I tried jump starting it with my sprinter van engine off, and on. Just heard a click. Tried leaving it to charge a little longer, then when I tried it, I got the DESS Error and orange screen.
One thing I'm terrified of, when I checked the dipstick, it was very low on oil. Not sure where the oil would go with it sitting.
When you check the oil level on these things, it
MUST be done within minutes of shutting down the engine after running/ryding it for some while. This is because after you've shut it down (& checked to oil level

) the oil will drain out of the dry sump reservoir over time as it sits, leaving you with what
looks like no or low oil; but unless there's a large puddle of oil under the Spyder, then it
IS NOT a low oil level; so if you have oil
just showing on the bottom of the dipstick after it's been sitting for a long while, then you
KNOW it's got oil in there & unless that puddle is on the ground underneath, then it's just not in the dry sump reservoir where the dip stick is, so it's almost certainly got very close to having the right quantity of oil in there!
DO NOT ADD OIL when the level is showing on the bottom of the dipstick like that after it's been sitting for more than an hour or more or you risk over-filling it and if you try to start run it after adding more oil/over filling it, you may well end up damaging some expensive & difficult to repair things! :yikes:
So don't panic, from what you've told us, the oil is probably at the correct level - or close to it! But you tell us it is at least a couple of years old, so if you're really concerned, maybe you should just drain it all without trying to run it beforehand (cos it'll be cold oil & not necessarily in the 'easy to drain' spots, leave it draining over night! :lecturef_smilie: ) change the filters, and refill it with the correct quantity of oil for that particular model - being careful
NOT to over-fill it! :thumbup:
As for leaving a
really dead battery connected only by jumper leads to another vehicle battery while the engine isn't running for any extended period, you're really only likely to end up with 2 dead batteries as the charge between the 2 equalises - a fully charged battery draining into a dead battery with zero charge = 2 flat batteries, if not 2 dead batteries! Even if you leave them connected while the other vehicle's engine
IS running so it's alternator can charge it too (& risk damaging one or both vehicle's computers by doing so!

) it'd still take many hours to recharge a dead flat battery that way - well,
IF the Spyder battery hasn't died completely/shorted internally & it could even be done!

So you need to either leave the Spyder battery charging on a proper charger (not just a battery tender :sour: ) for at least 12 hours or so, altho that dead battery might be well & truly knackered & never take a charge again; leaving you with the better option likely being to be getting a new battery, putting it on a charger for at least 12 hour or so, then fitting it and only then trying to start your Spyder!

hyea:
Good Luck! :cheers: