Turning one Raw Dark Matter in to Skelontorim Orrthemech yields (2) Dark Matter. Once you have completed the tinkering skill quest with him you can place one Dark Matter into your toolbox to produce (5) Grain of Dark Matter. Presumably you can also now convert your own Raw Dark Matter to Dark Matter with a result of either 2 or 1.
Grain of Dark Matter (trivial 16)
Magic Item
WT:0.1 Size:TINY
Class: ALL
Race: ALL
(1) Grain of Dark Matter + (1) purchased Battery Casing 1 =
Mana Battery Class One (triv 54)
Tradeskill item
Magic Item
WT: 1.0 Size:TINY
Class: ALL
Race: ALL
(2) Grain of Dark Matter + (1) purchased Battery Casing 2 =
Mana Battery Class Two (triv 60)
Tradeskill item
Magic Item
WT: 1.0 Size:TINY
Class: ALL
Race: ALL
(3) Grain of Dark Matter + (1) purchased Battery Casing 3 =
Mana Battery Class Three (triv 68)
Tradeskill item
Magic Item
WT: 1.0 Size:TINY
Class: ALL
Race: ALL
(4) Grain of Dark Matter + (1) purchased Battery Casing 4 =
Mana Battery Class Four (triv 76)
Tradeskill item
Magic Item
WT: 1.0 Size:TINY
Class: ALL
Race: ALL
(5) Grain of Dark Matter + (1) purchased Battery Casing 5 =
Mana Battery Class Five (triv 84)
Tradeskill item
Magic Item
WT: 1.0 Size:TINY
Class: ALL
Race: ALL
To make class six battery you need to play around with Infused Dark Matter, which I didn't have. All made mana batteries had sellback price to merchant of 9gp 2sp 4cp with 85 charisma.
Grain of Dark Matter (trivial 16)
Magic Item
WT:0.1 Size:TINY
Class: ALL
Race: ALL
(1) Grain of Dark Matter + (1) purchased Battery Casing 1 =
Mana Battery Class One (triv 54)
Tradeskill item
Magic Item
WT: 1.0 Size:TINY
Class: ALL
Race: ALL
(2) Grain of Dark Matter + (1) purchased Battery Casing 2 =
Mana Battery Class Two (triv 60)
Tradeskill item
Magic Item
WT: 1.0 Size:TINY
Class: ALL
Race: ALL
(3) Grain of Dark Matter + (1) purchased Battery Casing 3 =
Mana Battery Class Three (triv 68)
Tradeskill item
Magic Item
WT: 1.0 Size:TINY
Class: ALL
Race: ALL
(4) Grain of Dark Matter + (1) purchased Battery Casing 4 =
Mana Battery Class Four (triv 76)
Tradeskill item
Magic Item
WT: 1.0 Size:TINY
Class: ALL
Race: ALL
(5) Grain of Dark Matter + (1) purchased Battery Casing 5 =
Mana Battery Class Five (triv 84)
Tradeskill item
Magic Item
WT: 1.0 Size:TINY
Class: ALL
Race: ALL
To make class six battery you need to play around with Infused Dark Matter, which I didn't have. All made mana batteries had sellback price to merchant of 9gp 2sp 4cp with 85 charisma.

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