Trickle Charging from Leisure Battery

[KickStarter]

Hi All!

So, I have a garage away from home, that I leave one bike at a time in, the other is the one I'm using at the time. (XSR700 / F800GS or the 1996 600TT)

The XSR and GS, have trackers, and therefore flatten their battery fairly quickly.

There is no power in the garage for the trickle charger, and whilst I could look into putting a solar panel on the roof of the garage, the roof is asbestos so I'd rather not interfere, and secondly it would alert passers by that there is something of interest in there.

I do however have a very large leisure battery inside something like this (Picture below)

I am therefore looking for a means to trickle charge, from a 12v battery.

This far the best I can seem to find is something like this:

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Suggestions welcome!!

Thank you

 

[SBD]

You’re going to struggle with that, as the big battery will only have a few more millivolts than the bike battery until the bike battery is somewhat discharged - chargers are normally working from a higher voltage source and current limited.

And anything active will waste energy as heat, though you could run a charger off an inverter. Doesn’t seem like a good plan.
I suspect if you simply connect the big battery in parallel with the bike battery, it’ll do what you want as your tracker etc would have to run down both which will obviously take a long time.

You can then take the big battery for a recharge eg once a month and the bike will be ok overnight or whatever until you reconnect them

 

[Chalky723]

Get a different tracker? Monimoto lasts a year on its own batteries.....

D

 

[DevonAl]

If the solar panel is flat on the roof and fixed with CT1/Sikaflex it should be fairly unobtrusive and run the cable in through door/window frame?

Al.

 

[wessie]

What SBD says. Fit a fly lead to each battery and have a lead from the battery that plugs into the fly lead on the bike. If you match the connectors to your home charger then the fly lead can be dual purpose.

 

[KickStarter]

Thanks @wessie and @SBD

I somehow had in my mine, wiring them all together was a bad idea..

So literally battery terminals through to the charging lead on the bike, just with a fuse for good measure...

@Chalky723 looks cool, but the tracker has proved great otherwise, and I pay annually haha

 

[cookie]

You should use big cables if you connect up the batteries in parallel as suggested. If the bike battery fails, the big one will dump into it at a high rate and frazzle little charger spec cables.
I personally wouldn't leave them connected like that at all.

 

[KickStarter]

Hmmmm yeah I really don't want to start a fire....

 

[wessie]

You should use big cables if you connect up the batteries in parallel as suggested. If the bike battery fails, the big one will dump into it at a high rate and frazzle little charger spec cables.
I personally wouldn't leave them connected like that at all.

a fuse would stop that surely?

 

[er-minio]

If you are trickle charging one bike you can do it with the 20W panel kit from Optimate. The 20W panel is fairly small, the cable is extremely thin and it's easy to fix the panel and run the wire across the ceiling.

 

[Bem]

a fuse would stop that surely?

I would put a low amp fuse eg 3A in both lines on the big battery side, just before the flylead.
Others may now make known different views.

 

[wessie]

I would put a low amp fuse eg 3A in both lines on the big battery side, just before the flylead.
Others may now make known different views.

probably the best idea - the fly lead might be used for higher rated stuff such as a tyre compressor so if that lead is fused it would need to be large enough for any appliance connected.

 

[Strongbow92]

With two batteries connected in parallel the one with more charge will feed the other until the voltages match. The higher the voltage difference between the batteries the more current will flow but as most 12V batteries have a small voltage change between full and flat this will probably not be a problem. As said before a fuse is a must as a short in one battery will deffo lead to stuff melting. You could use a current meter to work out how long the big battery will last.