We use the YTZ10 Case format for our version battery to replace the lead acid Yuasa YTZ-10 YTZ-12 and YTZ-14. The reason we can't make our Antigravity any larger is because a maximum 12-Cells only fit into any of those cases. So we chose the smaller YTZ 10 case format which is the most compact of them all yet still fits the 12-Cells...the only difference between all the cases mentioned is the height. S we can offer a more compact battery if needed yet produce more power than the larger models..... Also keep in mind the YTZ 14 though is may seem like it is a bigger battery than the YTZ10 or YTZ12 is actually only .2 (2/10ths) of an amp hour more than the YTZ12 and only has 20 more cranking amps at 230 Cranking amps compared to the 210 of the YTZ-12. The YTZ12 and YTZ14 are basically the same battery being that 20 Cranking amps and .2 amp hours really aren't of any benefit and they are the exact same size.
Last, our battery is 360 cranking amps and has12Ah (PbEq rating) and will be much more powerful than even the YTZ14, and start the bike more times in a row with higher voltage and faster motor spin... BUT the YTZ14 Lead/Acid would actually last longer sitting in a garage with a mild parasitc drain using the batteries energy.... This is because the lithium battery has much more front loaded power in a smaller package and the lead is a denser brick that can hold more capacity... but that capacity is not effective at high amp draws like starting... So that is the trade off.
If you have any other questions let me know. Best is to email scott@antigravitybatteries... some time I don't get notifications from this thread.