Turbo Booster Plus vs. Ten No Koe Bank 2

[bozo55]

I want the ability to save games on my Turbo Grafx 16, and was looking at the Turbo Booster Plus and Ten No Koe Bank 2.

From what I understand, they're essentially the same, and once you add your own AV jacks on the Ten No Koe and file the sides a bit, it's just as good. 

What I'm having trouble understanding is why the Ten No Koe Bank 2 requires 2 AA batteries.  Are they truly required?  Or just a fail safe if you unplug the system for too long?

Does the Turbo Booster Plus also require 2 AA batteries? Or does it use a super capacitor or coin battery?

Edit: forgot about the AV Booster.  I'm assuming that has no save feature built in?

Thanks to anyone who can clear this up for me.

[Pokun]

Yeah I think AV Booster doesn't have backup RAM.

Looks like Ten no Koe 2 (and possibly the Backup Booster) is powered by the AA batteries: http://www.blackfalcongames.net/?p=190.
Nowadays there are low-discharge rechargable batteries however, so batteries shouldn't be a problem.

Personally I use Super CD and Save-kun with Eneloop low-discharge batteries. Save-kun takes four batteries so I just keep another four Eneloop batteries fully charged at the ready. They can be stored for years without loosing much of their charge.

[wilykat]

Those 2 does not have internal cap for SRAM chip and relies on batteries.  Turbo Booster Plus uses cap and does not need battery.

The SRAM chip is of standard design, one could simply use zero power SRAM to eliminate external battery. Or one could just hack in a cap.

[bozo55]

Thanks guys.  I was going to try to hunt down a Backup Booster version 1 but then realized just how rare they are.  I may as well buy a Turbo Booster Plus before I buy one of those.