9v and 7.5v battery OK to be in parallel?

Mario · Post by **Mario** » Thu Oct 09, 2008 9:03 pm

I'm building an N64 portable and I was going to have two batteries for it: a internal 9v battery and a 7.5v external clip-on battery. Will these two be able to work in parallel?

eurddrue · Post by **eurddrue** » Thu Oct 09, 2008 9:06 pm

well you could use one battery to power your psone screen and the other to power your n64. thats what ben did in his first atari. It would work because psone takes 7.5v and n64 takes 9v so as long as they have the ampereage to power each one alone then you could do that.

Mario · Post by **Mario** » Thu Oct 09, 2008 9:11 pm

Yeah, but the 7.5v battery is supposed to be optional. You can take it off for less weight, of put it on for more battery life.

Valium · Post by **Valium** » Fri Oct 10, 2008 4:30 am

No, not in parallel, they have to be the same voltage in parallel or else they'll go haywire. No telling what will happen then.

Rekarp · Post by **Rekarp** » Fri Oct 10, 2008 8:29 am

Valium wrote:No, not in parallel, they have to be the same voltage in parallel or else they'll go haywire. No telling what will happen then.

The 9V battery will try to charge the 7.5V battery causing it to become overcharged and probably resulting in a goo of battery acid.

Valium · Post by **Valium** » Fri Oct 10, 2008 1:52 pm

Rekarp wrote:
Valium wrote:No, not in parallel, they have to be the same voltage in parallel or else they'll go haywire. No telling what will happen then.
The 9V battery will try to charge the 7.5V battery causing it to become overcharged and probably resulting in a goo of battery acid.

See? That doesn't sound good at all.

Mario · Post by **Mario** » Fri Oct 10, 2008 7:37 pm

Any ideas on how I can drop the 9v battery's voltage without too much mA loss?

bacteria · Post by **bacteria** » Sat Oct 11, 2008 5:24 am

Why not just use a two pole switch to select either the built-in battery or the external one? 9v is at the maximum of the PSone screen (if that is what you are using), I am sure you know that...

hailrazer · Post by **hailrazer** » Sat Oct 11, 2008 5:29 am

bacteria wrote:Why not just use a two pole switch to select either the built-in battery or the external one? 9v is at the maximum of the PSone screen (if that is what you are using), I am sure you know that...

Actually it's 8.5v

Mario · Post by **Mario** » Sat Oct 11, 2008 10:05 am

Well, let me explain my story better.

I want to have an internal battery pack on my new portable. I found a universal 5400mAh battery pack on eBay (the universal ones have a charge protection circuit built in). 5400mAh will only give me about 2.3 hours of battery life, so I want to put a clip on the back that can take an optional sony camcorder battery. So you could choose between lightweight or lots of battery life.
The universal battery is 9v, but the sony batteries are 7.5v. What do I do?

(Or, does anybody know of any 7.5v DVD player batteries with built-in charge protectors?)

Mario · Post by **Mario** » Sat Oct 11, 2008 12:05 pm

Okay, nevermind. I decided to get a different battery that is 7.5v. It has less mA, but it still should give a decent play time. Thanks anyways!