[Pbandjelly]

I have just made a battery pack with two sets of four batteries in parallel combined to make both four sets in series – I know there is a proper name for this but I don't know what  it is. I have a lithium ion charger and I don't know if I can carve it as it only goes up to three cells but do the two parallel cells work as two instead of the eight total cells used?

[Borek]

Don't charge the lithium batteries out of the spec of the charger, that's asking for troubles. I would charge batteries separately.

[Pbandjelly]

But they are all soldered together in a pack do I have to take them apart every time I want to charge it?

[Borek]

But they are all soldered together in a pack do I have to take them apart every time I want to charge it?

Have you soldered them by yourself (if so, you have just created a problem), or are you using a multicell pack? At least some multicell packs (like those used to propel RC models) have additional connector that are used for battery balancing. But that requires a specialized charger.

[Pbandjelly]

I did but I can desolder them but i didn't want to

[Enthalpy]

Don't put batteries in parallel, that's an avenue to big problems, from zap to boom. The resulting corrosion and fire are dangerous with lithium-ion batteries.

The two parallel packs in series create a voltage equal to two cells in series.