Daystate battery question

[Phil Russell]

Daughter's AirWolf, an early model having a 9.6v plug in battery, refused to fire today. It had a new battery about 4 yrs ago and has been charged every month or 6 weeks since. Last recharge was 5 days ago. I checked voltage today and it registered 7.7v. Red light is on but total refusal to fire. No beeps either (but fair enough it only beeps after the shot).
I suspected the battery so rigged up a PP3 onto the original battery plug. Success ... rifle fires and beeps as it should; so new battery it is. I thought of staying with the PP3 or better 9v option but it would mean stock work to get it to fit so ordered a new 9.6v battery.
Wow ... talk about an arm and a leg! Including post, near on £45.
Now a question, just curiosity. The 9.6v battery is rated at 400mah (I think) yet a newer type 8.4v one is rated at 800mah, I think. The question: Can an 8.4v battery be used as a replacement for the 9.6? I guess the 8.4 type would have more capacity and the greater capacity could be a good thing to maintain battery life. (am I talking rubbish?). But maybe the earlier circuits need the 9.6v and so would not perform as well or as consistently with the 8.4v pack. (more rubbish?)
Just curious and maybe the electronic wizards out there can dive a rational answer to the question.
Cheers, Phil

[Turnup]

Branded replacement battery packs are always a rip off.

It might work or it might not. You already know that the unit will not function at 7.7v (BTW that is very low for a nominal 9.6v battery - sure it is charging correctly?)

8.4v is quite a bit less than 9.6 so even if it does work, it might not last long.

Can the battery pack be disassembled relatively easily? There will be a stack of cells in there and these can be purchased relatively cheaply. Get the same type (NiCad/LiPo/NiMh or whatever) and the charger will still be good too.

[Phil Russell]

Branded replacement battery packs are always a rip off.

It might work or it might not. You already know that the unit will not function at 7.7v (BTW that is very low for a nominal 9.6v battery - sure it is charging correctly?) It was 7.7 when I tested it after the rifle failed to fire. I can only assume that the battery lost voltage before, or during the last recharge a few days ago. I have known this happen before when suddenly a couple of cells give up.

8.4v is quite a bit less than 9.6 so even if it does work, it might not last long.

Can the battery pack be disassembled relatively easily? Short answer, no. The stack of cells have been either soldered or tag (?) welded together to form a neat stack. There will be a stack of cells in there and these can be purchased relatively cheaply. Get the same type (NiCad/LiPo/NiMh or whatever) and the charger will still be good too.

I have been down the rebuild route before and decided it was not worth it.

Still think the new battery pack is a rip off.
Cheers, Phil

PS tried to highlight my answers to the above; clearly failed.

[Rich]

Yes the 8.4v battery with roughly double the Ah rating is a direct plug-and-play substitute. My Airwolf is about the same era as yours and I swapped out the battery maybe four years ago.

[dair]

I too have an early model Airwolf CDT with the older 8.4v system. When my battery pack went south I had a local battery specialist build me a new unit. He removed the old wiring off of the pod batteries and mated it to a new set of seven rechargeable AAA batteries (1.2v for a total of 8.4v). He said he preferred them to the pod style. They were all heat shrinked together and the over all package is almost exactly the same size as the original pod set-up. Batteries are lined up in a 2-3-2 sequence that makes a near round package and fits perfectly in the stock with no alteration. They also have a 1000 MAH rating and have been going strong for about three years now. Cost was about equal to 25 pounds Sterling which is way cheaper and the performance is much better. The best thing is the rechargeable AAA's are easy to source. The place I got mine is in the states and they go by the name of Batteries Plus or I should say their new name now is Batteries and Bulbs. I would think you have a similar type company in the UK. No need to go back to the pod style batteries in my opinion or at least the expensive factory ones. As the above poster stated make sure you use the same type battery or your built in charger won't work.

[jameswrx]

What is this daystate battery like?

Is it the blue shrink wrapped one? Like a load of AAA batteries?

Has anyone looked at the RC market to find where it originates?

[Phil Russell]

What is this daystate battery like?

Is it the blue shrink wrapped one? Like a load of AAA batteries?

Has anyone looked at the RC market to find where it originates?

It is a 'battery pack' made up of 8 'flat cells' mounted on top of one another with a plug in connection to the pcb. My MK3 uses two packs of 4 cells soldered to the pcb.
I did once track down a supplier of the MK3 cells/packs but they were in Australia.
Not thought of the RC market ...
Cheers, Phil

[jameswrx]

Flat cells sounds like a lipo battery?

I'd be pretty sure daystate just buy them in. They sound like electric RC helicopter batteries.

[airgunnut]

Flat cells sounds like a lipo battery?

I'd be pretty sure daystate just buy them in. They sound like electric RC helicopter batteries.

Flat cell lipo is just over 3v each, if it was lipo or any other lithium based battery then it would only be 3 cell, if it's 8 cell then it sounds like nimh or nicad to produce 9.6v

[Phil Russell]

Flat cell lipo is just over 3v each, if it was lipo or any other lithium based battery then it would only be 3 cell, if it's 8 cell then it sounds like nimh or nicad to produce 9.6v

They are NiMh cells. AirWolf has 8 cells in a stack with a plug in connector to the PCB, 9.6v, 450 mAh (I believe)
My old MK3 takes 2 packs of 4 cells, 600mAH, each pack soldered to the circuit board.

Out of interest I have searched for Radio Control NiMh battery packs on that site and there are several at 9.6v and around 1800mAH ones ... but all would need some work on the stock to allow fitting. Most are based on 8 x AA size batteries and cost around the £10 mark. There are a few based on AAA batteries which, interestingly, are more expensive, around £19 but from China. All would need the RC connector removing and a connector suited to the Ds pcb to be fitted; but this should not be a problem if you used the existing connector ... simply dismantle it and solder the new leads to the old connector. I found none based on the flat button type cells other than low voltage, low capacity units.
Cheers, Phil

[airgunnut]

It might be worth investing in a rc battery charger, charges all rechargeable battery types, they can also cycle the battery to try to remove the memory effect, they also tell you how many amps the battery can give and take. I got one of the bay for less than £10 deliverd (it was a copy of a good brand)