Motobatt/ charger question.

[oldie54]

Hi all, having contacted Motobatt and Oxford products and received no replies let's see if here is a more helpful place. I have an Oxford oximiser 900 charger but my battery is still struggling to start once I have been out riding and started it a couple of times. I read that Motobatt make a great battery and people rate them. I need to know if my charger will be compatible with this type of AGM battery and google searches have left me flummoxed. Any opinions out there?

[Mr Gazza]

I can recommend the Motobatt wholeheartedly, but as for a charger i couldn't say as it has NEVER been on a charger in the three years it's been on the bike.

If it ever did need a charge I would just put it on my old fasioned charger...Probably not the answer you are looking for if you need to keep topped up for an alarm?

The other thing to make sure of is that the heavy leads from the battery to earth and to the starter, have really good clean connections.

[Dukedesmo]

I have Motobatts on both my Ducatis. As above very good and never actually needed topping up however I have topped them up just to be sure it was 100%, using both Ctek and Optimate chargers.

Despite the AGM construction they are still basically a lead acid battery and not some fancy/finicky Lithium jobbie...

[oldie54]

That sounds fine then, Motobatt it is. All I have to do now is find the battery.

[utopia]

Just a thought ....
You say it struggles to start after you've been riding for a while but I would have expected it to be recharching adequately from the alternator during use.
Is it worth getting the charging system checked over ?

[oldie54]

Hi Utopia, very possibly a good idea but I have the battery in an oximiser all the time and I would expect a good battery to manage more than a couple of starts before giving up. The only way I started it last time this happened was to press the starter repeatedly before the R2D2 nonsense had finished as this was what we had to do with my better halfs Daytona when , funnily enough, we found the shop selling it had put in the cheapest battery they could find. I am going to try a new battery as this seems the cheapest route first, if that don't work then I will have to look harder.

[Flip]

Hi Utopia, very possibly a good idea but I have the battery in an oximiser all the time and I would expect a good battery to manage more than a couple of starts before giving up. I am going to try a new battery as this seems the cheapest route first, if that don't work then I will have to look harder.

Surely the cheapest route would be to stick a multimeter across the +ve and -ve terminals while the motor is running to determine that it actually being charged before spending out on a new battery (assuming the battery fitted is of the correct capacity of course)?

[oldie54]

I don't know how to use a multimeter and to be honest the last time I tried to get to the battery I failed. I have never owned a bike which didn't have the battery under the seat. I will see if I can find a YouTube video on checking a charging system with a multimeter.

[utopia]

Electrics aren't my best subject either but in the past I have used this flow chart to guide me through the process.

https://www.electrosport.com/media/pdf/fault-finding-diagram.pdf

And here's a thread which describes the same testing process in a different way.

http://www.ukmonster.co.uk/monster/showthread.php?t=46708&highlight=shindengen

To do a basic check on the charging voltage you just connect the meter (in voltmeter mode) across the battery terminals, without disconnecting anything, then start the engine and observe the charge voltage at tickover and at higher revs.
Another basic check, to identify any current drain, would be to disconnect the battery negative lead and reconnect with the meter in ammeter mode between the battery terminal and the negative lead.
This will then show if any current is flowing when it shouldn't be (ie with everything switched off).
Alarms need to be taken into account though.

[Darren69]

I don't know how to use a multimeter and to be honest the last time I tried to get to the battery I failed. I have never owned a bike which didn't have the battery under the seat. I will see if I can find a YouTube video on checking a charging system with a multimeter.

If you've got a charge lead fitted that connects directly to the battery you can connect your multi meter to that, but I think some types charging leads are connected through the diagnostic port in which case that probably wouldn't work.

[oldie54]

Cheers guys, I will give that a go as I have a charging lead attached to the battery.

[oldie54]

So , I have had a go. Battery shows 12.8v with bike not running. Bike then refuses to start having been on an oxford charger for a few days. Plug charger back in and fire up bike with it plugged in, bike starts and reads 13.8v whilst idling. Charger reads 13v when plugged in and is doing a bulk charge not the maintainance which it normally reads. BAttery at all stages sounds like it is struggling to turn the bike over. Any thoughts folks?

[DrD]

Sounds like a battery with one or more poor cells - appears to charge but the CCA rating has dropped.
If taht is 13.8V running at idle with the charger disconnected that sounds ok.
You also need to check with it at about 2500/3000 rpm, again with the charger disconnected.

[Darren69]

Yea you don't want to see anything much above 13.8 - 14.0 v when you rev it otherwise its overcharging (not regulating) which will also kill the battery.

[oldie54]

New battery it is then. Cheers everyone for your help.

[oldie54]

Final update on this thread I hope. Motobatt arrived yesterday, fitted along with a good deal of cursing. Result, bike fired at the first push of the button.
Italian bike day here I come.

[Dukedesmo]

Other than being heavy, they're the best choice.

My 916 used to have to live on an Optimate as more than a week and the Yuasa battery didn't have the guts to start it - it would turn over but there wouldn't be enough voltage to power the ignition/injection.

I've only ever had a Motobatt on the Monster and it starts first push, despite having the older (harder to start) ratio on the starter gear and high compression pistons.

My Guzzi LeMans had a huge 30ah battery but was a pig to start and whilst pushing the starter, battery voltage would drop to 4-5v. I fitted a 32ah Motobatt and it spins so much faster now with voltage only dropping to 10v on cranking - it does weigh over 10kg though :eek: which is about 2kg more than the old lead-acid battery but as it's a very heavy bike I'm not too concerned about weight reduction. And I'd rather have a bike that starts every time than push a slightly lighter one...

[utopia]

30ah !!!
10 kg !!!!!!
Blimey.
I thought the 16AL-A2 battery on the monster was heavy at over 6kg, but that's on another level entirely.
I've just replaced it with a Magneti Marelli lithium one .... weighing in at an ethereal 800g.
Its an unknown quantity to me as yet so I didn't think I could really recommend it ....motobatt is a more appropriate, proven choice in this context perhaps.

[Dukedesmo]

30ah !!!
10 kg !!!!!!
Blimey.


Indeed, Guzzis (at least the old ones) have a car-style starter motor that engages directly onto the flywheel and as such they need a lot of power to spin it fast enough to start.

It's basically a (not so) small car battery... :eek: