Home of the battery.

Turns out that what I thought was a problem with the flasher unit in my PX was ultimately a simple case of a flat battery. After putting the battery on trickle charge overnight using my Battery Tender everything fired back into life again this morning.

The indicator light on the Battery Tender however still showed red for charging after being on all night for close to 12 hours so the battery must have been reaaaally low. I’m going to put it back on again tonight until I can get it fully charged.

Given that the battery ran flat after just two weeks of normal riding since I took it off the tender from winter storage, there are two potential culprits:

1. The battery is old, and just won’t hold a decent charge for very long. Very possible. I bought the scooter used, and have no idea how old the battery is.
2. There’s a problem with the rectifier/regulator, which is a small device behind the battery that is responsible in part for keeping the battery trickle charged during engine operation. Apparently while these units are some of the more complex electrical components in a Vespa, they are also among the least likely candidates to fail. Assessment? Unlikely a problem here.

I’m only just becoming familiar with motorcycle/scooter batteries and made the common mistake of assuming that they work the same way as in a car. They don’t.

It turns out that during normal riding operation, the scoot will charge the battery but can only pull enough charge to keep the battery roughly topped up. What it can’t do is merrily charge the battery above and beyond its current charge. In short, with a flat battery on a car, after a jump-start, and leaving it running for a few minutes, you can gradually charge the battery back up to full after a good drive. Not so with a scooter battery.

One thing for sure, I’ll need to keep an eye on the battery over the next couple of weeks. If it fails again within a month then I’ll start by purchasing a new battery and hopefully that’ll fix the problem. If not, my attention will turn to the rectifier/regulator.

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