JMT GEL battery - YTZ14S 12 Volt - Honda XL 700 V Transalp 08 [incl. € 7.50 Battery pledge]
This battery is about 50% cheaper than the original, but does its job quite well so far. I think they will keep / work a few years. The original has lent 7 years without problems at 100% of their power.
