Lithium batteries, overcharging and fire.

utopia · 02-11-2016, 10:18 AM

Ok, I know there have been many discussions on the subject of lithium batteries.
I've been tempted by the light weight and small size and so, despite still having some uncertainty, I bit the bullet and have fitted Magneti Marelli Li.Fe PO4 batteries to both the monster (M750) and my 650 Dommie.
I remain somewhat nervous though, mainly about the prospect of them bursting into flames.
And then today, on the "other" forum, someone posted a pic of a burnt out KTM.
I have no details but a lithium battery was in the mix.

The other day I noticed that it says on the case of my batteries that the charge rate should not exceed 15V.
Now, that might not be a problem if your reg/rec is working correctly but we all know that these units are unreliable .. indeed mine has previously malfunctioned, boiled a lead/acid battery and burnt out the multiconnector to the alternator.
My new reg/rec is hard wired, but I'm still not totally confident that the system is failsafe.
And 15V doesn't sound like much of a safety margin.

In my earlier considerations of lithium batteries, it was pointed out that the newer Ducatis such as the Panigale are fitted with Lithium batteries from new.
However, I have no idea whether the charging circuit has been modified to suit, or if it is the same basic design as mine.
And therein lies my question.

In a similar vein, I find myself wondering if it is possible to fit a voltage limiting device which would operate in much the same way as a fuse does to limit current ?
This would not be a second voltage regulator, but a failsafe limiter which would "blow" in the event of exceeding the charge voltage, or have some other mode of operation to ensure 100% that high voltage charging was impossible.

You'll have to excuse my relative ignorance of electrickery here, I'm afraid.

As a secondary issue, I'm wondering if there would be any advantage in wiring the headlamp to be on all the time, to soak up some of the excess.
I have heard suggestions of it being wired directly from the battery in these cases, but that's all I know.
I can't help wondering if this has something to do with the circuitry on the Pani etc.

So, I confess my ignorance and humbly enquire of the forum experts.
I thank you.

02-11-2016, 10:18 AM	#1
utopia No turn left unstoned Join Date: Jun 2010 Location: leicester Bike: M750 Posts: 4,545	Lithium batteries, overcharging and fire. Ok, I know there have been many discussions on the subject of lithium batteries. I've been tempted by the light weight and small size and so, despite still having some uncertainty, I bit the bullet and have fitted Magneti Marelli Li.Fe PO4 batteries to both the monster (M750) and my 650 Dommie. I remain somewhat nervous though, mainly about the prospect of them bursting into flames. And then today, on the "other" forum, someone posted a pic of a burnt out KTM. I have no details but a lithium battery was in the mix. The other day I noticed that it says on the case of my batteries that the charge rate should not exceed 15V. Now, that might not be a problem if your reg/rec is working correctly but we all know that these units are unreliable .. indeed mine has previously malfunctioned, boiled a lead/acid battery and burnt out the multiconnector to the alternator. My new reg/rec is hard wired, but I'm still not totally confident that the system is failsafe. And 15V doesn't sound like much of a safety margin. In my earlier considerations of lithium batteries, it was pointed out that the newer Ducatis such as the Panigale are fitted with Lithium batteries from new. However, I have no idea whether the charging circuit has been modified to suit, or if it is the same basic design as mine. And therein lies my question. In a similar vein, I find myself wondering if it is possible to fit a voltage limiting device which would operate in much the same way as a fuse does to limit current ? This would not be a second voltage regulator, but a failsafe limiter which would "blow" in the event of exceeding the charge voltage, or have some other mode of operation to ensure 100% that high voltage charging was impossible. You'll have to excuse my relative ignorance of electrickery here, I'm afraid. As a secondary issue, I'm wondering if there would be any advantage in wiring the headlamp to be on all the time, to soak up some of the excess. I have heard suggestions of it being wired directly from the battery in these cases, but that's all I know. I can't help wondering if this has something to do with the circuitry on the Pani etc. So, I confess my ignorance and humbly enquire of the forum experts. I thank you.