Batteries In Parallel To Increase Playtime?

[bacteria]

I was reading an article:

article

Batteries are normally linked together in series (two batteries = 2x voltage of a single battery), as they are on the GP2x. The article is talking about parallel connecting - the GP2x drains batteries, we all know that. My thoughts are - if we connected an external (home made) battery pack, made up of 6 batteries, (two sets of three battery sets in parallel), this would appear to keep the same voltage as we currently get, but could, in theory, give us 3x the play life between recharging, so we could get about 15 hours on 6 batteries (or whatever multiplier of battery packs you want to use) - maybe more, as the combined power of 3x 2600Nimh batteries would be very high, whilst still maintaining the same voltage of a single battery.

I don't know if this would work in practice, perhaps someone could enlighten?

I know this would mean an external battery pack, but it is still a better option than the power mains adaptor (which gets in the way of the GP2x buttons). The battery contacts could be easily soldered to the existing GP2x battery contacts, on the underside of the GP2x.

 

[Gadget]

I was reading an article:

article

Batteries are normally linked together in series (two batteries = 2x voltage of a single battery), as they are on the GP2x. The article is talking about parallel connecting - the GP2x drains batteries, we all know that. My thoughts are - if we connected an external (home made) battery pack, made up of 6 batteries, (two sets of three battery sets in parallel), this would appear to keep the same voltage as we currently get, but could, in theory, give us 3x the play life between recharging, so we could get about 15 hours on 6 batteries (or whatever multiplier of battery packs you want to use) - maybe more, as the combined power of 3x 2600Nimh batteries would be very high, whilst still maintaining the same voltage of a single battery.

I don't know if this would work in practice, perhaps someone could enlighten?

I know this would mean an external battery pack, but it is still a better option than the power mains adaptor (which gets in the way of the GP2x buttons). The battery contacts could be easily soldered to the existing GP2x battery contacts, on the underside of the GP2x.

Yes, this would indeed work.

 

[degziebob]

So there's nothing to stop someone making a fake insert for the battery compartment with a wire coming out of it into a breakout box that has several batteries in it ... hmmmm

 

[Fishbong]

It would work. But you better don´t try doing it with rechargeables.

I just recommend doing it with non - rechargeable batteries. The reason why they are drained so quick in the GP2X is that the GP2X draws too much current, and alkaline batteries die very quick if they have to deliver much current (if you want to get the maximum out of an alkaline battery, you have to draw the current slowly, like in a clock or a remote control).
However, if you arrange, say, 2 batteries parralel (that means for the gp2x, 2 arrays of respectively 2 batteries), the current drawn from each battery is only half as much, this does not double the batteries lifetime, but can actually quadruple it- or even more!

As i mentioned before, the usage of rechargeables is a bit more complicated. I don´t recommend switching them parallel, because there are current flows between them. This is due to slightly varying capacities and power of the batteries, you can´t avoid this, there´s always a little tolerance.
This can result in one battery charging the other with way too much current, or voltage inversion. Very soon the weaker battery will quickly lose capacity.

So you can use rechargeables, but it will kill them sooner or later.

I made a battery pack that can also be used with Rechargeables. I switched 4 batteries in series and regulated the voltage down to 2,8 V using a simple selfmade circuitry based on the LM2576 Stepdown Voltage regulator chip by National Semiconductor (Datasheet here).

 

[bacteria]

Just a thought - the official GP2x case could probably hold about 10 rechargable batteries and have enough space to house the battery compartments. Using this case would make everything look "official", and would be easy to get into (the case has a zipper to open it up).

These 10 batteries could give 5 batteries in twin parallel to give about 12500Nimh in total (same voltage) - about 25-30 hours playtime(?).

The two wires for the battery connections (in the case) could be connected to a female stereo connection, and the two wires soldered to the GP2x battery compartment on a male stereo connector - connect this dual wire into each other and you have power to the external battery pack.

Feasible? Comments?

 

[ste_167]

Coming soon..

Seems a bit big mind.. could it be done with four batteries?

 

[bacteria]

It would work. But you better don´t try doing it with rechargeables.

I just recommend doing it with non - rechargeable batteries. The reason why they are drained so quick in the GP2X is that the GP2X draws too much current, and alkaline batteries die very quick if they have to deliver much current (if you want to get the maximum out of an alkaline battery, you have to draw the current slowly, like in a clock or a remote control).
However, if you arrange, say, 2 batteries parralel (that means for the gp2x, 2 arrays of respectively 2 batteries), the current drawn from each battery is only half as much, this does not double the batteries lifetime, but can actually quadruple it- or even more!

As i mentioned before, the usage of rechargeables is a bit more complicated. I don´t recommend switching them parallel, because there are current flows between them. This is due to slightly varying capacities and power of the batteries, you can´t avoid this, there´s always a little tolerance.
This can result in one battery charging the other with way too much current, or voltage inversion. Very soon the weaker battery will quickly lose capacity.

So you can use rechargeables, but it will kill them sooner or later.

I made a battery pack that can also be used with Rechargeables. I switched 4 batteries in series and regulated the voltage down to 2,8 V using a simple selfmade circuitry based on the LM2576 Stepdown Voltage regulator chip by National Semiconductor (Datasheet here).

Excellent feedback - this is the beauty of forums!

Ok, use standard alkaline batteries then. You can buy these type of batteries cheaply. I live in the UK, we have lots of cheap "Pound" type shops. for £1.49 I got a pack of 24 AA Powercell super heavy duty batteries!

Fishbong (or anyone else) - rechargable batteries are 2.4v each (totalling 4.8v in the GP2x). Alkaline batteries are 1.5v each. We can use 2x alkaline batteries (c. 15 mins use) in the GP2x, so does this mean that the GP2x runs happily on 3v (alkaline) or should we use ideally 3 sets of parallel batteries (3x 1.5v - 4.5v). Comments? I don't really want to use special resistors or whatever because I don't know enough about electronics.

Coming soon..

Seems a bit big mind.. could it be done with four batteries?

Interesting - is this going to be an official product, or are you referring to a battery block currently available? Please elaborate.

Is it a block of 6 because the GP2x takes 4.8v by two rechargables, and 3x 1.5v (alkaline) = 4.5v? Comments?

 

[Fishbong]

rechargable batteries are 2.4v each (totalling 4.8v in the GP2x). Alkaline batteries are 1.5v each.

No. Alkaline batteries are 1.5 V and rechargeables are 1.3 V.

And the reason why alkaline ones only last about half an hour is that they die quickly if they have to deliver much current at a time.
Actually alkaline matteries have as much capacity as say, a 2500 MAh rechargeable, they just can´t deliver it that fast for more than half an hour.

Oh, and don´t buy those extremely cheap alkalines. They usualyy are pretty old and have therefore lost capacity.

 

[ste_167]

sorry, don't want to begin rumours.. it was just a made up pic of what could be..

The original is here though (scroll down):
http://www.card-media.co.uk/xsdrive+pro+vp3310.htm

 

[bacteria]

rechargable batteries are 2.4v each (totalling 4.8v in the GP2x). Alkaline batteries are 1.5v each.

No. Alkaline batteries are 1.5 V and rechargeables are 1.3 V.

And the reason why alkaline ones only last about half an hour is that they die quickly if they have to deliver much current at a time.
Actually alkaline matteries have as much capacity as say, a 2500 MAh rechargeable, they just can´t deliver it that fast for more than half an hour.

Oh, and don´t buy those extremely cheap alkalines. They usualy are pretty old and have therefore lost capacity.

Thanks for clearing that up.

You mention about "lost capacity" - does this mean the alkaline batteries are not at 1.5v each (so not powerful enough), or do you mean that they are but have a far decreased lifespan each, as they are cheap?

 

[bacteria]

sorry at don't want to begin rumours.. it was just a made up pic of what could be..

The original is here though:
http://www.card-media.co.uk/xsdrive+pro+vp3310.htm

Cool!

Yes, it could easily look like this, or concealed inside a box (eg the official GP2x one). I can't use the official GP2x case anymore as my GP2x (with D-pad) is a bit tight in the case, so I don't want to use it (I use a DS case instead) - so using the GP2x case as a battery pack case seems a good idea!

You can easily, and cheaply buy battery compartments from electronics stores, you can wire them up (they will need to be individual battery holders as they are sold together as serial connections (which you don't want). Alternative is to make your own; you could make a metal plate to connect the "+" terminals and another plate to connect the "-" terminals and make a mechanism to allow for easy insertion and removal. You must not solder directly to the battery terminals, as this could make the batteries explode (mentioned in the article I referred to in my first post).

 

[BenScar]

Someone mentioned that if your connect re-chargables in parallel they may well end up charging each other. I can see how that would happen.
My question would a set of diodes prevent that from happening?

I'll knock up a diagram of what I mean once I've done the washing up (yeah yeah, joke all you like ), but from what I understand it's because the "better" set of batteries would feed the other set as their + terminals are connected (as well as the - ones). If there were diodes to prevent the current going "that way" neither set could charge the other.

Am I making sense or just making it up?

Edit: Spelling and adding missing words..

 

[Fishbong]

You mention about "lost capacity" - does this mean the alkaline batteries are not at 1.5v each (so not powerful enough), or do you mean that they are but have a far decreased lifespan each, as they are cheap?

Jeez, what do they teach you at school nowadays?

Explanation for dummies:
Capacity determines how much current "fits" into the battery and it is usually measured in mAh (like 2600 mAh for good rechargeables). It also determines how long the battery lasts.

Voltage determines with what amount of "force" or "pressure" the battery can deliver its current. If a circuit has high resistance, usually high Voltage is needed to power it. Usual AA batteries have 1,5 V (Volt). The voltage of a Battery usually only decreases at the very end of its lifetime.

Summa summarum: Those cheap batteries have often lost lots of capacity due to long storage. This will cause them to have a shorter "lifetime".

 

[Gadget]

Someone mentioned that if your connect re-chargables in parallel they may well end up charging each other. I can see how that would happen.
My question would a set of diodes prevent that from happening?

I'll knock up a diagram of what I mean once I've done the washing up (yeah yeah, joke all you like ), but from what I understand it's because the "better" set of batteries would feed the other set as their + terminals are connected (as well as the - ones). If there were diodes to prevent the current going "that way" neither set could charge the other.

Am I making sense or just making it up?

Edit: Spelling and adding missing words..

I was just thinking that myself. Basically each battery has a diode leading to the + terminal. If all the batteries in Parallel have a diode there, it should stop any reverse leakage. In theory you could have 100 batteries in parallel, but the potential for high current increases! This may be particularly important to overclockers, you may be able to overclock higher, BUT the risk of damaging the device increases with each pair in parallel.

 

[Javacat]

I think a few people have already created external power packs for there GP2X's using various different wiring techniques, although I can't remember who the people are.

 

[QuasaR]

Why not using Monos instead of Mignons... I've seen some with over 5000mAh => resulting in 10000mAh with just 2 batteries...

 

[BenScar]

Why not using Monos instead of Mignons... I've seen some with over 5000mAh => resulting in 10000mAh with just 2 batteries...

You lost me, what's a "mono" or "Mignons" ?
Types of battery are they?

 

[Series-8]

The Europeans call "AA" Lr-6: R06, MN1500, AM3, UM3, Mignon

And 'D' cells: R20, MN1300, UM1, or Mono

Also they like to call cells Accumulators too...

A 'AA' by any other name is still a lousy energy source.
GET LITHIUM ION POLYMER! (smaller, lighter, higher voltage, faster charges, Mo' energy)

 

[DTH]

How is it possible to get these bulky batteries in the system then?

 

[Gadget]

How is it possible to get these bulky batteries in the system then?

Buy one of the holding cell things (like the ones shown on page 1 of this thread), and connect the + and - directly into the battery contacts in the GP2X, or into the power in socket.

You could have a 'box' that you can just plug into your GP2X and get many more hours of power. As I said earlier though, the maximum current available to the GP2X could cause problems if you are overclocking and the CPU(s) go into a lock / crash situation from excessive heat etc. At that point they could drain a LOT more current than normal, and with standard batteries that might not be a problem, but when there is a possibility of LOADS more current than normally possible through the battery connectors, you could damage something.

Personally I would think about adding a fuse inbetween the high power batteries and the GP2X, but someone needs to work out what a good size fuse would be in mA. ie. at 200Mhz, or under extreme load at 275 - 300 Mhz.

Has anyone checked the sort of current that the device uses under normal / overclock?


EDIT: http://www.all-battery.com/index.asp?PageA...PROD&ProdID=568