Trouble is the TN110 measures L355 x W176 x H189mm which I reckon is a just a good under seat fit. (I could be wrong as I’m basing this on CAD drawings)
Yep, might just squeeze under but you might need to lie it on its side if it’s a swivel seat. Roamer 100Ah is 325 x 170 x 220 (£450) so that’s same issue but we designed a 200Ah that fits perfectly under a T6 seatbase measuring 290 x 330 x 180 - terminals are on the side so you can access these without snagging cables. At £855 it’s not much more than the 110Ah TN battery, has higher charging and discharging rates, Bluetooth monitoring and low temp charge protection