Solar Bank explanation
The Solar Bank is the sister bank of Dark Loans. It is run by Luxana and, unlike its darker counterpart, serves a much better purpose to the player.
The Solar Bank is just like a regular bank; you can deposit some sol, you can withdraw some sol, and you gain interest on your sol. For some parts of the games, the Solar Bank can be vital and also proves very helpful to the player when it comes to energy.
In Boktai: The Sun is in Your Hand, the max capacity for the solar bank is 999 sol. In Boktai 2: Solar Boy Django, the max capacity for the solar bank is 9999 soll. In Lunar Knights, the max capacity for the solar bank is 999999 soll.
 How the Solar Bank works
The Solar Bank takes sol from the Solar Station. The solar station gets sol from the player; absorbing and even just walking around in sunlight. However, sol from the solar station does not automatically transfer to the Solar Bank; you have to do that manually by going into the Solar Bank in a dungeon (Boktai: The Sun is in Your Hand), or at the mall in San Miguel (Boktai 2: Solar Boy Django).
 Dark Loans and the Solar Bank
When repayment for Dark Loans comes around (God forbid), Doomy will automatically take repayments from the Solar Bank. If you fail to meet these repayments, you will have to pay the Dark Loans penalty.
 Using the Solar Bank
The Solar Bank can't be used all that much in Boktai: The Sun is in Your Hand. It's useful for transferring sol to and from the solar station, in case you've got no sunlight for those all important boss battles.
In Boktai 2: Solar Boy Django, however, its use is much more extensive as soll is now a currency; it is used to purchase items at the various shops in the Mall. It can still be used to transfer soll to the solar station, however players may find that most of their soll is in the bank rather than the solar station.
 Cheating the Solar Bank
In Boktai: The Sun is in Your Hand it was possible to "cheat" the solar bank. You could basically earn 999 sol in 5 minutes using this trick. There are 4 easy steps.
- Deposit - Deposit about 50 sol into the Solar Bank. Switch rooms, save and turn off the game.
- Time travel - Forward the time by 1 year (just quicker). Start up the game again.
- Inspect - For assurance, check the Solar Bank just to make sure that you have 999 sol in the Solar Bank. This works because there is a fixed interest rate and since you forwarded time by a year, the interest just piles up. Switch rooms, save and turn off the game.
- Reverse time travel - Reverse time by a year (i.e. to the original date). Start up the game for the last time.
- Resume - Now you should have 999 sol even though you reversed time. After all, why would they take sol away?
This trick is handy when you're in a sticky situation for sol. You can do this as many times as you want, and so you can even fill up your solar station by doing this process twice; just switch around the amount in your solar station with the amount in your Solar Bank.
 Lunar Knights Solar Bank
In Lunar Knights the Solar Bank is run by Laura. The principals of the Solar Bank are basically the same as they were in Boktai 2, in that soll is a currency and is kept in the bank. You can transfer this soll into the solar station.
However, the Solar Bank has an additional feature. Since there is no warehouse in the game, you are now able to keep all your items in the Solar Bank. Unlike the warehouse, you do not need keys to unlock extra spaces for storage. You have 4 pages for item storage and 4 pages for accessory storage.