Bike Electrics Brain Teaser

So heres my problem:

I keep my bike in a garage that has no electicity supply.

If I don’t ride the bike it takes about 8 or 9 days for the battery to run flat. Slightly less if I put the alarm in “winter mode”.

So at the moment I have to keep taking out the battery, bringing it upstairs and sticking it on the optimate. Fine. But a complete pain in the *rrse!

Now a mate has kindly offered me a great big truck battery. He says I should keep it next to the bike and just hook it up in paralell to the bike battery, so that both batteries equalise and run down together - giving a garage life of a month or longer. Then from time to time I just take the truck battery upstairs for charging.

Seems like a great idea, but I’m a bit worried cos electrical stuff is some kind of black art that I have no understanding of. Is this a good idea, or do I risk introducing gremlins into my bike? I know alarms can be a bit on the sensitive side. My mate who offered the battery seems to know his stuff as he works with generators and stuff, but always open to hear other people’s ideas.

Any takers?

Sounds like a good idea to me. I recently shagged my battery and wasn’t able to get hold of another one for a bit. I had another spare different sized battery so I hooked up some leads to the second one in parallel to the first and for a week I was riding around with one duff and the second. It should work fine. The battery supplier said the one thing that will kill a bike battery is to let it run completely dead as you can’t recharge it afterwards even with an optimate.

I would get a new battery

i thought some trucks were 24v?

They are…2 X 12V batteries though.

Thanks all.

This is a 12v truck battery. But its massive. I recon Im going to need a trolley to get it up to the flat when I need to charge it. And apparently it takes about 3 days on the optimate.

Vale- do you recon my battery is shagged? I thought about 10 days was normal if you have an alarm on the bike?

If your only getting 10 days, either the battery is on it’s last legs or the alarm is crap.

+1

In a similar scenario 10+ ago I used to be able to leave my zx-6r with a Datatool Veto alarm for at least 3 weeks without needing a re-charge, newer alarm technology should be a lot less draining on batteries.

Does the garage have any windows or translucent roof panels ? If so you could maybe try using a solar trickle charger when not in use e.g. :

http://www.getgeared.co.uk/OXFORD-Weatherproof-Solar-Charger

That’s a good, straight forward idea. Nice one.

I’ve not checked but I’m willing to bet that Maplins sell at least one version.

(Doesn’t need a window. Depending on the location/vandalism, just needs to be outside and vaguely pointing South.)

solar chargers are not very good, it would likely be better to disconnect your normal battery and connect it to the truck battery…otherwise the bigger truck battery will force current through the smaller battery and damage it…or so the story goes, there are people who say this is not true…but I would play safe with two batteries of such different potential…

I have bought the solar chargers from Maplins (when in the sale) and they do keep a battery in good condition for ages. I have a battery from my XJ900F that has been on a solar charger for over a year and it is always in good condition.

I have some of my bikes set up with a cigarette lighter socket to plug the solar charger into and it stops the batteries dying.

And they are unaffected by rain

Your battery is not feeling well , the parrallel arrangement will in effect continually re-charge your battery from the truck battery so that current will flow continually …why punish your ailing battery ?
Get a new one or at least do as 2 st says and take your battery off .
The batteries are actually of the same potential difference but can deliver a very different curent duty…SO IN SHORT…GET A NEW BATTERY .

Your battery is not feeling well , the parrallel arrangement will in effect continually re-charge your battery from the truck battery so that current will flow continually …why punish your ailing battery ?
Get a new one or at least do as 2 st says and take your battery off .
The batteries are actually of the same potential difference but can deliver a very different curent duty…SO IN SHORT…GET A NEW BATTERY .

Thanks for the advice. Something told me that this might not be a straight forward as my mate was telling me. Maybe the fact that his own battery is fried and bike is grounded…:w00t:

I guess I need a new battery. Unfortunately its an underground garage so solar wont work for me unless I rig up miles of cable.