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

Sweet Sue II

A 1/16 Fairey Huntsman 31 from the Dave Milbourn set of plans

All Topics | Latest Posts

Search for:  in Thread Title in  
Ray Wood 221/04/2020 09:59:05
avatar
1849 forum posts
665 photos

Hi Mattias,

Don't worry about Lipo batteries, although if you read the instruction !!! I can't see how your battery pack could be charged any other way with balanced charging plug supplied.

We know examples of fire's thanks to social media, YouTube etc, but you also find people who burnt down the house with a barbecue in the Garden !

If they were that dangerous they wouldn't be sold commercially in my view, relax & build the boat 😀

Regards Rayimg_20191228_205028.jpg

Bob Abell21/04/2020 10:20:38
avatar
8734 forum posts
2722 photos

I am very impressed with the way that batteries have developed over the past twenty years

What will they be like in five year`s time?

Day`s to come?

Bob

Ray Wood 221/04/2020 10:26:01
avatar
1849 forum posts
665 photos

Hi Bob,

Yes great for our modelling, but slightly less practical for cars at the moment ! My mate is an RAC man and is spending an increasing time recovering cars that ran out of battery, but is it a breakdown as such ??

Regards Ray (diesel powered)

Banjoman21/04/2020 10:29:03
avatar
1142 forum posts
2414 photos

Hi Ray,

Oh, I think I will continue to worry slightly and build that boat

And indeed things such as barbecues and fire places (both of which we have here at home) can cause fires (and probably do much more often than LiPo:s). Back in the 1980s, an aunt of mine made a very serious error: she'd enjoyed a cosy wood fire of an evening, and then, being (too) tidy, removed the (as she thought) burnt-out ashes before going to bed. The ashes she put in a plastic (!) bucket, which she then pushed under a chair in the entrance hall, intending to take it out to empty next morning. However, she woke up in the middle of the night (actually, the cat woke her up!), with flames coming up the stairs from the hall to the second floor, where she slept! She had to climb out through a window, and was lucky to survive! If it hadn't been for the cat, who knows how it might have ended?! The fire brigade managed to save the house, although it needed extensive repairs.

From which I learned (a) never to clean out the grate (or the barbecue, for that matter) on the same night as it was used, and (b) to use a proper, made-to-purpose steel ash can with a heavy lid and a bottom raised to two inches above the floor for storing (even cold) ashes until final disposal (on the compost heap, usually).

As for the balancing dervishes and all that, my charger does have a mode (called Charge) expressly for the purpose of charging LiPo:s without a balancing lead. But I'm not going to use that mode, am I now?!

Thanks again, though, for your encouraging words and kind help

Mattias

Edited By Banjoman on 21/04/2020 10:37:02

Edited By Banjoman on 21/04/2020 10:38:09

Ray Wood 221/04/2020 11:17:24
avatar
1849 forum posts
665 photos

Hi Mattias,

I don't know very much about electrics but should your battery be rated 30C for fast discharge ??I

I bought one some time ago thinking was ok but the boat was very slow but for a long time !!

I'm sure DM will let us know in due course 😀

Regards Ray

Ray Wood 221/04/2020 11:20:03
avatar
1849 forum posts
665 photos

Hi Mattias

Forget my last, I see it's 35C 😯 senior moment !!

Regards Ray

Banjoman21/04/2020 11:27:53
avatar
1142 forum posts
2414 photos

Hello Ray,

Yup, 'tis 35C – and as it happens the exact same brand and spec as the packs that Dave M. put into his two prototype boats a few years ago. So, there's precedent

Mattias

Dave Milbourn21/04/2020 13:17:33
avatar
3968 forum posts
258 photos

Ray

Not necessarily for your benefit but you've raised a point about the terminology applying to batteries.

The C rate indicates the theoretical current which could be sustained while discharging the pack over a period of one hour until it was exhausted, so the C rate for a 2600mAH pack is 2.6A. The 35C discharge rating gives a value for the maximum current discharge rate that the pack will deliver. So Mattias' 35C pack can discharge at a rate up to 35 times the C rate, which is 35 x 2.6A or 91 Amps. That could be maintained, however, for just one thirty-fifth of an hour.

Dave M

Ray Wood 221/04/2020 14:59:49
avatar
1849 forum posts
665 photos

Thanks Dave,

Like most things in life I learned that the hard way 😀 bought what to me looked like all my other batteries of course it wasn't !!

Still none of us are exercising our batteries of any sort at he moment !! SWMBO suggested I dig a hole in the Garden & hope for rain 😯,

Regards Ray

Banjoman22/04/2020 07:23:20
avatar
1142 forum posts
2414 photos

Well!

Yesterday afternoon, the postman turned up with a nice, big package, that had taken a full week (!) to travel the +/- 14 miles (!!) from Albatros Modelbouw in Mechelen – but then I read in the paper yesterday that what with lockdowngenerated on-line ordering, the Post Office has to handle the same volumes now, week in, week out, as it usually only does in the run-up to Christmas (which might incidentally also explain why I've not yet recieved my copy of the May issue of MB).

In any case, there it was, and first out of the box was this beauty: a Robbe RO-Safety dedicated LiPo charging and storage box:

verktyg497.jpg

According to the specs it is good for simultaneus storage of up to the equivalent of two 6S 5,000 mAh packs, so my little 3S:er had plenty of elbowroom, all to itself.

verktyg498.jpg

For the details on the features and specs, see **LINK**. Obviously there's only one way to really know if it does what it says on the box (ha!), and I most sincerely hope I'll never find out, but in any case it is a pretty nice piece of kit. Rather more pricey than the usual soft LiPo bags, but I'm happy enough to have spent that on peace of mind.

Furthermore, there was a couple of packs of Z-Poxy finishing resin (and no, I don't expect to use all that on this build; I'm just stocking up, is all) ...

verktyg499.jpg

... and glassfiber cloth in 25 and 100 gram/m2 weight respectively.

verktyg503.jpg

I also recieved a receiver ...

verktyg500.jpg

... and a Hitec HS-81 servo.

verktyg501.jpg

After my days work was done (I'm still working full time from home), 'twas time to set uip out on the back terrace, and fully charge the LiPo, which went completely hassle free, I'äm delighted to say ...

verktyg504.jpg

... and then to bind the receiver, solder on a Deans plug on the powefr leads of the esc, connect it to the LiPo and set it up with the programming card (another doddle -- that card was well worth he money!) and finally test the motor-and-esc set-up.

Everything went swimmingly well: the motor runs nice and smooth, forwards and backwards, and is very quiet, too.

fhbygg9.jpg

All in all a very successful afternoon, which I then rounded off again, back out on the terrace, by running the storage mode (dis)charging programme on the LiPo, to take it back down to 3.8V per cell. As I won't be using it very much during next stages of the build, I figure it'll be better that way; it can still be used for any occasional testing needed, and then topped up every now and then back to said 3.8V/cell storage voltage.

verktyg505.jpg

A couple of things rather struck me during the charging and discharging process.

Firstly, the LiPo didn't increase its temperature in any way that could be detected by simple touch, which of course was reassuring.

Secondly, with the press of a few buttons, the charger very neatly displayed a lot of measurements, including current voltage per cell, which meant that progress was easy to follow, which in turn also felt very reassuring.

All in all, I rather think I've been getting me boxers in a little more of a twist over this whole LiPo thingummy than what was really necessary – but then again, I feel much happier with having been perhaps overly cautious than the opposite.

To be continued ...

Mattias

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Boats? Use our magazine locator link to find your nearest stockist!

Find Model Boats!

Support Our Partners
Premier March
Sarik
Nylet
Premier Thursday
Tony Green Steam
Shrek
Cadma new
Pendle Boilers
Shopping Partners
Social Media

'Like' us on Facebook

Follow us on Twitter

Pin us on Pinterest

Member Contributions
Distributors of Model Boats for our overseas readers
Highlights

Make sure you never miss out on the latest news, product reviews and competitions with our free RSS feed

Make your own contribution to the Website

We welcome well written contributions from Website members on almost any aspect of Model Boating with a particular emphasis on practical hints, tips, experience and builds.

In order to maintain a consistent standard and format, all suggestions should first be sent to me by Personal Message for approval in principle. Only a very limited amount of time is available for editing contributions into a suitable format for placing on the website so it is important that the material is well presented, lucid and free from obvious spelling errors. I think it goes without saying that contributions should be illustrated by appropriate photos. I shall be happy to give advice on this.

The Member Contribution area offers space for short informative mini articles which would not normally find a place in Model Boats magazine. It is an opportunity for Website Members to freely share their  expertise and experience but I am afraid that virtue is its own reward as there is no budget to offer more material recompense!

I look forward to receiving your suggestions.

Colin Bishop - Website Editor