A question for the clever types

[CBX1000chris]

Hi all,
A question regarding Lithium motorcycle batteries.

As far as I can tell Lithium motorcycle battery manufacturers would have you buy a Lithium battery specific charger and recommend against using a 'standard' charger, say an Optimate. If you put a lithium battery on a bike that was delivered with a 'typical' motorcycle battery, let's say a YTX9BS, won't the charging circuit be designed for the YTX9BS and not for a lithium battery?

I don't know what is different about lithium batteries that requires a different type of charging but when fitted to the bike that was supplied with a YTX9BS, as far as I know, it will be supplied with 13.5 - 14.5 volts without any form of 'special' charging arrangement.

So, is the need for a lithium battery specific charger a red herring or is it bad practice to fit a lithium battery to any bike that wasn't fitted with a lithium battery by the OEM?

Incidentally, I have a lithium battery on a 1968 Triumph (not fitted by me) and it has been ok for 5 years. I suppose it could be about to burst into flames though.....

Thanks for any replies in advance,
Chris.

[EMS]

A bike that comes from the factory with something different than a regular lead-acid battery, such as a Gel- or Lithium-Iron-Phosphate battery comes equipped with a regulator that accommodates the special needs of that battery type. My BMW K1600GT, for example. You can run a conventional batteries in these bikes with no issues. If you have an out-of-the-bike charger, that does not have a regulator and the charging performance may fall short of that needed for a Gel or a LiFe. I use a special charger for the battery in my K1600GT.
What the shortfall of the regular charging system IN the bike is concerned, when you put a Gel of LiFe battery in it, if it came with a conventional lead-acid, I don't know. I have not done that. You may not have a problem for a long time and it may bite you suddenly at one point.
I have not found it worth it, for any of my bikes to use an expensive Lithium instead of an AGM.

[CBX-tras]

I often wonder, how does the '70's era, CBX charging system, recognize the difference between a lead acid battery and a lithium-ion battery and charge it accordingly?

I'm with you, the AGM batteries work and last just fine. The expense and needs of the L-I aren't worth the trouble.

[Rick Pope]

I've been told that a charger with a de-sulfating function will quickly kill a lithium-ion battery. Of course, our bikes don't have that function, but the Optimate mentioned above may.

[Larry Zimmer]

Two comments: 1) Lithium isn't worth it unless you are racing 2) I believe the 'thing' about lithium batteries is that they are not tolerant (might turn pyrotechnic!) if the charging voltage exceeds about 14.5. Target max is 13.8 . While a lead acid system tries to regulate at about or below this point, a few might exceed it. Same goes for remote chargers. (Some cheap trickle things will go 16 ish or even 17. Don't want a Ford truck shipping yard adventure or GM Chevy Volt show.

[Rick Pope]

What Larry said. We have about $4,000 in batteries in our rv, lithium of course. Our inverter/charger is set to charge at 14.4v. In our case, the advantage is 8 times the available energy before needing a charge, and about 250# weight savings, plus they should last about 3 times as long.

[CBX1000chris]

Thanks everyone, the de-sulphate facility on a Optimate charger seems to be the issue. I copied this from Optimate:

Desulphation and recovery stage: Tests the battery for possible deep discharge or sulphation. If necessary, OptiMate 3 automatically engages a special high voltage recovery mode (up to 20V) with a very low fixed current to desulphate the battery.

If Li batteries don't like high volts then there's the issue.

On an entirely unrelated matter, is anyone else in the UK fed up of being cold? Maybe I've just got old but this winter seems to have dragged on, and on, and on.....

[EMS]

Don't you have to specifically activate the de-sulfation process? And if you don't, there should not be an issue. Why would you anyway with a Li battery?

[Rick Pope]

My Optimate "searches" for sign of sulfation and activates itself. No switch involved.

[CBX1000chris]

My Optimate de-sulphates automatically too so I would never be sure how it would behave with a Li battery connected. What the Optimate senses when a Li battery is connected is anybody's guess. Actually, it doesn't need to be a guess does it, I'll ping a message off to Optimate and ask them. Why didn't I think of that in the first place?

[CBX1000chris]

Some interesting articles on the subject but this one is pretty good. (It took me a moment to realise SLA = Sealed Lead Acid).

https://www.power-sonic.com/blog/can-i- ... a-charger/

Time to order a Li charger I think, my other half has bought herself a new bike with a Li battery fitted as standard. It's about as different to a CBX as a bike could be!

Thanks all,
Chris.

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[steve murdoch icoa #5322]

That Flat Tracker is a cool bike, Chris.
Watched a number of videos about the CCM line and the development of the Husky motor. Bet it would be a blast to ride.