Modern Vespa

Hello

I bought a used 300 hpe sport here in London, UK
the previous owner hadn't had much use of it, and had it on a trickle charger.
It rode fine back home and again on another trip of c 2 miles.

I didnt ride for a week after, and the bike wouldn't start - dashboard showed c 10 volts.

I disconnected and charged up the battery, and the bike started fine. I checked the voltage at the terminals (with a multimeter) when running was c 14.5v which i presume means the stator works as well.

I left the bike for a couple days, and now it refuses to start again; 10.5 v on the dashboard.

Now, I presume I need a new battery. The one in the machine is YTZ14BS. The manual doesn't say a specific model, but its got a diagram with a yTX12BS in the picture. There is a specs table at the end that only says 12v with 10Ah.

So ... what battery do I need?
Also, I am just a bit concerned about parasitic leakage. Is there anything specific i should look at before ordering a battery?

thanks!

YTX14-BS OR YTX16-BS. Either will do.

ytx-14bs arrived ... but its about an inch taller than my old one!

got to see if it fits....

For what it's worth ..

The YTX14-BS is too tall to fit in the battery compartment. You cannot close the screw on 'lid'.

You can place the lid over the battery , but need longer screws, and it is no longer fully sealed. The seat does close, so there's that.

Will try to return the battery, else its an expensive lesson to check specs carefully

Is there no underneath battery tray that you can remove?

Unfortunately, there is no tray underneath.
I am returning the YTX for a Motobatt equivalent of the YTZ

Good luck with that. None of my Motobatts (I tried three) lasted more than a year. After six months of use they all began to self-discharge, eventually not holding enough charge to start after two weeks of standing. Pretty poor for an AGM design.

That all mine suffered in the same way may just be coincidence of course, and perhaps someone daily driving just one scooter wouldn't experience anything like that.

and I have had just the other experience with motobatt. I don't charge them . let them sit all winter long , might have to put an hour charge on them and fire up the scooters and good to go. buy new ones every 3 years or later.

Which model did you go for? This one? https://www.thebatteryshop.co.uk/mbtx12u-motobatt-agm-motorcycle-battery-12v-14ah-200cca---yb12bb2-ytx12bs-ytx14bs-ytx14hbs--15410-p.asp

Also, do you need a special kind of screwdriver to disconnect the terminals? I've tried a Phillips and a flathead with no success.

And yes, my old battery has only lasted 8 months! At least I hope it is the battery!

battery bolts are just a large philips unless they have been changed, because if you add on a pigtail for the battery, you might need longer bolts to catch the nut, I did on my hpe 500

Thanks - they're just done extra tight. Really annoying!

It doesn't hurt to use a drop of blue loctite on the threads to prevent them from loosening up due to vibration.

I always use a socket vs. a screwdriver since the screws tend to distord pretty easily.

Totally agree with sbaert, also be careful to not overtighten, the poles on batteries are like butter and snap quite easily, far better just snugged down with a bit of blue