Mk3 Battery upgrade - Shorai LFX21A6-BS12

I was planning to upgrade the battery in a bone stock MK3 with a Shorai LFX21A6-BS12.
Will the stock alternator and stock voltage components work well with this battery?
Should I plan on other modern components to go along with this Shorai?

Anyone running this Shorai in an Mk3?



this looks like stock battery

Shorai recommend a voltage of at least 13.1V at idle which is unlikely on a commando, so probably not the best option if your doing town or urban driving

Another point to note is that the actual amphour storage capacity of the above battery when fully charged to 14.4 volts is around 7 amp hours.

Glen

I'm running Shorai's in four bikes. I installed a larger amperage battery in mine-18A. I have had good luck with three of the bikes going back four years. The Norton is untested but Shorai literature says if the charging system doesn't go above 15 amps you are safe. I installed a Podtronics regulator/rectifier on the Triumph and Norton. The Moto Guzzi has stock electrics as does the Buell.
I don't plan to putt around much with the Norton. I will be measuring the alternator output when the weather is better.

I put 2 batteries in like this. It works very well:
https://goo.gl/images/PyRPge

Pete Komarek said:

I'm running Shorai's in four bikes. I installed a larger amperage battery in mine-18A. I have had good luck with three of the bikes going back four years. The Norton is untested but Shorai literature says if the charging system doesn't go above 15 amps you are safe. I installed a Podtronics regulator/rectifier on the Triumph and Norton. The Moto Guzzi has stock electrics as does the Buell.
I don't plan to putt around much with the Norton. I will be measuring the alternator output when the weather is better.

Click to expand...

If its the LFX18 it has a pb/eq rating of 18 but actual storage of 6 ah.
Shorai and others use pq/eq rating to help market the product. Pb/eq is a one time quick discharge rate, something which Li batteries perform very well at for their size.
They do not do so well at handling parasitic loads or long running discharge situations such as a Lucas equipped bike idling in traffic with lights on.

Glen

p400 said:

i believe this is the stock Yuasa

Click to expand...

YB14L-A2

This is an issue I have been trying to understand for a couple years now. It is difficult to understand how to compare Lithium batteries and their charging requirements to lead-acid batteries. I'm not an electronics whiz, but if you can't use a battery maintainer designed for lead-acid batteries, what about the satisfying the charging needs with a standard Lucas alternator system, be it a 120 watt or 180 watt single phase or a 180 watt three phase? Are all of them capable of maintaining a fully charged lithium battery or will they result in early failure of this expensive battery? I hope some one more knowledgeable than me can shed some light.

at what rpm does a mk3 produce 13 volts?
is the voltage/rpm different with a podtronics regulator?

I have been running the (same) Shorai 18AH on my Alton E-start Commando since 2012. It has worked perfectly on the original Lucas rectifier/zeners as well as on a Podtronics which I installed later. The Alton alternator is a single phase 150 W unit - pretty much the same as the stock Lucas alternator that came on the bike. Despite the fact that in reality, the battery never get's fully charged (14.4V) it always spins the starter very rapidly - the bike starts from cold - amals tickled - literally instantly. Based on the voltage specs from Shorai, my system keeps it charged to around 75-80% of capacity - around 13.5V. My system with a Trispark ignition will provide 13V at 1100 RPM, maxing out at around 14V at 3k RPM. It does not go any higher regardless of RPM. With the OEM ignition my charge voltage is considerably lower - around 12.5 at 2kRPM, never getting above 13 due to the higher amperage draw due to the ballast resistor.

The voltage numbers for the OEM ignition came from my "experiment" of a week ago where I removed the TriSpark, installed the OEM ignition - points/Ballast resister, etc. I ran the OEM ignition for a few days then removed it/reinstalled the TriSpark

I am not comfortable recommending a lithium ion or lithium polymer battery to anyone that has the standard charging system on a bike, or even a podtronics type of regulator/rectifier.

For me, I like to see a minimum spec of a series type regulator/rectifier as used on a modern bike before you use a lithium-based battery. Exactly what we’ve fitted to the MK3



Just look at phones and tablets exploding on planes. The massive recall of the Samsung devices in 2017, the freak fires where kids leave devices charging on their beds.



Then look at the electric cars catching fire.
And all this modern kit has special chargers designed for the job in hand!!!!



Now consider you have the same type of battery being charged by a very antiquated charging system, above a red hot engine that shakes and rattles (even with isolastics) and you are sat astride a tank full of petrol.

I just don’t like the idea.


The original silicon full wave rectifier (half wave on the MK3) and zener diode (times two for the MK3) outputs your excess charge as heat when your battery is fully charged, but there is no ‘logic’ that is checking that charge rate or the over charging.

A podtronics is similar, but worse, the circuitry keeps your alternator dead shorted (described as some asunder 100% load, but it's far worse than that in reality) for 100% of the time. One of the reasons we are seeing more alternator failures (in my opinion)



These are $3 components encapsulated in resin on the underside of a large heatsink.



At least the branded Podtronics units are wired up correctly, potted with resin that actually transfers heat, and use wires that are thick enough to carry the current.

The cheaper $20 units may look the same but they are not assembled with the same care.


So I guess my answer is yes, I recommend you plan to install some other modern components alongside your Shorai

So are you saying Podtronics rectifier/regulators are causing rotor/stator meltdowns?

FWIW, the OEM Lucas rectifier/Zener produced a slightly higher charging voltage when I did my "test" than did the Podtronics.

Gtiller - As far as all the "bad" things mentioned about Li batts, I can only point to my personal experience (with only one such battery I readily admit that's not much of a "sample!). But the Shorai has lasted far longer than any other motorcycle battery I have ever owned on any motorcycle. Despite the charging system not being correct for the battery, it has worked fine. I will buy another one when this one finally dies. I am in a moto club in Mexico and most of the riders in the club either have switched to a Shorai or plan to switch to one when they need a new batt.

I am not disputing your knowledge or experience with LI batteries, just saying that the Shorai has worked fine on my E-start Norton for 7+ years.

Ive had two Li batteries , Ballistics, both running with Altons and Podtronics.
One battery lasted about 14 months then died, no damage to the charging system.
The other battery lasted 18 months. When that battery melted, it took out the Alton and Podtronics.

So I'm a little gun shy on the Li batteries.

Shorai might be a better battery than Ballistic.

Glen

worntorn said:

Ive had two Li batteries , Ballistics, both running with Altons and Podtronics.
One battery lasted about 14 months then died, no damage to the charging system.
The other battery lasted 18 months. When that battery melted, it took out the Alton and Podtronics.

So I'm a little gun shy on the Li batteries.

Shorai might be a better battery than Ballistic.

Glen

Click to expand...

Now I understand your hesitance Glen...

I’d be anti Li battery if that had happened to me too!

gtiller said:

I am not comfortable recommending a lithium ion or lithium polymer battery to anyone that has the standard charging system on a bike, or even a podtronics type of regulator/rectifier.

For me, I like to see a minimum spec of a series type regulator/rectifier as used on a modern bike before you use a lithium-based battery. Exactly what we’ve fitted to the MK3

View attachment 8921

Just look at phones and tablets exploding on planes. The massive recall of the Samsung devices in 2017, the freak fires where kids leave devices charging on their beds.

View attachment 8920 View attachment 8919 View attachment 8913 View attachment 8917

Then look at the electric cars catching fire.
And all this modern kit has special chargers designed for the job in hand!!!!

View attachment 8915

Now consider you have the same type of battery being charged by a very antiquated charging system, above a red hot engine that shakes and rattles (even with isolastics) and you are sat astride a tank full of petrol.

I just don’t like the idea.


The original selenium rectifier and zener diode output your excess charge as heat when your battery is fully charged, but there is no ‘logic’ that is checking that charge rate or the over charging.

A podtronics is similar, but worse, the circuitry keeps your alternator under 100% load 100% of the time. One of the reasons we are seeing more alternator failures.

View attachment 8918

These are $3 components encapsulated in resin on the underside of a large heatsink.

View attachment 8916

At least the branded Podtronics units are wired up correctly, potted with resin that actually transfers heat, and use wires that are thick enough to carry the current.

The cheaper $20 units may look the same but they are not assembled with the same care.


So I guess my answer is yes, I recommend you plan to install some other modern components alongside your Shorai

Click to expand...

Grant, can you please offer a bit more of a ‘Janet and John’ description for the Luddites (especially me)?

Exactly which modern rectifier / regulator do you use?

How is it wired up?

What else is required to be done to the system in order to fit it?

Is it compatible with Tri Spark and digital clocks?

Are we sure it’s better? As you said, the modern vehicle fires had modern electronics but still combusted. Have any classic bikes with Li batteries combusted ?

It’s all a black art to me! I’d gladly follow your lead and advice on this...

As I say, just an opinion on my side - of course other opinions will be different.

@Ron L yes, I think we are seeing more frequent failures for two reasons:
1) the modern units keep a full load on the alternator coils all the time (call it a dead short if you like) this makes them run terribly hot.
2) new alternator rotor/stator combos are made with less clearances (smaller air gap) which means if there is any misalignment or crank flex, there will be contact. Obviously this can be catastrophic.

@MexicoMike don’t get me wrong - I really like Shorai kit, I rate the quality highly and recommend them. It spins the starter on the MK3 effortlessly.
I just like to see the components around it updated to match.

@Fast Eddie my testing was limited to a multimeter bench testing over a long period of time before I picked the route I wanted to take.
Our friend @Jeandr did a LOT of testing with oscilloscopes and is far more technical. Have a look at his post here https://www.accessnorton.com/NortonCommando/voltage-regulators.19023/

The series regulator/rectifiers are wired up exactly the same as the podtronics types.
Three yellows ‘in’ and a red & black out.
Works with positive or negative earth bikes, and you use a pair of yellows if you only have a single phase alternator.
The downside is because this technology isn’t yet used in the mass market, they are not doing high product rubs to bring the cost down.
Expect to pay around £100 for the series type regulator/rectifier.
The components inside are essentially the same as in a podtronics type, but they are wired differently.

Put simply - with a series type unit, when the battery is charged, the circuit on the alternator side is opened, taking the load off the windings in the stator.
Result is, both units (reg/rec and stator) run a lot cooler.

The podtronics type by comparison keeps the alternator coils under full load, and instead converts the charge to heat instead of routing it to the battery.

The original zener diode (the bit that deals with over charging) leaks excess charge to earth in a similar way.
The selenium based rectifier (the bit that converts AC to DC) is only half as efficient which doesn’t load up the alternator as much as modern electronics.



Have a read of Jean’s post - it goes deep but is very interesting.

I read Jeans post. It didn’t take me long. That’s NOT because I’m clever... it’s becasue I skipped over the stuff that was over my head...!

So, in summary the SH775 regulator is the one to go for, correct?

And this will live happily with a Shorai battery, correct?

I also gleaned from Jeans post that if you do run a Pod unit, run normal bulbs (not LED) and keep your lights on at all times and that will help balance out the load issue. Interesting as we’re all madly fitting LEDs to our bikes currently !!

The alternator on my Commando showed signs of heat / distress and needs replacing. I put this down to the rotor touching the stator, but perhaps it is due to the Podrontic / LED combo I’ve been using?

This is the alternator stator I took off my Commando recently. It shows signs of rubbing and heat. I had assumed they were linked. I’m now wondering if part of the problem is this Pod issue?
I had a .010” gap. The rotor is only touching in parts and I suspect this is due to crank flex.
I have a new stator, it’s currently being measured to ensure concentricity to the mounting studs, the rotor is being checked for roundness. Assuming it all checks out, I’m turning the rotor down to give a .020” gap all round.

@Fast Eddie great summary Nigel!

The Harley boys are starting to light up to the benefits of series type units now, so there are a few more coming into the market. Most of these are big, blingy and shiny though.

I like the Shindengen units, as they are quiet, unassuming and come in the same package as mosfet and shunt type reg/recs that we are all familiar with.

They are trying to phase out the SH775 in favour of their latest models.
I think they see the SH847 as the replacement, as it’s been tweaked to better handle a wider (and much higher) rev range.

The pic in my post above is the SH775.
We recently moved it so we can get an original style air filter in.