Super battery pack

Gamerdude · Post by **Gamerdude** » Thu May 31, 2007 6:58 pm

Hey, i just came up with an idea to power the notoriously high power N64. A back pack battery pack. I am going to take 2 sealed lead acid battery packs at 4V and 9 Ah each weighing 3 pounds (per cell) and hook them in series. Would this work. Also, to hook batteries in paraell maens to hook the positive to the positive and the negative to the negative, I remember this very faintly, I also remember older people telling me that would blow up a battery when I was little. How do you increase amprage and not voltage then if this isn't the way you do it?

johnbjuice · Post by **johnbjuice** » Thu May 31, 2007 10:02 pm

The thing would work if you hooked them up in a series (Positive to negative) as the batteries voltage would add up to 8v. I don't see why you'd use enormous lead acid batteries though...why not use enormous rechargables? For my N64p I am using 10Ah D cells in a series for power - I'll probably get a good 4-6 hours, depending.

- Juice

timmeh87 · Post by **timmeh87** » Thu May 31, 2007 11:26 pm

notoriously high power?

perhaps compared to the relatively tame NES or SNESes, but when theres xbox portables out there i dont think the N64 really holds that title.

normal, non-backpack batteries will power a 64 portable for a good few hours. and they wont break your back.

come to think of it. most people here are using normal C size batteries which hold about 3Ah, what is the advantage of a 6 pound, 4Ah lead-acid pack? if they are not deep-cycle cells, you cant even drain them past 40% without ruining them.

if you are hardcore about your power, lithium batteries are the way to go.

not to say that a backpack isnt cool or anything. or that the batteries you already have wont work. i just dont think its the best way to do it (my opinion)

anyways. answers to questions:
-yes, series gives you the 4Ah, 8v pack which is good for a portable (if they are deep-cycle batteries!)
-yes, you are right about parallel
-no they wont blow up. theres a small issue if they arent at the same level of charge; you could severely over/under-charge one of them. if you are careful it will be fine, and people do it all the time.
-yes parallel will double the capacity of your pack to 8Ah, but the voltage will stay at 4v which isnt good for anything.

john: 1Ah is half the capacity of a AA size battery, did you mean 10Ah?

johnbjuice · Post by **johnbjuice** » Fri Jun 01, 2007 1:08 pm

Yes I mean 10Ah

Oopsies. Edited.

- Juice

Gamerdude · Post by **Gamerdude** » Fri Jun 01, 2007 2:44 pm

hey thanks for the answer and I knew that method works. I just wasn't sure I could wire them up like that and leave them. will wiring NIMH cells in parallel work too. BTW I am not making an actual backpack now.

EDIT: I was not planning on actually carrying around a backpack battery, I was more thinking of using as a stationary power supply for a portable when a wall oulet isn't available (like when camping). I was also thinkg of making an extended battery pack to hook on the back of my portable (kinda like that really crappy hard drive and extended battery they make for the PSP, for $200 get a extended battery from Sony that doesn't stick out the back and order a 4GB memory stick) but I was going to make it with NIMH. Also, can't parallel be used on all battery types as long as a protection circuit is used whith a Li-ion or Li-Po cell

daguuy · Post by **daguuy** » Fri Jun 01, 2007 3:10 pm

It only draws about 1.2A max with an LED mod, so NiMH C batteries with 5Ah last 4 hours. That's what I use and it's plenty of power.

Limewater · Post by **Limewater** » Fri Jun 01, 2007 4:22 pm

Gamerdude wrote:will wiring NIMH cells in parallel work too.

No. If you wire them in parallel, you'll only get 4Volts out of your battery pack. I'm pretty sure neither your N64 nor your screen would run at 4V.

vskid · Post by **vskid** » Fri Jun 01, 2007 5:10 pm

Limewater wrote:
Gamerdude wrote:will wiring NIMH cells in parallel work too.
No. If you wire them in parallel, you'll only get 4Volts out of your battery pack. I'm pretty sure neither your N64 nor your screen would run at 4V.

What???

Get a car battery. Several hundred Ah for $50-100. Even if you only discharge it 10% at a time, thats at least a day's worth of play time.

Gamerdude · Post by **Gamerdude** » Fri Jun 01, 2007 5:14 pm

I know that. I was going to use four, hook two of each in series and then hook them together. Like this
____
cell ]
__1_] cell 3

and cells 1 and 2 and
and 3 and 4
_____ get hooked up
two ] in parallel cell 4
____ ]

get hooked in series
and 3 and 4 do too.

please excuse my crappy diagram, but i think you get the point.

vskid · Post by **vskid** » Fri Jun 01, 2007 5:27 pm

Are you talking about NiMH's? Or your SLA batteries?

Gamerdude · Post by **Gamerdude** » Fri Jun 01, 2007 5:48 pm

The diagram is what I was going to do for the SLA non-portable portable battery (so I can use my portable while camping when a car isn't available to charge my portable) but it is a general diagram of how i plan to wire up any battery packs if I need more amprage. i know it works because if you hook two batter packs in parallel this is basically what you would be doing.

I just realized my diagram turned out horribly wrong, it didn't post with all the spaces it was suppose to have, I hope everyone hear understands it though (all it was was making two two cell battery packs and hooking them together in parallel).

Gamerdude · Post by **Gamerdude** » Fri Jun 01, 2007 5:57 pm

Limewater wrote:
Gamerdude wrote:will wiring NIMH cells in parallel work too.
No. If you wire them in parallel, you'll only get 4Volts out of your battery pack. I'm pretty sure neither your N64 nor your screen would run at 4V.

What??? I know I will only double amprage by wiring batteries in parallel but what does that have to do with Ni-MH batteries and I know what i am doing, I am just getting a little bit of confomation by asking people on the forums and so they may give me their ideas so I could maybe do it better and so they can spot any flaws in my plan.

And if I was wrong about the battery wiring I didn't want my portable melted to my hands (people who have been on this forum a few months and read all the posts know where I got this phrase)

Limewater · Post by **Limewater** » Fri Jun 01, 2007 10:15 pm

Gamerdude wrote:
What??? I know I will only double amprage by wiring batteries in parallel but what does that have to do with Ni-MH batteries

From the way you wrote your question, you were asking if you could hook up two NiMH in parallel instead of the lead-acid batteries in series in your first post. Since you didn't give any specifications for these NiMH batteries, it would be assumed that they have similar specifications to the SLA's.

and I know what i am doing, I am just getting a little bit of confomation by asking people on the forums and so they may give me their ideas so I could maybe do it better and so they can spot any flaws in my plan.

I'm sorry. I was under the impression that I was responding in the exact way you specify here, giving advice and spotting a flaw in your apparent plan.

I responded to what you wrote. You seem to want responses to what you were thinking.

Gamerdude · Post by **Gamerdude** » Sat Jun 02, 2007 12:32 am

sorry about that. I am not angry or anthing and thanks for pointing out what you thought may of been a flaw in my plan. thanks for your comment, I know you were just trying to help.