Battery Holder conversion

[tbone1993]

Full disclosure this doesn't have to do with flashlights but this sub forum seems to be the best spot to answer my question. I've got a mechanical decoy that runs off of 4 double AAs in a harness (see image). I want to build something that will allow me to get a longer run time than burning through AA's or using rechargeable batteries. The connection looks to be similar to that of a 9volt battery. I was wondering if someone knew the correct battery I could run without burning out the motor on this thing or over powering it. There isnt much room inside the decoy so I wouldn't be opposed to running a length of wire to a battery box on the ground. My first thought was somehow connecting a power bank for a cell phone via a usb to the decoy. I just don't know how to do it. I'm not sure if it this adapter is in series to get more volts or if its just in parallel to get more run time. Is there such a thing as a usb to 9volt connection?

 

[Lynx_Arc]

There is no premade USB adapters for this as USB is 5V and this is most likely a 6V adapter. There are some 6V devices that will operate at 5V but you would have to try it and see if it actually works at that voltage. If is does work at 5V you could use a power bank but beware power banks differ if the load is too low in current some won't turn on and some that turn on won't stay on for long. If you are somewhat savvy they do make circuits that can boost voltage and you can adapt this to either bare batteries of some sort or a power bank as I've used a boost circuit to run a 9v boom box from a power bank. You can also get buck circuits and use higher than 6v battery sources perhaps a set of 2 lithium ion cells in series for 8.4v (7.4 nominal). One other alternative is a 6v lead acid battery

 

[LED_astray]

I'd think this would better fit in the Electronics & Batteries section, there may be ideas available there.

But, given your questions, I think getting (now-)Panasonic Eneloops is your best solution. CostCo regularly has a kit which is a good deal when on sale. (OK at other times. Folks have reported catching sales at Walmart & Amazon too.) The Eneloops should fit, be the correct voltage, and be sustainable. It will depend on the load your decoy puts on the batteries, but I wouldn't be surprised if a charge ran as long as disposable AAs.

 

[alpg88]

you can use 4d cells holder, or 6v lantern battery (which is really 4d cells in a a case.), you will need to come up with a new way to connect, or you can get another 9v clip, and use it to clip into your existing one and connect new one to battery outside.

 

[fivemega]

In most cases each alkaline or NiMH cell is working at 1.2 volt under load (4x1.2=4.8) and time to replace or recharge at 0.9 volt each (4x0.9-3.6)
If this is true for your devise, your best choice will be a single Li-ion 26500 or pair of parallel 18500
So, please test your devise with single Li-ion (3.7 Volt) or 3 rechargeable AA (3.6 Volt) to make sure works fine then measure maximum space of battery compartment. :twothumbs

 

[alpg88]

his device has a motor, they are usually not that good with lower voltage input. may not have enough power to do what it was designed to do.

 

[fivemega]

his device has a motor, they are usually not that good with lower voltage input. may not have enough power to do what it was designed to do.

And that's why I suggested to test first. Testing is free and you will earn experience.
I had a table fan powered by 4 "D" size alkaline. I converted to pair of parallel 26650
Blade speed was little slow but good enough for it's job.