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D15NEL View Drop Down
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    Posted: 08 Feb 2026 at 10:56
Morning all

I have a 2004 Triumph Thruxton which is fitted with an AGM battery.

What's the consensus of opinion on battery maintenance during any lay up period? 

I have an Oxford Oximiser 600 battery maintainer wall mounted next to the bike which I plug in for 24 hours and then disconnect every couple of weeks but would I be better just leaving it plugged in so that it can cycle through by itself?

I started the bike last week after a few weeks lay up and had to use my son's NOCO power pack as the bike wouldn't fire from the battery. I then took it on a 50 mile, cold but enjoyable blast! Battery was a couple of years old so as a precaution I have fitted a new Yuasa battery rather than get caught out.

Does leaving the maintainer connected damage the battery in any way?

Be grateful for your input.

Many thanks David 
David
Retford, Notts.
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Brian UK View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 08 Feb 2026 at 13:27
No, don't leave it connected permanently.
But, a battery maintainer isn't going to fully charge the battery, or at least many don't.

A better bet, in my opinion, is to use a smart charger which will fully charge the battery, every few weeks.
Also, having just checked the spec of your Oxymiser, it charges at 600mA.
When I bought an Oddessy AGM battery, it clearly said on the instructions - minimum charge rate 2A. So your 0.6A charge rate is not enough.

Try charging your old battery with a different charger, then see how it performs, it may just be that it's not fully charged. A qquality battery should last more than 2 years, though manufacturers are fitting smaller capacity batteries these days, which doesn't help.
Brian.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Moto Gazza Quote  Post ReplyReply Direct Link To This Post Posted: 08 Feb 2026 at 14:56
By chance I have just pulled this out to put up for sale as I never use these things, rather I use my bikes..
It's an Optimate 111.
I've tested it on a spare battery just this morning.
The battery was sitting at 12.2 volts and after a minute connected, the optimate rose to 13volts and was still slowly rising.
I only clipped it on for the purpose of a test and to take a photo, so it was only on for a couple of minutes, but it left the battery at 12.7volts.

Includes 3 different optimate leads, but no instructions.. Sorry. Seems to be plug and play to me anyway.

£15 +P&P if it's any good to anyone?..Optimate now sold.. Thanks.






Optimate now sold.. Thanks.

Edited by Moto Gazza - 09 Feb 2026 at 19:36
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 08 Feb 2026 at 21:09
That delivers the same charge current as the Oximiser.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote AdrianW Quote  Post ReplyReply Direct Link To This Post Posted: 09 Feb 2026 at 08:32
I have an Oxford Oximiser somewhere, came free with a magazine subscription years ago. Must admit it's still kept in its box "just in case"!
Each Winter I remove the batteries from all my bikes and sneak them into the house out of the cold..
I charge them once a month with the trusty Optimate III SP ( the 6v ones with a small Hein Gericke auto charger). I have noticed that the Optimate doesn't fully charge the 12v ones, I top them up with my ancient Gunsons motorcycle charger or the Hein Gericke.
These are a variety of battery types, AGM, lead acid, sealed alarm, Cyclon etc.

Maybe these new "smart" chargers are ok to leave on permanently but I never fancy the idea. I definitely would not with the older type whatever they claim. Besides with 6 bikes having one for each would be a tad expensive..... !!

I agree it's worth taking the suspect battery off and trying a top up with a basic auto charger. If it's a Motobatt it might simply be on the way out. I find they have a habit of expiring suddenly so don't buy them any more....

Hope this helps,
Adrian
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Brian UK View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 09 Feb 2026 at 13:47
I wouldn't leave any charger permanently connected to a battery no matter how smart it was claimed to be.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote paulbricey Quote  Post ReplyReply Direct Link To This Post Posted: 09 Feb 2026 at 16:22
I DO leave all my batteries (NOT Li & on their bikes plus one justing sitting on bench) pretty much permanently connected to Optimate 6 (Smart maintenance apparently) and similar but less Smart other ones. I've never had any issues & amazingly the Yuasa that used to be on my Griso & now relegated to V65 is still going strong at over 12+ years. 

Occasionally I connect my BMW X3 up to the Optimate 6 for a couple of weeks at a time because the big 'start-stop' batteries in the boot tend to go low enough to trigger a 'charge your batteries' message (despite I hate Stop-Start and try to remember to switch it off whenever starting engine - another waste-of-time tech that seems to always STOP the engine just as you want to move forward.


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Post Options Post Options   Thanks (0) Thanks(0)   Quote Mike H Quote  Post ReplyReply Direct Link To This Post Posted: 09 Feb 2026 at 20:18
Originally posted by D15NEL D15NEL wrote:

I have an Oxford Oximiser 600 battery maintainer wall mounted next to the bike which I plug in for 24 hours and then disconnect every couple of weeks but would I be better just leaving it plugged in so that it can cycle through by itself?

For what it's worth, I do this using an Optimate, for two bikes and the car (if not recently been used). Every two weeks, and I learned that when it shows two green LED's that doesn't mean it's finished, it just means it's gone into monitor mode where it's still charging, but in on/off cycles. Usually stays connected for at least 24 hours, the car usually needs 48 hours or maybe more. I've been doing it this way for a few years now with no issues. 

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Throwley Quote  Post ReplyReply Direct Link To This Post Posted: 10 Feb 2026 at 08:36
I left my Oxford Oximiser hooked up to my new battery over winter a few years back.  Came to start it in spring and the battery was discharged fully and was irrecoverable. I assume the Oximiser had failed and dragged the battery down with it somehow.  Even using the parallel-charge trick with a healthy battery couldn't bring the battery back. Both battery and Oximiser went in the bin, I now use an Optimate connected for a maximum of a week to maintain my battery.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 10 Feb 2026 at 10:37
I use my trusty CTEK charger.
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D15NEL View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote D15NEL Quote  Post ReplyReply Direct Link To This Post Posted: 11 Feb 2026 at 10:10
Thanks for all the responses.

The consensus appears to be that I shouldn't leave the Oximiser permanently connected but carry on as I have been and connect it periodically for 24hours to top up the battery. This unit has normally charged my batteries and the instructions do confirm that it's not a fast charger but only delivers a low rate for a slow charge and then a maintenance trickle. I am wary of leaving it connected permanently as I have heard stories of these types of unit drying out the battery or similar.

After my starting issues the other week I may have jumped the gun buying a replacement battery as the old one I recharged is holding a steady level of charge at 12.8V. The bike does take some starting after a few weeks of inactivity but the Noco power pack is a compact and useful back up if needed.

I do agree that the best method of charging is to use the bike which I normally would do but I had a couple of tyres fitted just before Christmas and the front needed a retrue on the spokes which I was able to get sorted locally. I took the opportunity to refurbish a few bits whilst the wheel was out and have just got it back together. The weather isn't helping at the moment as it's still raining so tend to use my pushbike instead.

At least I have a spare battery now too!

Thanks again for the advice.




David
Retford, Notts.
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