Who needs enemies ...when you have friends like this

[Paul Luby]

Hi Guys

These are the straps I use to hold my batteries.

Never had a battery slip or work loose.

Paul

[leccyflyer]

The velcro seat-belts that we used to make - before such branded items were available - require nothing more than a few staples and a blob of glue. Now there are commercially available alternatives that make battery retetion, where you can get a strap around them, generally very straightforward.

That said I'm becoming increasingly appreciative of wedges, plates and inserts for hassle-free battery retention, especially with larger batteries.

[Paul Luby]

Hi Guys

Reference the battery plates, wedges, etc, I hope your not talking about charging batteries whilst still in the model.

I used to do that with Nicad and Nimh receiver packs for many many years until an Overlander Nimh receiver pack on its 5 charge developed an internal short and turned my Bleriot XIb from this,

To this,

In about 10 minutes flat.

Ok, the Bleriot was in my Model Trailer (picture below) which was in my garage and the receiver pack was having a top up charge ready for the RAF Champs the day after whilst I was doing the washing up in the kitchen. The trailer container section is 7 ft long, 4 foot wide and 39 inch deep (the cat on top of the trailer is a 12 month old Siberian Forest Cat/Kitten, they don't stop growing till their four and a half years old).

The computer battery charger detected the internal short and stopped the charge (it said internal short on the charger screen), but by then the battery fire was well under way. Below is an internal picture of the trailer prior to the fire,

The model next to the Bleriot is an own design, if you remember the old DB Mascot that was 60 inch span, well the model in the picture is a 84 inch span version that had at the time had a 26 cc petrol engine in it and was used as a general hack model and glider tug. DB designed models are the greatest, won't accept any discussion on that. Below is an internal picture of the trailer after the fire,

The trailer saved my garage and everything in it. The silver stuff under the Bleriot nose is the 2lb of lead I had in the nose to get the C of G right. The 26cc petrol engine it had in it was beyond salvage (ok maybe a little overpowered but it did put, put, put around the sky lovely on a summers evening).

So, moral of the story is, not only LIPO's cause fires, any battery can.

I sent Overlander a picture after it happened just for comment, guess what, no reply. I now never buy any products from Overlander as a result.

I now use two type of batteries and two types only, HobbyKing Nano-Tech Lipos, which I've been using since they were released and have never had a single problem with any of them. The second type is Sanyo Eneloops, again a fantastic battery and never had a problem.

My ignition units on my petrol engines are all Eneloop packs. I use the Nano-Techs for motor power on electric models and as receiver packs on large models combined with an own design "powerbox" so I can have 2 batteries, 2 regulators and 2 receivers to provide redundancy. Each receiver has one Aileron, one Elevator, etc all isolated and pretty bulletproof.

All my batteries are mounted on pull out break away frames so if one starts smoking I can reach in and pull it out complete with mounting frame and cause virtually zero model damage (I keep an aircraft hot area glove handy at all times). I'm an aircraft engineer by trade and I like to design round issues I've had so I don't have them again.

In my garage I have an old small pottery kiln that I got off e-bay. The batteries go in it for charging, the chargers are outside the kiln and the charge leads go through an access hole that is sealed with a ceramic sealant. It has a double skin chimney that goes through my garage roof to vent any fumes should a battery fire occur.

Some may say its overkill but I only get caught out once. Sit down one day and work out the value of all the stuff you have in your modelling area / garage. It will scare the crap out of you, it did me. I'm into electronics as well and a have lot of test equipment, tools, controller boards, computer bits and components in there as well.

Anyhow, sorry it was so long, but that was my bad battery lesson.

Paul

[Yoda]

I didn't know there was a convention for fluffy or spikey batteries! Is it written down or is it just one of those things that most people do (fluffy Batteries)? As an i/c man my batteries tend to be tucked away to help c of g but my Jive is secured with a ring of fluffy and spikey velcro that came with the kit. Can you get coloured and fluffy Velcro. I'm a returning newby to rc flying so still 'building' my fleet of a/c. I'm picking up so much useful stuff on these forums, thank you everyone.

BTW Paul, I love the cats. Was going to get a Maine Coone but thought it would be too big to live in my boat. Should have done it. Any way, I have a lovely Burmese cross which I love to bits. Nasty fire. I never leave my batteries charging unattended but do sometimes charge them overnight. Think I might stop doing that now!

Mike

Edited By Yoda on 19/06/2014 14:21:58

[Paul Luby]

Hi Mike

The Maine Coon would have loved the boat life, they love water and where there's water there's rodents to keep them entertained.

But back to batteries, if they've been stored correctly then there's is no reason why they shouldn't still be serviceable.

Nicad's should be long term stored in a discharged state. If that's how they were stored, I'd give them a couple of cycles, look at the results and then go from there. If they have a good discharge time then they could be good to go.

By that I mean if their 600 mAh packs and they give out 600 mA for nearly an hour without going below nominal voltage then you may have a good set on you hands.

Nimhs tend to be slapped on the fast charger nowadays from new and it's not good for them. Nimhs need what is called a Forming Charge. Nicads didn't need this and have a lower self discharge rate than standard Nimhs to boot.

Your old Nicads, if they haven't been abused by a modern fast charger and have been stored discharged could be could be ok.

Its your call, but do a couple of low rate cycles and see what the results are.

Paul

[Yoda]

Thanks Paul.

I had edited out the bit about having 15 yr old NiCads but you must have read it before it hit the thread. They haven't been used in 15 years but as far as I remember they were left as is in the models so may have been partially charged. As for the rest of your comments, as I'm new to rc electronics and elect is a bit of a black art to me I'll research about how to do discharge timings, cycling and doing low rate cycles.

I'm sure I know you from somewhere in a previous life. PM you.

To stay onish topic... do furry receivers count?

Mike

[Old Geezer]

Going back a few entries, are there any bright ideas out there as to how to separate the red "Teutonic" Velcro supplied with Multiplex kits - especially when the battery is already a snug fit and it is impracticable to lift the battery off the underlying foam (Solius, EGPro etc.)?

[Bill_B]

Ah, the mighty 'Teutonic' red Velcro! Like most things German, it's built to last and grips like the proverbial which is why I only use very small amounts of the stuff. As an example, in my Solius I use one complete piece of the supplied 'red' hooky on the fuselage floor and a very small piece of 'fluffy' on the battery. By small I mean 25mm x 8mm. As the battery anyway has a strap around it, the small piece of 'fluffy' is more than adequate to prevent any fore/aft movement. Hope that helps.

[kevin b]

Posted by john stones 1 on 18/06/2014 22:41:04:

He's a handsome lad Bill, I love dogs

You not saying owt about his weeds then Kevin ?

John

Sorry, I didn't realise they were weeds. I thought it was foliage. I have a lot like it in my garden. Very well established. Looks great with 2 foot of snow on it !              

Anyway, back to the velcro. Why is most of it backed with a heat sensitive adhesive ? I think it's probaly costs, but in many cases it is used in areas subject to temperature variations (not just mdels).

 

 

 

Edited By kevin b on 19/06/2014 19:37:02

[leccyflyer]

Posted by Paul Luby on 19/06/2014 13:39:41:

Hi Guys

Reference the battery plates, wedges, etc, I hope your not talking about charging batteries whilst still in the model.

Not sure where such an assumption would come from. By their very nature wedges, plates and inserts imply that they would be removable, along with the batteries. For the avoidance of doubt though, I certainly was not suggesting charging Lipos in the model and would never do so. .

However, like most folks, I wouldn't have a problem in charging permanently installed Nimh or NiCd receiver packs in-situ -certainly I don;t know anyone who flies an IC model who routinely removes their receiver packs for charging.

[Paul Luby]

Hi leccyflyer

I now charge all my batteries, even my Nimh receiver packs, outside the model since the Bleriot fire. I invest too much time in building my models to risk them to a duff £8 receiver pack.

Mike

You reckon you might know me from a previous life? Oh oh, that could be bad.

Regards cats, my new Siberian Forest Cat and my new Maine Coon are gonna be called, what else, Mig and Sabre. Couldn't help myself, it just sort of seemed right.

If you want to see how more evolved cats are compared to dogs, you can get Maine Coon cats with thumbs, see picture below. Look up Polydactyl Maine Coon on the WWW.

Paul

Edited By Paul Luby on 19/06/2014 23:29:22