or any charge. 
I went to Chec (Community eye health care) which does the ops for the NHS and refered there by Specsavers.
Regards
Roy

[HMS Invisible]

Boost regulators & Lithium Ion storage voltage

A clear up of my hobby room turned up the 1s/3s to 12volt boost regulator.
It's intended use was powering a 12volt drone camera. RF suppression encapsulation is by way of an aluminium cup & ground plane. These can be bought from Ebay at £2 to £3. An internet search using MT3608 Adjustable Boost Converter 2A Step-Up Voltage Regulator showed an Arduino & electronic experimenter mail order supplier in Thame, Oxon called Kunkune considerably beating Ebay supplier prices for associated components like diodes, resistors, solderless breadboard, sensors etc.

Lithium Ion or Li-ion cells should be stored at indoor temperature & depleted to 3.6volt per cell.
I've bought more than a dozen ebikes to refurb over the last few years. All of the batteries used Li-ion cells. Batteries left fully charged for a year have become useless for high current drain due to a rise in internal resistance.
The replaced cells are still miles better & lighter than equivalent NiMh cells, so I have hundreds of cells that I can weld into packs to donate to local model boaters.
Two sources that recommend the same as I do.
1 slohibike.com
2 wiredbikes.com