Combining battery to get higher Volt and AH?

Hi, I have a another noob question,

Is it okay to add different volt/ah in a serie?

For example, I have a 36v 15ah lifepo.

Will I be able to add 24v, 30ah battery to make it 60 volt and however many amp hours?

Another scenario is to add same volt but different ah. I.e. 36v and 25ah (on top of 36v, 15ah) to make it 72v, 20ah.

Thanks for your help.

Yes you can series different capacity batteries, however, they will be discharged at different rates.

This means that your capacity is limited by the smallest cell in series eg. using your example, your 36V 15Ah battery will be fully depleted when the 24V 30Ah battery will only be half depleted.

Therefore that gives you effectively a 60V 15Ah battery.

The other scenario will result in a 72V 15Ah battery.

You will also need to charge each battery separately i.e. use a 36V & a 24V charger or for the 72V pack, use two 36V chargers.

Thank you. Now I know what to buy (or what to sell and to replace).

Cheers