Does 'redeem' means 'borrow again' in this sentence?
[VERB] If you redeem an object that belongs to you, you get it back from someone by repaying them money that you borrowed from them, after using the object as a guarantee.
e.g Make sure you know exactly what you will be paying back when you plan to redeem the item.

So does the example sentence mean the same thing as "Make sure you know exactly how much you should repay when you plan to borrow the item again."?

Question

Does 'redeem' means 'borrow again' in this sentence?
[VERB] If you redeem an object that belongs to you, you get it back from someone by repaying them money that you borrowed from them, after using the object as a guarantee.
e.g Make sure you know exactly what you will be paying back when you plan to redeem the item.

So does the example sentence mean the same thing as "Make sure you know exactly how much you should repay  when you plan to borrow the item again."?

Answer

No. It means to buy back. It means that before you plan on using the object as a guarantee, you should make sure you know how much money you will need to pay in order to redeem it (to buy the object back).

For example, if you sell your computer to pawn shop, they will give you a loan. You have a certain amount of time in which you can pay back the loan with interest to redeem (buy back) your computer. This sentences is saying that you should know how much money you will need to pay back in order to buy back (redeem) your computer from the pawn shop.

Answer

No, the sentence is an advance warning for someone borrowing initially. The sentence is a little out of context.