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Gel are still Lead Acid. But a *** to rejuvenate if they get dry.
I hate sealed lead Acid batteries - ime - 80% plus of dying M/C batteries just need a bit of distilled water.

Here - For your entertainment - a quick note I drew up last week for a UK mate recently emigrated over to Spain.
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Okey Dokey Lead/acid vs "Lithium"

Some of this is theory and some experience.

It's all really down to chemistry. And how it allows electrons to be held (stored) and moved.
Batteries (all batteries) are rated by Cycle Discharge. This is governed by chemistry.
Forget the CCA thing - it's just a number. And it's sort of made up.

And first off let's clear up "Lithium". Lithium itself is only part of the chemistry, its a metal - There are various other ion-compounds that work with Lithium (Li), but some are better than others. The current undisputed king is Iron Phosphate (FePO4). It's safer and less prone to charging damage. The Li batteries used in phones etc have a chemistry that is actually more energy efficient - but far less stable and less long-lived.

A Lead acid "cell" can store at about 2.2V - Hence a "12V" battery has 6 cells in series - 13.2V.
A Good LiFePO4 cell holds 3.3V - hence 4 in series comes to 13.2V.
This is a very happy accident - with other Li chemistries it's not.

The amps available depends on the number of cells in parrallel and or their phiscal dimensions - Chemistry independant.

"Starter" rated batteries on modernish Internal Combustion vehicles have to deal with a couple of things.

1) Starting - This requires a pretty big surge of energy for a short time.
2) 24*7 component low power constant drain.
3) Less importantly - it stabilizes the alternator output. Most modern R/R's do this pretty well once the alternator is charging - but in traffic the circuit voltage could other wise be too low.

There are also "deep charge cycle" variants of Lithium and lead acid - Forget them.

Lithium Batteries can be thought of as "dry" though in fact they're not. But the tiny amount of liquid inside does not produce gas - so they don't need to vent.
Lead/Acids do need to vent - Sealed batteries are water tight but not air tight.

So what's the hype. Lithium metal is light. Lithium batteries have very little liquid. Lead is NOT light and acid by definition requires water to work.
And for a given amount of electrical storage (Joules of Energy) - LiFePO4 is lighter. But also more expensive.

But now the fun bit. LiFePO4 chemistry can discharge up to 3 times as fast as a lead acid. I said "CAN".

A good lead Acid is lucky if it has a short term 15 (discharge) Cycle rating - So a 20ampHour battery could just about discharge 300amps.
A good LiFePO4 has a 20 cycle rating with short term rating closer to 45. So a 7.5aH can pump out close to 360amps for a couple of seconds.
I have some early 8aH cells that are 70 Cycle rated - these are frankly dangerous - They would stop your heart.

The reality is that these numbers can be compromised by construction of the battery itself - including material purity.
But using less materials keeps the cost down - though still not as cheap as lead!. And may lead batteries are not PURE lead either.

If a starter is 1.2KW - it needs (on paper) 100amps at 12Volts. The reality is you cannot discharge a battery at 100% capacity however - there are other components like the ECU that simultaneously require a stable power supply. More in this in a bit. My R.O.T. - double it and add a bit. Triple to be safe.

Brilliant you say - let's stick in a 7.5aH. And if we were ONLY talking about starting a track bike, then fine. BUT we have that 24*7 drain to think on.
If you have something drawing (as an example 0.5 Amps - then a 20aH battery will last 40 hours approx before being drained. A 7.5aH will only last 15.
Lithium becomes a liability rather than a plus.

A plus for a good LiFePO4 is that its charge cycle rating is also high. So you can charge them up faster.

When discharging close to limit - Lithium based batteries tend to hold voltage and loose ability to flow amps. Lead Acid tend to flow amps and loose voltage. Depending on the vehicle itself, this can work either way. ECU's have a low voltage threshold. But tbh if the ECU says low volts it's not charged enough anyway.

Now an experienced based Downside.

Some are very sensitive to ambient temperature. This is an overall known problem with the chemistry, but some batteries are more prone to it than others.

If I leave my Lithium battery'd bike FULLY charged in (for example) my mum's garage overnight in UK spring. The battery will initially struggle. The trick is simply to cause some drain to the battery - i.e. lights - for a few seconds - then hit the starter. I had the same issue last weekend here. If the bike has lights that only come on when the bike has started - it matters!. The chemistry has to ramp up a bit.

This effect is FAR LESS prevalent in lead Acid batteries except at EXTREME COLD. Spitsbergen in Winter cold (when even Polar Bears hibernate)

Another Downside. Li batteries are NOT as resistant to over and under charging as Lead Acid.
Under charging will not be much of an issue real world as the ECU will have already stopped recognizing the battery - and you'd have had to recharge.
Over Voltage damage is possible and an over protected battery is strongly advised.

Lead Acids will boil dry if they overcharge. Be they liquid, AGM or Gel.

If it were me - I would fit a GOOD Lead Acid. YUASA is always a safe bet.

And buy a small jacket-pocket.sized Lithium Booster pack that you can keep inside - where you can occasionally check charge and it's warm. Stick it in your jacket when you walk down - and if you need it - it's there. I have a Noco booster pack (it's overkill sized though) and it keeps full charge for months.

Some have a harness you can leave attached to the bike battery so you don't have to (shock horror) lift the seat.

If you really want to go Lithium. Then get a GOOD ONE.

Make sure it uses A123Systems/Lithiumwerks chemistry cells. These will almost certainly be the standardized ANR26650m1B cell. Each cell being 3,3V 2.5aH. Because they are a standard cell the cell prices are dropping - but retail per cell is about 8euros (incl German VAT). They were closer to 10Euros. Some use the smaller 18650 cell - but need lots more. Other cells are out there - and are cheaper. But A123 are still after more than a decade - the best (OK except maybe Custom Tesla cells).

A good 7.5aH based on A123 with all BMS etc will be about 200Euros.

If I were fitting one to the 790Duke I might drop to a 5aH. On R3 or Guzzi - at least 7.5aH and tbh I'd feel safer with 10aH because I understand how they draw power. But on the whole - for my use - as things stand - I think I'd do the lead-acid battery and Li booster pack thing.

That may have helped - or maybe not.
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Another brilliant write up by this gentleman. Guys, we are lucky to have him on the forum. On behalf of all Duker owners, we appreciate the time , effort, and knowledge needed to provide such a well written report. I am on several other forums. (BMW K1600GT and Triumph speed triple) and the explanation about batteries types and selection criteria applies to all. Outstanding job.
 

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I did a load test on the stock battery . Stock battery (Haijiu) CCA 200 10Ah so carbon pile load tester used to apply 15seconds of load at 100 amp draw. Using multimeter and analog display on actual load tester from Harbor Freight, the voltage dropped to 8.6. On the bike, I captured the voltage dropping to 7.5 as I started bike and recorded TFT voltage display. New Yuasa battery was activated last night, charged overnight, and installed today. Looks like problem solved. My immobilizer failure warning was due to bad battery. If fails to remain fixed, I will be sure to update on forum. If any of you have not commented your experience with immobilizer failure and fix on this thread, please do so to help others
 

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I did a load test on the stock battery . Stock battery (Haijiu) CCA 200 10Ah so carbon pile load tester used to apply 15seconds of load at 100 amp draw. Using multimeter and analog display on actual load tester from Harbor Freight, the voltage dropped to 8.6. On the bike, I captured the voltage dropping to 7.5 as I started bike and recorded TFT voltage display. New Yuasa battery was activated last night, charged overnight, and installed today. Looks like problem solved. My immobilizer failure warning was due to bad battery. If fails to remain fixed, I will be sure to update on forum. If any of you have not commented your experience with immobilizer failure and fix on this thread, please do so to help others
Very good info. Thanks for sharing.
 
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