Batteries are recharged!

So, with the release of Duelist Alliance, Batteries have made a huge comeback. They are a budget friendly deck that can make extraordinarily strong plays.  It can special summon multiple monsters per turn, destroy front and back row, bounce things, has self buffing effects, and can clear your opponent's entire board. And now, they can search super consistently. I think the deck can even be competitive for those who would want to bring something to Regionals or a locals. Now, onto the why and how.

Batteryman 9-Volt
This is the new dude who makes it all possible. When he is summoned, you can go add another Battery to your hand. And then he becomes a 2000 ATK and DEF level 4. This effect is optional, so be careful, not searching results in him not getting his buff. Only down side to him is he dies during your end phase. Which could be taken as a good thing if you have Industrial Strength in hand. And it's YOUR end phase. So if you special summon him during your opponent's turn, you keep him until the end of YOU turn, allowing you to have tribute fodder for the level 5-6 batteries.

Batteryman Micro-Cell
This is the batteryman that allows the deck to be consistent without 9V, but much less so. Flip effect let's you special summon another Battery. When dies by battle after being flipped, you draw a card. That means this card can get you up to a +2. (special 9V, add to hand, then dies and draws a card is a +3, his death is a -1, results in +2 overall).

Batteryman Charger
The level 5 guy. When he is normal summmoned, special summon another batteryman (except Charger). And this is not level gated, so he can special summon any battery regardless of level (except for himself and Industrial Strength because IS says so). And, he gets +300 ATK for each Thunder monster you have, including himself. So he's really a 2100, which is nice.

Batteryman Fuel Cell
The free Level 6, the (almost) cyber dragon of the group. If you have 2 batterymen, you can special summon him for free. And he is 2100. And he let's you sac 1 other battery to bounce a monster. Get's around a lot of destruction effects and anti destruction effects. Still searchable by 9V and Charger.

That is the monster core that should be maxed out, or no less than 2 of each of those. They make the deck run smoothly. Other cards:

Batteryman Industrial Strength
The top end of the batteries is Industrial Strength. Level 8, 2600 attack. Fairly easy to summon just by banishing 2 batteries. And he has another effect of banish another battery from grave to pop a monster AND a spell/trap.

Batteryman AA
The old main man of Betterymen. He is a 0/0 level 3 who was the center piece for the old OTK. His effect is odd, but powerful. With 3 of him, and Short Circuit, you usually just win.

Batteryman AAA (no links... I've gotten lazy)
A rank 4 machine. He used to be awful. His effect let you special another AAA from hand or grave. But No attack, no defense, no real reason to use him. Now that XYZ are a thing, he is an easy rank 4. But not what we want in a pure deck.

Batteryman C
Gives machines a 500 boost... what? Why? is bad.

Batteryman D
0/1900 level 1. Makes your opponent attach him before they attack another batteryman. Still bad. Stats are awful.

Of these, I can only recommend Industrial Strength. Others are sub par. Now for the spells and traps. There are 2 and only 1 trap.

Short Circuit
The OTK maker. With 3 batteries, destroy your opponent's field. The WHOLE field. Very nice, but can be dead pretty easy.

Quick Charger
Quickplay Spell that adds 2 weak batteries from grave to hand. Not bad, but better for AAA.

Portable Battery Pack
A double Call of the Haunted. Can give some serious advantage, or make Short Circuit easier to use. But needing 2 batteries may be a hindrance if you are going for Industrial Strength.

That's all the direct batteryman support that's around. There are other things can be used of course, but this is just the base batterymen stuff.

Other cards that can be added or used. (No links. Very lazy. Google if you don't know what it is) There are more, but these are the ones that I see as the best to use with.
Honest
Thunder Sea Horse (for AAA uses)
Monarchs + Monarchs Storm Forth
Call of the Haunted
Thunder King Rai-Oh
Inferno Reckless Summon (goes with AA)
Solidarity (all thunder)
Judgment of Thunder

Sources:

If you want to build the old AA OTK then yes he is. But with 9V out, the deck is really consistent, and AA is a fragile and fairly useless card without Inferno Reckless. And then he is easily stopped without Short Circuit.

More Fuel Cell than Industrial. Industrial Strength feels more like a tech choice to me than a required monster. I compare him to (a weaker-ish) BLS. Requires set up to summon, but has nice rewards if you get him out.

The OTK is still there. Since Fuel Cell is free, and searchable by 9V, you can get 3 strong dudes out without needing Inferno Reckless.

ex: Summon 9V, fetch Charger. Then on your next turn, use Call of the Haunted or Battery Charger to bring back 9V, which fetches Fuel Cell. Tribute Fuel Cell for Charger, who special summons another 9V, who fetches another Fuel Cell. You can now ss both Fuel Cell if you wish giving you over 8000 damage, and you can activate Short Circuit if you have it. Or use Fuel Cells to bounce stuff to get through. Or go into Powerful XYZs like Photon Bouncer or Gauntlet Launcher.

Batteries without AA can play the grind game better, while still pull out OTKs. AA opens you up to weak hands or plays because he is only good with himself, and bad otherwise. Same with Inferno Reckless. It could summon AA, Microcell, and 9V (which would be admittedly good, so much plus). But unless you have short circuit, it could comeback to bite you because you also just gave your opponent 2 more monsters.