Newish Battery not lasting one full mag

[Dread]

Hey guys

I purchased a vapex 9.6v Minh battery off eBay along with a vapex smart charger. 
never used the battery on a day out, just used it in the garden a few times to test my gun. However it doesn’t even last a full mag before it dies. I put it on charge and within 5 mins the smart charger is saying it’s finished, but again it doesn’t last a mag.

i have tried turning the charger off when it says it’s full and turning it back on again. The charger then goes back to 1 red bar, and then full again in 5 mins. If I do this a few time I can get the battery to last 2 or 3 mags.

Do you guys recon it’s a dud battery it charger?

Thanks

Dread

 

[E21A]

Sounds like a fucked battery, send it back for refund 

 

[RobHedley]

I assume you mean NIHM? NIHM Batteries like NiCad have a 'memory' and will only charge up to that point. From the sounds of it you appear to have a particularly bad one. You can reset this to a degree by discharging the battery completely and trickle charging it from scratch. The best option is to get a car headlamp bulb and solder some wires to it. Connect the battery to it and leave it until the bulb is no longer lit. That way you can see when it is discharged. However in the first instance you could use your Charger to discharge the battery so then you don't have to spend any extra money. If you do this make sure you trickle charge it back up, it will take hours, and you should get majority of the life back in the battery. If that doesn't work then as @E21A said..... its fucked and you need to send it back.

Hope that helps.

 

[Dread]

Well unfortunately I couldn’t return the battery as it was past the return date, so I went ahead and ordered a different branded battery. It arrived today, plugged it into my charger and..... the same thing happens ?.

Surely the charger is faulty? Or have I ordered 2 faulty batteries on the bounce.

Is there a way to bypass the smart part of the charger? Or is it not recommend?

Thanks
Dread

 

[Tackle]

Try another charger, maybe a mates got one ?

 

[Rogerborg]

Nihm is ancient technology.

Charging is particularly problematic.  Chargers don't know what voltage the battery is supposed to be charged up to, they have to guesstimate that it's full when the battery resistance rises and the charging current drops.  Get it wrong and the charger cooks the battery, or stops charging too soon, as it sounds like yours is doing.

I'd suspect that your problem is the charger, not the batteries.  But buying more nimh tech is just shovelling money down that pit.

What I'd suggest you do is to get a SkyRC IMAX B6 charger, or close copy.  It won't run you cheap when you include a power adaptor for it, but it should do a good job of sorting out your nimh batteries, then when you buy lithium it'll do them too.  Heck, it'll charge your car lead-acid battery if you need it to, or pretty much any other battery you can imagine with some crocodile clip leads and a couple of magnets.

Putting money into nimh and dumb "smart" chargers is one of my few airsoft regrets.

 

[Dread]

Unfortunately it’s just me so can’t borrow a charger.

I’d like to go the lipo route but I’m only a beginner so it’s not an option yet as I need to learn all about upgrading, mosfets, re-wiring etc before doing so. Plus I have heard that my guns gearbox is prone to cracking, another reason to keep to Nihm batteries for now.

I shall have a look into the skyrc thank you ?

Thanks

Dread

 

[EDcase]

Yep, sounds like a bad charger.

As our Roger said, its highly recommend getting a good charger that can handle all types of batteries and take good care of them.

This seems to be the best deal I could find with a quick search...

https://www.rctoyworld.co.uk/skyrc-imax-b6ac-rapid-digital-li-po-and-nimh-battery-charger-32840-p.asp

There are lots of copies around on ebay and the like so be careful with anything cheaper as it may have questionable performance/safety.

You'll be able to keep using the NiMh batteries until you can get some Li-Po's

 

[Rogerborg]

so it’s not an option yet as I need to learn all about upgrading, mosfets, re-wiring etc before doing so

Click to shrink...

7.4v lipo will pop right in, no need to change anything.  OK, lower voltage than a 9.6v nimh, but it'll push as much or more current.  Smaller and lighter than nimh, actually cheaper at places like HobbyKing.  I'd encourage you to go lipo as soon as you can.

 

[Dread]

Thank you for linking me, I was struggling to find the right one because all I could see was eBay stuff, which I’m already wary off.

going to purchase one now, will update when it arrives.

Thanks all

Dread

7.4v lipo will pop right in, no need to change anything.  OK, lower voltage than a 9.6v nimh, but it'll push as much or more current.  Smaller and lighter than nimh, actually cheaper at places like HobbyKing.  I'd encourage you to go lipo as soon as you can.

Click to shrink...

Thanks for the info. I’m gonna get that charger which handles lipos as well, so I’ll change to 7.4v lipos when I next need a battery ?
 

would I still need a mosfet with 7.4v lipos?

 

[Monkeywrencher]

would I still need a mosfet with 7.4v lipos?

Click to shrink...

No

 

[Philby21]

With 7.4v you'll be fine, it's only when if you try and use 11.1v that you get problems like burning out your trigger or melting your wiring!

I run two of my guns on 7.4v with no mosfet and one of those is a TM Sopmod!  I have a mosfet in my G36 and run it on 11.1v but that's a looooong way from stock!

 

[RobHedley]

I second the B6 Charger. I have one of the originals that can be powered from

mains and 12v and it is still going strong. I has to be 10 years old now (Originally got it for RC planes and Helicopters).

fantastic solid bit of kit that is worth every penny. 

 

[Philby21]

My B6 has charged my batteries for my AEGs, the battery pack for my electric G36 mag, my RC cars, my RC helicopter, my Phantom 1 and I even loaned it to a friend to charge the 6V battery on a vintage tractor - worked a treat!

Basically if you can plug it into a B6 then it'll charge it.

 

[EDcase]

On our very own classifieds...

 

[Dread]

My charger finally arrived today ?

Set it up at 1.6a and left it to charge, an hour later and it’s fully charged (battery felt a bit hot though)

unfortunately it’s too late to head out into the garden and try it, but I’ll give it a test as soon as I finish work tomorrow

 

[Philby21]

Well that's sounding considerably more optimistic already, looking forward to hearing how you get on.

 

[Dread]

So I got to test my gun out this evening and I’m happy to say everything is working as it should (finally)

filled my three mags and emptied them without a problem, felt good to see what my gun can do for the first time, now I’m excited to use it next time I go.

I also put the battery back on charge to see how much it had used/how much it had left. It had used about 350a to shoot the 3 mags, so I’m guessing I’ll get 12 mags out of the battery before it’s empty, is that about right for a 1600mah battery?

Thanks

Dread

 

[Iceni]

You'll get more than 12 mags. A lot more.

The typical discharge curve for NiMH still has a sizable voltage drop at the start of the discharge.

They normally charge to about 11.5v then drop very quickly to 10v it then levels for most of the discharge to about 9v where it starts to discharge quickly again.

The 9.6v is actually the halfway point on the discharge.

 

[Rogerborg]

Set it up at 1.6a and left it to charge, an hour later and it’s fully charged (battery felt a bit hot though)

Click to shrink...

Nihm is prone to that.  You want to charge at 1C as it makes it easier for the charger to spot the current drop that indicates charging is complete, but that does put heat into the battery, especially if it was almost fully discharged.  Plus, there's always that frisson of the charger not knowing what voltage it's supposed to be charging to (unlike with lipo/life), and the potential for it to run away.

The good news is that you've got two batteries now which should hopefully work.  I'd swap over at lunch so as not to over-discharge either.  Nimh does work fine, but if and when you switch to lipo, you'll find they're smaller, lighter, less haphazard to charge and can provide more power, even at a lower voltage.  The nimhs are likely to be relegated to backup or loaner batteries, which is no bad thing.