http://www.energybay.org/valence-batteries
The Valence Battery U24-12XP 110AH@5HR above is a plug and play 24V or 12V lithium battery. It contains no BMS. It has balance connectors. Its either 12V 110Ah. Or 24V and 56Ah. So 2 needed gives 110Ah. The 24V option is perfect.
Downside? 1750 US dollars each!!! But as you can see, these can be correctly charged with the PL8, and so are plug and play. And no theres no alternatives to these!!! Unless you DIY for a third the price. As we do.