Adventure Bike Rider Forum

Could anyone please help with advice on lithium batteries? I fitted a lithium in May with no problems worked as it should, put the bike away Friday evening as normal, Saturday morning key in nothing! No lights completely dead, checked connections, all clean and tight removed the battery tested the voltage which read 1.4v. Left the battery couple of days(not on charge, I don't have a lithium charger). Question? Why would it discharge so quickly, do I send the battery back and hope for an exchange? Any advice appreciated

Sorry, left battery for a couple of days, voltage read 5.75v

What bike is it?
Have you recently installed any new electrical accessories?

Bmw G650gs Sertao, no extras fitted.
Thanks for reply

At that voltage I'm afraid its fecked, no idea why, have you checked for any parasitic current on your bike?
I.E., with a charged battery in place and the key out, dissconect one of the battery leads and place your meter set to measure milliamps between the terminal and dissconected lead and see if it shows anything

Hi, I do not know about the Sertao, but most modern vehicles have a constant small drain on the battery even when turned off. This normally isn’t an issue unless you leave them for a couple of weeks or more. If the lithium battery is smaller than the original this may be your problem. Either disconnect the battery every time you leave the bike or fit an isolator switch. It could of course just be a duff battery.
Cheers Jak

If it's been working as normal and then suddenly gone flat overnight with no changes to the bike then it's very likely the battery has failed, you didn't say what make it was.

Steve

The battery is a JMT,

Lithium batteries often need “warming up”. There are lots of posts re this in CCM GP450 circles.

The battery can sometimes appear dead. Putting it under load can revive it either by using the starter or lights.

According to Skyrich (as used in CCMs) as long as the charger can satisfy certain conditions it doesn’t have to be a dedicated one. The prime problem with not using a dedicated charger is the voltage range and and any desulphate process that is a strict no no.

See:

https://skyrichbatteries.co.uk/charging/

As an aside....
Dedicated lithium chargers won’t work unless they detect a battery voltage above a certain level. This causes problems when attempting to charge a flat lithium battery. You can fool the charger however by connecting a normal little 9v portable radio battery between the terminals, the charger will then detect this voltage and start charging the Li battery. You then disconnect the 9v battery.

There is some further similar advice re charging JMT batteries here:

https://www.motorworks.co.uk/vlive/Shop ... 5_90_RN_40

Tom

Greetings,

I have always been happy with Optimate battery chargers;

https://www.optimate.co.uk/information/

They make a special charger for lithium batteries.

You might need to check what type of battery is actually recommended by BMW for your exact model as it needs to match the charging system. Switching 'extra' lights or heated grips off can cause a sudden charge surge sufficient to damage the lithium battery.

TTFN

Hugh.