LCT AK74 un and lipo battery?

[emilianoksa]

Thanks to all the encouragement I have received on here over the last couple of months, I have finally been able to order my first rif - an LCT AK sub-carbine said to have excellent externals and reasonable though not exciting internals.

 

Normally the most appropriate battery to power it would be a Nimh 8.4, (nothing bigger would fit) and I was asking the retailer which particular battery and charger was recommended.

 

I was surprised to be told a Lipo 7.4 would be best - it would be a bit easier to fit than an 8.4 and give the gun a better performance. 

 

As a newby I had never even considered a Lipo. I thought guns would need a mosfet and specially strengthened gears to take one, but I was told that there is a lot of misinformation out there about lipos, and that most of the problems with them come from using 11.1 versions on guns that can't take them. I was also recommended a fit and forget Overlander charger at a modest £16 that would require me only to plug it in and not worry about balancing the cells etc.

 

So I began to think about a lipo. However being a worrier and a compulsive checker,  I began to wonder if I would ever leave the house again knowing I had a couple of lipos  at home. I even considered shelling out 50 odd quid which I can't really afford for a BAT SAFE,  and keeping it inside an old ammo box in the garage. 😁 Like I say, I am a terrible worrier.  

 

What would you do? Accept the advice from the retailer and man up, or take the battery in a box everywhere I go, including the pub, 😅  or just stick to my original plan of powering the gun with the less volatile but not very exciting 8.4 nimh?

 

Are companies that provide house and contents insurance prepared to accept lipos on the premises?

[Prisce]

I use 7.4s all the time, not as dangerous as everyone makes out. As long as you use common sense and diligently look after your batteries you will be fine. 

 

I recommend this, get yourself a couple of turnigy 7.4 lipos from hobbyking or somewhere similar. Get yourself an IMAX B6AC, it will charge the batteries, and allow you to constantly monitor the condition of them, and allow you to discharge them when not in use.

 

Then for storage, if you really are a worrier, an old ammo tin, or storage tin, and when your not in, put the batteries in here and put them in the bath tub, keep them away from flammable surfaces.

 

For the batteries, charge them when you want to use them, when you get home, put them back on the IMAX into storage charge.

 

The lipos only go bang when you mistreat them. Treat them with respect and you will be fine.

[Iceni]

7.4v lipos are generally fine without a mosfet. Saying that I have a fet in every gun, and I only have 1 gun that uses an 11.1v all my others are 7.4v 30c block types.

Since it's a V3 gearbox you don't need to open the gearbox to install a fet anyway. You just cut the trigger contacts and resolder them differently. The 2 trigger wires go to the trigger on the fet, the 2 motor wires go to the motor side of the fet, and you make a short section from the fet to the battery. It's the easiest of all the gearboxes to work on if you did want to add a fet at a later date. There's loads of videos on fitting a fet in an AK.

Gears is all bolocks, You don't need specially strengthened anything for 350fps UK guns. If you were to make it into a DMR at 400fps then that is USA standard fps. And as such still wouldn't need anything improving... Anything over that and your not playing in the UK.

Lipo safety is something you need to learn about. They can be dangerous, but so can a mobile phone battery. There is no need to be keeping them in the shed, Keep them in something fire proof if it makes you feel better, But I and most airsofters I associate with just use the plastic containers they come in, and leave them somewhere safe.

The most common things people do wrong with them:

Discharging them too low.
Treating them rough.
Using a crap charger.
Not inspecting them for bulges.
Shorting them.


The low discharge can actually be sorted with a mosfet that has lipo protect. A good example is the Gate NanoHard. It's got a programmable safety for the various voltages of common lipos so once the voltage is at the lower safe level the gun stops shooting, It has it's own fuse, and it's a mosfet. So it solves a lot your worries. It's also pretty easy to fit and not overly expensive £25-30.

Treating them rough is as simple as not dropping them and taking care not to pierce or slash the wrappings.

Get a decent charger there are plenty of threads on this already.

Inspect them at every opportunity. Get used to the size and shape of them. If you notice bulging stop using them and dispose of it.

Shorting them is as simple as making sure they live in the plastic box, and only come out to charge or be used.

 

2 hours ago, emilianoksa said:

Are companies that provide house and contents insurance prepared to accept lipos on the premises? 

Mobile phones, Laptops, Flashlights, E-cigarettes, Powerbanks, Tablets all use Lipo batteries. I wouldn't even tell them.


I recommend Vapex from Component shop. All of my cells are that type.

https://www.componentshop.co.uk/batteries/airsoft/li-po-packs/74v.html

 

[emilianoksa]

Thank you both very much for the information and reassurance.

[emilianoksa]

I'm still pondering this.

 

Will nobody speak up for the humble 8.4 nimh battery?

[Iceni]

Why would they.

NiMh batteries are inferior. They don't have the discharge rate and compact size of lipo.

They have a much steeper discharge voltage drop. So a lipo runs at a higher voltage for longer before falling off.

Nimh weigh more, and don't have the same energy density so are bigger in volume as well.

The only advantage Nimh has is you can throw it at a wall, and stab it a few times.

Lipo is the better system. And it's safe provided you respect them, And your fear of them tells me you are going to respect them.

It's good to have a fear of them, But it should be used for good battery safety, not to avoid them.

[Sitting Duck]

32 minutes ago, emilianoksa said:

I'm still pondering this.

 

Will nobody speak up for the humble 8.4 nimh battery?

 

simply put.....

 

 

Not really - they are bit old school - fine if you like watching ye olde big box TV via SCART

 

At a push, people still might use 9.6v as a stop gap between 7.4v & 11.1v Lipo's

but these days most people upgrade to LiPo not downgrade to Nimah's

7.4v LiPo's come off charge at 8.4v nearly and pack more punch/zest/snap

Often a GOOD 25c 7.4v will nearly match even a 9.6v in rps - honest

 

Any nimah supplied with cheapo china guns will be a bit $hite tbh

and most will not bother to buy a decent new 8.4v - perhaps not even a new 9.6v nimah

 

Especially when some LiPo's from say HobbyKing are so cheap, often cheaper than nimah's from airsoft shops

 

Nimah's croak quicker I reckon, a cell starts to die & next thing you know they are not charging

or very likely when they get old, they lose their charge so damn quickly....

the night before a game they are fully charged....

day of the game, you are changing batteries before you empty one friggin' mag ffs - WTF !!!!!

 

8.4v's have little I can praise about them - unless they work OK and are free

9.6v's - well if you want a bit more punch than a 7.2v or 8.4v nimah - yeah OK but I'm not buying new

 

LiFe's ' 9.9v I'm not impressed with, special settings and stuff and tbh didn't blow me away over a snappy 7.4v LiPo

 

B6 charger - decent cheap LiPo's, nuff said

[emilianoksa]

Well you've convinced me lads, despite my fears. Thanks you for taking the time to do so.

 

Just two more questions, I promise:

 

Would you advise me to have a mosfet fitted or can I eaisly get away without one for a 7.4 lipo? 

 

Do you think the gear box and wiring in the LCT will be strong enough to deal with a 7.4? They are said to be pretty well built but I'm not sure what that means.

[Sitting Duck]

7.4v you will be ok for a while tbh on a new gun - just use it ffs than mess with it

 

if/when you go for a service in 6-12 months THEN perhaps add a mosfet

(v3's can be done without opening up box, but honestly just use it as is for now)

as said a bit down the road if box comes out for tweaks n stuff then add a basic mosfet

 

The box will handle a 7.4v 20c to say 30c burst rating, or in middle 25c

measure space available take off a few mm's and buy best LiPo that fits

 

Honestly 7.4v won't bolt on a turbo NOS mofo 240v national grid bit of badd ass juice in there

(Trigger blew up a gun using a 18v or 24v Drill battery or something for kicks....)

But a 7.4v - almost any gun will cope with that - even AEP's get modded to run on small LiPo's)

 

deans is a worthy consideration to run with over small tamiya if you can solder & happy with gun

best upgrade you can do do most likely or best bang for ya buck.....

 

keep posting until message gets through.....

 

[Iceni]

9 hours ago, emilianoksa said:

Would you advise me to have a mosfet fitted or can I eaisly get away without one for a 7.4 lipo?

You can get away without one. The worst a 7.4 will do is blacken the contacts a little, It's nothing to worry about. The only reason you might want a fet is for the lipo protect. When a lipo discharges you firstly get a steep drop in voltage for the first few shots, then it levels out and stays level for most of the discharge, Then at the very end it will start to noticeable drop off again, the gun will shoot less rounds per second, and the trigger response will be slower. This is when you change them, NOT when the gun can no longer shoot!

Getting 2 decent capacity batteries and swapping at lunch is as good a failsafe as any.

 

 

9 hours ago, emilianoksa said:

Do you think the gear box and wiring in the LCT will be strong enough to deal with a 7.4

 Yes, without a problem. LCT use a decent quality wire, My own G3 ran without a mosfet for the first couple of shoots. I only put one it because I wanted to change the way the loom fitted in the stock. The original one was a little short for my liking, and was using mini tamiya rather than deans. I also had to open the box because I had a poor airseal. Those factors meant that it was the correct time to add a fet. Gearbox open, soldering iron out. Whilst I replaced most of my loom with silver plated wire to increase the length, I left some of the LCT wire between the motor and mosfet as it fitted nice, and I didn't feel it was of a poor quality. In time I will replace all of it, But now that most of the work is done that isn't going to be for at least a year unless I have a gearbox failure before then.

 

[Adolf Hamster]

lipo's are fine without a mosfet as long as you remember the moment you start losing rate of fire to stop shooting, draining them completely isn't dangerous but it will kill the battery if the voltage drops too low which a decent mosfet will prevent with a cutoff. contact arcing is a problem 6 months down the line but it's only if you've got a unicorn gun that new contacts will be hard to source is it really a worry.

 

however a proper balance charger setup is a must, personally i'd also reccommend a checker because knowing each cell's voltage is the best peace of mind (especially when a charger fails and doesn't charge one of the cells, or you buy a brand new battery that one of the cells doesn't register, it happens)

 

sitting duck is bang on about using deans, i feel sick every time i see a tamiya connector still in use. seriously deans is better in every single way compared to tamiya. the only thing worse than tamiya connectors is tamiya connectors on an nimh, seriously this isn't 1995 we have better options now.

[Iceni]

45 minutes ago, Adolf Hamster said:

draining them completely isn't dangerous

Actually it is, It's as bad as overcharging them.

The chemicals become unstable if discharged too low I think it's about 2.8v per cell. The battery won't explode right away, It'll wait till you try and charge it, then burst into flames on the charger.

Your gun will be very slow at this point. 5.8v on a 2cell battery. It'll probably refuse to shoot before this but it's best to whip them out when you start to feel the drop off in performance, It will happen at a voltage that is safe.

A lipo discharge has a curve that looks like this. You'll notice the fall  off starts when a cell hits about 3.3v, and is still in the very safe zone.



Most good chargers will refuse to charge a lipo that has been discharged to a voltage low enough to make it dangerous to charge again. You should never try to trick a charger into charging a lipo it has refused to charge.

It falls into safe lipo use, Trust the charger when it says no.

 

[Adolf Hamster]

13 minutes ago, Iceni said:

Actually it is, It's as bad as overcharging them.

The chemicals become unstable if discharged too low I think it's about 2.8v per cell. The battery won't explode right away, It'll wait till you try and charge it, then burst into flames on the charger.

Your gun will be very slow at this point. 5.8v on a 2cell battery. It'll probably refuse to shoot before this but it's best to whip them out when you start to feel the drop off in performance, It will happen at a voltage that is safe.

A lipo discharge has a curve that looks like this. You'll notice the fall  off starts when a cell hits about 3.3v, and is still in the very safe zone.



Most good chargers will refuse to charge a lipo that has been discharged to a voltage low enough to make it dangerous to charge again. You should never try to trick a charger into charging a lipo it has refused to charge.

It falls into safe lipo use, Trust the charger when it says no.

 

 

huh the more you know, i always thought it was a case of it kills the battery but doesn't make it explode the same way overcharging does.

 

regardless, as you say proper charging gear you can trust is the best defence.

[emilianoksa]

18 hours ago, Iceni said:

You can get away without one. The worst a 7.4 will do is blacken the contacts a little, It's nothing to worry about. The only reason you might want a fet is for the lipo protect. When a lipo discharges you firstly get a steep drop in voltage for the first few shots, then it levels out and stays level for most of the discharge, Then at the very end it will start to noticeable drop off again, the gun will shoot less rounds per second, and the trigger response will be slower. This is when you change them, NOT when the gun can no longer shoot!

Getting 2 decent capacity batteries and swapping at lunch is as good a failsafe as any.

 

 

 Yes, without a problem. LCT use a decent quality wire, My own G3 ran without a mosfet for the first couple of shoots. I only put one it because I wanted to change the way the loom fitted in the stock. The original one was a little short for my liking, and was using mini tamiya rather than deans. I also had to open the box because I had a poor airseal. Those factors meant that it was the correct time to add a fet. Gearbox open, soldering iron out. Whilst I replaced most of my loom with silver plated wire to increase the length, I left some of the LCT wire between the motor and mosfet as it fitted nice, and I didn't feel it was of a poor quality. In time I will replace all of it, But now that most of the work is done that isn't going to be for at least a year unless I have a gearbox failure before then.

 

 Iceni, thanks for your input. I know this is off topic but since you own an LCT I thought I would bring it up.

 

When I asked the retailer if I should wipe the steel externals over before storage with a lightly oiled cloth eg  Ballistol, or use a silicone cloth instead, he told me not to bother with either.

 

He said he had never seen rust on an LCT, that the finish on them provides plenty of protection,  and that putting gun oil or silicone on the steel would be a waste of time. He advised me just to use a clean dry cloth to remove dirt and finger prints.

 

Has that also been your experience?

[Careless]

49 minutes ago, emilianoksa said:

 

you dont want your AK to rust???? seriosuly it would look amazing! {if done right}  all weathered an worn and rusty! , prestine airsoft guns dont look right imo ,

 

[Iceni]

I oil mine.

I use a mixture of silicone oil with a PTFE additive. It seems to protect well, and has the added bonus of leaving a slightly non stick surface on the gun.

I wipe it down about once a month, mags as well as mine are steel.

At £5 for 100ml it's good value.

https://www.ebay.co.uk/itm/synthetic-Oil-With-PTFE-Air-Rifles-Air-Soft-Paint-Ball-100ml-bottle/172160274050?epid=1459041051&hash=item28158d4e82:g:gzcAAOSwB2RZytI6

The same seller does a PTFE Silicone grease that I like as well in some really nice little pots. It's good for O-ring seals.

https://www.ebay.co.uk/itm/HIGH-TEMPERATURE-SILICONE-GREASE-WITH-TEFLON-PTFE-50g-TIN-MFP-2HT/172122845579?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D50545%26meid%3D83886f795b1d4e219d4d8f4eef6e69d7%26pid%3D100005%26rk%3D2%26rkt%3D3%26mehot%3Dag%26sd%3D172445549313%26itm%3D172122845579&_trksid=p2047675.c100005.m1851
 

[emilianoksa]

On 5/8/2018 at 8:26 PM, Prisce said:

I use 7.4s all the time, not as dangerous as everyone makes out. As long as you use common sense and diligently look after your batteries you will be fine. 

 

I recommend this, get yourself a couple of turnigy 7.4 lipos from hobbyking or somewhere similar. Get yourself an IMAX B6AC, it will charge the batteries, and allow you to constantly monitor the condition of them, and allow you to discharge them when not in use.

 

Then for storage, if you really are a worrier, an old ammo tin, or storage tin, and when your not in, put the batteries in here and put them in the bath tub, keep them away from flammable surfaces.

 

For the batteries, charge them when you want to use them, when you get home, put them back on the IMAX into storage charge.

 

The lipos only go bang when you mistreat them. Treat them with respect and you will be fine.

 Prices in the UK are all over the place for the above battery charger.

 

£19 from here: https://www.rcmoment.com/p-rm165.html?currency=GBP&Warehouse=CN&aid=rmplagbtjc&gclid=EAIaIQobChMI34ugwLv92gIVyqsYCh1XFw21EAQYBCABEgKTOvD_BwE

 

£32 from here: https://hobbyking.com/en_us/imax-b6ac-v2-professional-balance-charger-discharger.html?countrycode=GB&gclid=EAIaIQobChMI34ugwLv92gIVyqsYCh1XFw21EAQYAiABEgKcOPD_BwE&gclsrc=aw.ds

 

A whopping £67 from here: https://www.reichelt.com/gb/en/?LANGUAGE=EN&CTYPE=0&MWSTFREE=0&CCOUNTRY=447&ARTICLE=182805&PROVID=2788&wt_guka=55294655038_263512498539&PROVID=2788&gclid=EAIaIQobChMI34ugwLv92gIVyqsYCh1XFw21EAQYBSABEgL7x_D_

 

And so on.

 

Are these really the same batteries or are there fakes on the UK market.

 

What's the difference between v1 and v2?

 

[Prisce]

There are fakes. Lots of them. Hobby king are your best bet, and I believe if you stay on the page just looking at the item the price drops a tad..(can someone verify)

 

Search for Genuine IMAX B6 AC charger and you should get some better hits. The place I purchased mine has gone out of business so I can’t recommend them!