OLD LIPOS

[Eric Robson]

I threw a 4s lipo in a tub of water in the garden after cutting the leads off in February nothing happened, a few weeks later I put it on a stone slab in the garden. After reading this thread I went to check it, 2 cells had 70%left in reading 3.9v. Its been out in all weather's including snow and below 5 degrees. I should rescue the 2 good cells, seems they are indestructible. 

[Stuart Z]

Eric 

 

Was this salt water?

[Eric Robson]

No it was rain water.

[Stuart Z]

Eric

 

It’s the salt that makes the current flow. 
 

[leccyflyer]

It's also the salt in solution which permits the electrolytic corrosion of the battery terminal tabs, potentially leaving the lipo not fully discharged, but with the connections through which the individual cell voltage could be monitored essentially all but gone, which is a far from ideal situation. This method of discharging lipos has been completely discredited and should not be followed..

[GrumpyGnome]

We need an emoji for banging ones head against a brick wall.....

[Bruce Collinson]

2 hours ago, GrumpyGnome said:

We need an emoji for banging ones head against a brick wall.....

That’s the off switch surely?

[Frank Day]

Bucket of salt water in the garden for a few days, should kill them completely, water goes greeny colour.  More fun, put in  a  fire pit or non flammable area and stab with a sharp thing on a long stick(not recommended)

[leccyflyer]

The water is probably going a greeny colour because the terminal tabs are being dissolved by electrolytic corrosion, which makes it quite likely that they are not dead at all, but because the tabs have gone and the connections to the power and balance leads have gone, it can be almost impossible to check the state of charge. 

[Fly Boy 3]

Leccy flier. What connectors do you use on your Lipos please ?

[Fly Boy 3]

How ieasy to solder leads to bulb connections may I ask ?  Cheers

[Martin Harris - Moderator]

Very.

 

Tin the wires and a spot on the casing, hold the wires onto the terminal and tinned spot and apply the soldering iron.

[J D 8]

All one needs is a lead with your favored lipo connector one end and crimp on spade connectors the other end to fit headlamp bulb. Ask at a garage for some old ones as it is usual for only dip or main element to be gone and the other still work.

[leccyflyer]

Very easy to solder a short piece of silicon coated wire, with a 4mm gold bullet connector onto the body and end terminal of a bulb. It's just a matter of abrading the surface of the bulb body with a fine file, or a Dremel, to make sure it's completely clean, then tin the surface contact point, tin the wire end and make the joint. Couple of pictures to illustrate - I've taken the wrap of insulating tape off one so that you can see the contact points.

 

 

 

[Martin Harris - Moderator]

JD8's method is easier for a lamp (bulbs are what you plant in the garden, as our storemen at work drummed into me!) with spade connectors - you could solder to them or use a dedicated 3 wire headlight connector from a scrapyard (or Halfords!)

 

Remember that if you use a halogen headlight lamp, it needs to be kept scrupulously clean (use meths or alcohol) and not handled by the glass or it will fail quickly.  It will also get VERY hot.

[leccyflyer]

27 minutes ago, Fly Boy 3 said:

Leccy flier. What connectors do you use on your Lipos please ?

For the majority of my lipos, from 2s1p 1000mah small ones up to 5s1p 5200mah larger ones I've standardised on 4mm gold bullet connectors, male pin on the nattery positive, female socket on the battery negative, to give a polarised set, with the red lead cut slightly shorter, by a connector length, so that no part of the two connectos can easily touch. Heat shrink tubing used to only leave the contact area of the male pin exposed, then sexured with a wrap of insulating tape to remove any possibility of connecting the battery to itself. The male pin is then shrouded with a length of blue Sullivan snake outer, which fits perfectly and encases the entire metal surface. These are coded green for charged, blue for discharged, to keep track of the packs in use.

 

For my smallest packs I've standardised on the wee red JST plugs and sockets. My larger packs, 6s1p 4000-5200mah now have 5.5mm gold bullet connectors, using the same protocol as for the 4mm ones.

[leccyflyer]

6 minutes ago, Martin Harris - Moderator said:

JD8's method is easier for a lamp (bulbs are what you plant in the garden, as our storemen at work drummed into me!) with spade connectors - you could solder to them or use a dedicated 3 wire headlight connector from a scrapyard (or Halfords!)

 

Remember that if you use a halogen headlight lamp, it needs to be kept scrupulously clean (use meths or alcohol) or it will fail quickly.  It will also get VERY hot.

I prefer to use bulbs - they are more than adequate to discharge a 3 to 4 cell lipo, they don't need to be kept scrupulously clean, they don't get extremely hot, are essentially no maintenance devices and are just stuck in the drawer between times when they are used. The lipo being discharged is done outdoors, underneath a Belfast sink planter, in any sort of weather, shining away through the night - the wee voles might get a warm from them on a cold night. That's where the spent lipos sit until they have their leads clipped and go back under there to await transit to the tip.

[Martin Harris - Moderator]

+1 for something like an 18 or 21W lamp - indicator or brake light filament from a failed rear/brake light one.

[Fly Boy 3]

Thanks for interesting information. I useDeans connectors, that’s the reason for former question. Thank you.

[leccyflyer]

For a Deans connector it would be a simple matter to just make us a pair of short fly leads and solder those directly to the bulb body, as shown.

[John Lee]

 

Very much like Leccy's, I just choose the appropriate connector for the battery.

[leccyflyer]

Very neat that John, ideal if you use a number of different connector types.

[Don Fry]

Caviate, I live in France. Am I missing something.. 

Down my local recycling centre is a steel bin for batteries. Any battery. I  asked the bloke, if it was Ok to dump a 5s 4000 in there. It was discharged, wires shorted together. He is God.

 

“of course” he says, “ but why the trouble to discharge it, we assume they carry charge, that’s why the bin is fireproof.

 

Edited April 10 by Don Fry

[Fly Boy 3]

Thanks lads for the info, nice illustration John, got it.

[Shaun Walsh]

38 minutes ago, John Lee said:

 

Very much like Leccy's, I just choose the appropriate connector for the battery.

An HB3 headlight bulb will connect directly to an xt60 connector, just have to trim the plastic on the bulb and bend the bulb connections slightly.