Yet another DUD battery ,, !!!

[jerry]

What is wrong with modern AGM motorcycle batteries , I gave up on Motobatts as they were so unreliable 3 in one year 2 were changed under warranty in Thailand , replaced with a Yuasa ?????, Then 2 Yuasas in less than 2 Years in UK ,, Now a Unibatt in UK only 18 months has died its showing 12.8v but 2 cells are down when a load goes on ,, I am trying a French/belgian Made Fullbat this time ,,,

In years past Yuasas and Motobatts used to last me 5 years at least ,,, None of the bike have charging problems ,and I use optimates as well.

Other people are telling me that they are having similar issues with very few bike batteries lasting more than 2 years even on brand new bikes .....

[Ron1000]

FWIW I use jmt / jmp batteries on all my bikes. My 1100evo has had one in for four-ish years and starts no bother.

A local parts shop I use doesn’t like jmp, said he’s had a few issues. But certainly that’s not my experience.

[Mr Gazza]

My Motobatt is now over 11 years old and still never been on a charger.
I might have to relent and give it a little trickle, as it's gone down to 11.7 volts after being off the bike for nearly a year.

I think you must be buying those fake batteries Jerry? Always buy from a reputable source.

For what it's worth I think optimates kill batteries.

[Ron1000]

Same as mr gazza here. I don’t trust optimates, never put my batteries on trickle charge.

The evo battery has never seen a conventional charger, my streety RS has once and that’s about it.

[Stinger101]

Well, to put in my twopenneth, I use Yuasa batteries bought from a reputable source and they seem to last 5, 6 or more years. I always have and probably always will leave all my bikes permanently on Optimates or C-Teck battery tenders to zero ill effects since the late 90's. Currently I own 3 999's from '03 to '05 which must have similar systems to older Monsters. They always start off the button when I run them 4 times a year or so. Standard cables, standard batteries. I'm happy this way as it seems my bikes are too!

[jerry]

Last battery was Yuasa in the M750 bought from wemoto ,,, lasted 17 months 2 dead cells when tested under load ,, New battery in today is Fulbat bought direct from Fulbat main agent UK

The 3 Motobatts were from main importer 2 died under warranty the other lasted 2 years

I always buy from reputable sources ,, and avoid Chinky copies .

[crawsue]

I fitted a YUASA to my Evo at the 15 k desmo service November 2018….bike has now done 32k mls and battery still cranking….I give it an overnight on the Optimate 4 before a run…..I expect it will need replacement next spring…..

[Darren69]

I have had 1 Motobatt that failed after a short time but the others I have have been fine so far. Have you checked the voltage when the bike is running because if the voltage reg is not working it can overcharge and kill the battery?

[jerry]

Always check output of REG /REC should be 14.3 v when bikes are running M750 , S4 , Z900 , Z650 all at that number 14.3v 750ss is always 13.9v but is the old 2 wire system ...

[jerry]

The most recent DUD battery was in the M750 the battery is only 17 months old Yuasa 16-A2 bike has been used regularly , and on an optimate ,, no overcharging ,, the only thing I can think might have caused issues is that it was the bike that was knocked off the trailer in France back in June ???

The Z900 was only 18 months old when its original Yuasa died .. bike is mint and in perfect order.

The S4 the 3 dud Motobatts one may have been down to a possible faulty Optimate ? but its been ok on my wife Honda rebel 500. the other 2 were manufacturing issues for certain and were changed under warranty ???

I was wrong about the Unibat That one made in Italy actually lasted 4 years in the 750ss it was a Yuasa that failed in the M750

[yellowfever]

This sounds annoying and expensive! I always go with Yuasa (most recently replaced an 10 y/o Yuasa battery last year as it was getting tired) and have found they are reliable and last ages. I regularly use an old accumate platinum trickle charger to no ill effects I can see (on the contrary keeps things nicely charged during periods of little use).

One thought: as you’ve checked the reg/recs and they all seem fine, could there be a fault with your battery trickle charger that is prematurely killing your batteries?

[jerry]

I have 2 optimates, a halfords one and a Clarke one all 4 are working at correct amperage when charging I put my fluke on and the amperages are OK as are the charging voltages