Battery advise please

[Messie]

I'm a bit of a thicky when it comes to mechanical things, specially when it's electrical. So I thought I'd ask the collective wisdom of .org even tho it's not an SV

My RSVR Mille has a tendency to drain the battery when stood still for any length of time. I've disconected the alarm but it's still a problem if I leave it for more than a week.

Now I could get a new battery but I'd rather not if I can help it. I can't leave it connected to an Optimate or similar because there's no electricity at that end of the garden.

However I've been told that Maplins are doing a solar powered trickle feed for 12 V batteries for cars and boats.

Could I use this on the bike? I think it's a 12v because I've jumped it from the car before. What are the opinions from those more knowledgable than me?

[fizzwheel]

My brother has the same problem with his RSVR to. He's never got to the bottom of it. Same symtoms, bikes left stood for a while and it wont start.

He's checked the reg / rec and the charging circuit and all is well. He's just recently bought a new battery for it, but this time he's gone for an uprated battery. His thinking is that the battery is to weak when its down on charge and it tries couple of times to turn the bike over fails and then its flat.

I think he said he's bought a 14amp battery instead of a 12amp and that seems to be working out better for him.

It is a 12V battery, but I'm sure I've read about not using stuff thats designed for car batteries on bikes. But I cant remeber why.

I'm sure somebody with a little more knowledge than me will be along shortly.

[embee]

It'll be 12v so if you think the trickle charger will help then it should be fine.

Sounds to me like you need to determine for sure whether the problem is with the bike or the battery.

The best way is to measure the current drain from the battery when everything is switched off. I'm not sure what bikes will typically be, but based on car systems I'd say anything above single figure milliamps (mA) will be a problem. For example, 20mA drain over a week will cost you 20x168milliAmphours or nearly 3.5Ah. If your battery is mid-life it'll probably only hold a usable 8Ah or so, and therefore will be half discharged.

I'd really want to see less than 5mA discharge.

If it is as low as this and it still goes flat, then the battery itself might well be on its last legs.

The next step is to leave the battery disconnected for a week or so and then see if it has held enough charge to start OK.

Recommended batteries are the YTZ range from Yuasa (better than YTX types)
http://www.yuasabatteries.com/battery_search.asp
According to that the YTZ14 is the same length x width as the recommended YTX12, but is actually shorter so should fit no probs and will give 230Amps cold cranking current for starting compared to 180 from the YTX12 range.

or some recommend Westco AGM batteries which are similar technology.
http://westcobattery.com/battery_info.html

[Messie]

Thanks for the info guys - a little complicated but useful. I'm reassured that it's a commonish problem. Think I'll invest in a new battery rather than faf about with a solar trickle thing.

Where's a good place to but batteries then?

This is a common problem with the Litre Aprillia's and the recommended fix is to fit the 14 amp battery. My old man has a Falco and I'm sure he stuck the bigger battery in it after some advise to found on the Aprilia Riders Forum.
Any decent dealer should be able to get a battery for you.