Best batteries for the NXT

[hnandan]

I just started another thread ... https://sourceforge.net/apps/phpbb/mind ... ?f=2&t=855

With following content

Hi,

Does anyone has experience with using 1.6v ZiNc rechargeable batteries in the NXT brick. I am not sure if higher voltage can fry the brick.

They are much cheaper than buying the rechargeable battery pack + charger sold by Lego thus worth researching into.

These are available at AMAZON at following link:

http://www.amazon.com/PowerGenix-ZRPGX- ... pd_sim_e_3

HN

[philoo]

I am not sure if higher voltage can fry the brick.

Well, if you look at the datasheet of these cells, at the beginning of discharge curve each one provides something like 1.83V. So the LB1836M motor dirver will receive almost 11V while its absolute maximum rating is only 10.5V. I don't think it will fry, but we are on the wrong side of safety limit...

Note also that at 1500mAH their capacity is not outstanding. But of course increased voltage means higher speed and power from your motors!

[jwiger]

I need to make a capacitor the size/shape of a AA battery... five NiZc AAs will make 8-9.25vdc. I wonder if a dummy AA with a capacitor would yield any benefit?

[mattallen37]

I need to make a capacitor the size/shape of a AA battery... five NiZc AAs will make 8-9.25vdc. I wonder if a dummy AA with a capacitor would yield any benefit?

A capacitor? I don't think that's what you want at all. The NXT shouldn't even turn on (at least for more than a quick jiffy) if you put a cap in series with the batteries. A dummy should serve the purpose, but then what's the point of using those special batteries?

[philoo]

Don't see the point of using a capacitor here... Yes, a fake battery (shorted between terminals) + 5 Zn batteries would provide a safe voltage.

[jwiger]

Don't see the point of using a capacitor here... Yes, a fake battery (shorted between terminals) + 5 Zn batteries would provide a safe voltage.

I'll experiment with this a bit after i get moved back to the states. however I doubt there will ever be a 5 slot recharger, so it may be more trouble than it's worth, still i'm curious.

[mattallen37]

An NXT will run on three of those, and maybe only two. I once had an NXT register a voltage of something like 3.3v, so two 1.6 volt batteries with a small spike might allow it to run.