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Discussion Starter · #1 · (Edited)
I'm starting this thread to pull together and update the excellent advice I've read on this site, some of which goes decade+ back (re mosfet regulators) and still seems to be valid, but now becoming even more important as LiFePo4 batteries get more powerful and (relatively) cheaper.
 

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Discussion Starter · #2 · (Edited)
My case:
I'm on a 97 carbie. Ran lead acid bat for first 15 yrs. Changed to Shorai LiPo last 8 years regularly swapping between two bats (using a Shorai bespoke charger) and ridden regularly. No battery tender. I've killed them both.

I've only needed to change a faulty r/r (regulator/ rectifier) once. I can't remember if that included upgrading to mosfet but may explain me killing my Shorais if not mosfet!

Mosfet is better tech which from what I've read, smooths the function of the r/r stepping the balance from fully recharging the battery to fully dispersing unwanted generated AC/DC to ground (resulting in less heat dissipation). Old tech was all or nothing (full on recharge or sudden full on heat generation). Extremes (esp sudden heat = not great for batteries or electrics). Mosfet can gradually change the balance of the two and mode of coping with excess current.

Now as we switch to LEDs (headlights, tail lights, indicators, dash bulbs etc) we reduce our ampage needs (at the cost of making the heat dissipation topic harder for the r/r increasimg risk of burning them or the stator out faster).

Yet on the other hand we add more power hungry ancils to power as we ride along (esp heated grips, seat, clothing, GPS, satnav, phone, bluetooth, USB ports etc). That eats up excess power.

Taken to an extreme that may results in the bat not being recharged fully so your potentially dead for next time you hit the starter button! So a balance is needed between the two and one solutuon (as yet) doesn't necessarily fit all as we all have dif mods/ upgrades).

Added to that LiFePo4 bats bring creater power to the table (and mine even has a built in jump start function so in theory I've got a back up solution to too many mods draining my bat).

However LiFePo4 need a gentler charging profile than lead acid and Mosfet seem best suited to provide that else you kill you expensive battery quicker or worse have it explode! Ouch!
 

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Discussion Starter · #3 · (Edited)
I've just bought an Antigravity 16Ah 480 CCA LiFePo4 so need to protect the bike and bat from the downsides of each other while maintaining the upsides.

So R/R choice:
From what I've read a Shindengen FH012AA mosfet R/R will do spec wise and ought to physically fit a carbie (on left side poss with bracket mod). It is rated at 50A max. It seems to have a great reputation with users on this site and Jack comes well recommended as a supplier (inc kits). I'll add a link in a mo.

So is my old wiring good enough to cope with <10s of up to 480 CCA? Fuse choice upgrade too?

I'm very interested to hear if there is better recommendations out there that will still physically fit (I'm mindful of stories of cheap knockoffs, advice to attach direct to the battery, go for hi as poss max amp capacity, improved grounding (inc use of heat paste) to help with heat loss and waterproofing connectors).

Thoughts, corrections, updates advice and R/R recommendations all welcome (and truly needed)

Rgds Mallow1
 

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Don't bother with the FH020AA from Jack's. Go the whole hog and get the SH847. I run a Shorai alongside one and had no issue's.
 

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I'd say your wiring should be fine.
The positive lead from the battery to the starter relay, then from the relay to the starter is a heavy lead.
The relay is just a "heavy switch" to connect the battery to the starter, there are no fuses in this line.
The 30amp fuse on the starter relay is the main fuse, from the battery lead into the relay, it supplies a feed to the ignition switch.
The ignition switch, switched on, supplies power to the smaller fuses to protect specific circuits.
 

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Discussion Starter · #7 ·
Don't bother with the FH020AA from Jack's. Go the whole hog and get the SH847. I run a Shorai alongside one and had no issue's.
Hi Adey,

Obvs the two are different but I'm finding difficulty google comparison between the two re tech specs & user insight. Most of what I find is back in 2018 when 847 was pretty new with limited user feedback and limited OEM uptake. Really great to hear you've had no problems but what would be the advantage of the 847 over the 20AA? Why'd you go the full hog roast?

Any insight re comparison appreciated?
 

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Discussion Starter · #8 ·
I'd say your wiring should be fine.
The positive lead from the battery to the starter relay, then from the relay to the starter is a heavy lead.
The relay is just a "heavy switch" to connect the battery to the starter, there are no fuses in this line.
The 30amp fuse on the starter relay is the main fuse, from the battery lead into the relay, it supplies a feed to the ignition switch.
The ignition switch, switched on, supplies power to the smaller fuses to protect specific circuits.
Thanks Punts… I was about to settle down with the wiring diagram to appraise the situ. While the antigravity comes with it's own built in BMS (battery management system) capable of putting the bat into "sleep mode" if it drops beneath a threshold voltage, I've been a long time user of "PriorityStart" so I'm overly complicating my life working out if this is now redundant or if not, where to stick it in a new set up.

Great to know you think the wiring is up to coping with the higher CCA. Thanks.
 

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Hi Adey,

Obvs the two are different but I'm finding difficulty google comparison between the two re tech specs & user insight. Most of what I find is back in 2018 when 847 was pretty new with limited user feedback and limited OEM uptake. Really great to hear you've had no problems but what would be the advantage of the 847 over the 20AA? Why'd you go the full hog roast?

Any insight re comparison appreciated?
Mallow
I had a discussion with jack on this very subject years ago. At that time there was only one manufacturer making series regulators for bike. They were a Harley Davidson aftermarket maker. They were only interested in HD.
Jack stated that at that time he only recommended the series for track bikes. The unit allowed the customer to disconnect lighting and not burn out the stator because of the way it effected the power.
Fast forward to now where technology has created LED's bright enough to be used as main light beams at a greatly reduced power demand. So you now have basically taken a street bike and set it up in a modified track condition because of the reduced system loading.
So I'd have to recommend if your not fully LED'd out save the cost and run the SH20
 
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Mallow, the whole thing is counter intuitive, less electrical load makes the R/R work harder, and visa versa. The harder it works the hotter it gets. If you convert to all LED, then you are making the (standard issue or FH020AA) R/R work harder. This is where the 847 differs, in that instead of sending excess electrical energy to ground through some kind of resistance, it creates an open circuit instead. As you probably know, with any electrical component, heat is your enemy.
 

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Discussion Starter · #11 ·
Fizzy, yer it get the diametrisity of the situ.

The stator just pumps out the juice. That juice needs to go somewhere. Options being:
a) recharge battery (until full) NB amp/ voltage profiles important re type of battery
b) run bikes electric requirements when running inc all ancils
c) dump excess (if any) somewhere, typically to bats -ve terminal/ ground and/or dumped as heat.

The R/R ensures that AC from the stator is:
1) converted to DC
2) manages the voltage of the resulting DC to within a specific range (old tech suited to lead acid bats, latest suited to inc LiFePo4 requirement; the two being potentially different)
3) supplies a-c above

Old-school tech does that in binary (all or nothing) manner. Mosfet does that gradually. Result is mosfet copes with more types of bat types (inc LiFePo4) and runs cooler.

Have I got that right so far?
 

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Discussion Starter · #12 · (Edited)
Hi Adey,
Obvs the two are different...
Any insight re comparison appreciated?
Aha… now, educated myself to how a "series" rr works compared to a "shunt" rr and SCR v Mosfet (old tech v new tech) works.


The SH847 is a series rr so only draws the current needed so the stator isn't working at 100% output all the time. So there is limited excess power needing to be disposed of. Therefore this unit doesn't need to be Mosfet to dispose of that without excessive max temp. It is SCR. Both it and the stator run cooler as a consequence of being "series" and hence are more robust/ reliable/ stable.

NB Read a thread postulating that since the stator isn't at 100% output all the time under a "series" rr it is less of a load/ drag on the engine so a modicum of hp is no longer taken up in power generation. So in theory more hp to ride with and/ or better fuel consumption. Hmmm…

Now the FH020AA is still a "shunt" rr (so stator always at 100% power gen) but uses Mosfet tech to manage and disipate excess power (shunt) more efficiently so runs cooler than an SCR shunt rr dealing with the same situation. Because of Mosfet's ability to quickly and gradually manage voltage changes (and heat dissipation) it sounds as if it is therefore more suited to LiFePo4 charging.

So it sounds to me that a series rr with Mosfet tech is the utopia for a BB using a LiFePo4 bat i.e. cooler temps, matched battery charging profile, protecting LiFePo4 from damaging voktages and arguably a modicum of better fuel consumption as some isn't burnt generating surplus electricity which only gets dumped as wasted heat… the heat being a danger to stator, rr and bike general electronics re burn out/ shorter life spans).

That utopia doesn't seem to be found by me yet but in the meantime the SH847 sounds defo the way to go though the cheaper FH020 would suffice!

There are of course other specs which make either of these units a great improvement over stock or suitable for an engine capable of high revs (sports bike v lower reving cruising style bikes) re max amp capacity (50A max) and stable voltage management and Li battery usage but limited interest bumping my gums further here.

Have I got any of this wrong?
 

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Discussion Starter · #13 · (Edited)
From other threads the SH847 will fit an FI bird over on the OEM location (right hand side) and for carbies (and some early FIs) it is tighter but will still fit in the OEM location on the left hand side.

Beestoys posted a template for a bracket to do the job on the LHS (inc a note saying the bracket allows for a touch of tilt away from the subframe to help achieve the best fit).

PBZ
So sorry this took so long to get to you

View attachment 120463
 

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If there is a MPG gain with series type R/R then it would be measured in extra yards/tankful :unsure:
 

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Discussion Starter · #15 ·
LMAO… 😂 You're prob not wrong there. If I get really really bored sometime I'm sure we could calc a theoretical approximation and see how far we'd have to ride for the higher price of the SH847 to pay for itself via that dynamic! It's prob going to pay for itself in longer stator, battery and its own lifespan way quicker!
 

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Discussion Starter · #16 · (Edited)
So it sounds to me that a series rr with Mosfet tech is the utopia for a BB using a LiFePo4 bat…
That utopia doesn't seem to be found by me yet…
Oooh… Rick's Motorsport Electrics (who seem to be a very reputable US manufacturer) build a Series R/R with Mosfet for our Birds (part #10-134H). Now got to check if it's LiFePo4 compatable.

[Edit:] Hmmm… I wonder if I'm assuming Hot Shot Series refs to a Series R/R or whether it's in ref to the Hot Shot "range" of products. I'll dig some more.

Priced at $153

Anyone got any experience of them apart from BirdBrain's comments from 2012 saying problem with a unit but well dealt with by Rick's?
 

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Discussion Starter · #17 · (Edited)
Great explanation (see link below) of charging stages and voltages of Sealed Lead Acid (SLA) batteries versus Lithium/ LiFePo4 ones. Reason why I'm being cautious is a lot of lithium RRs say "not for SLA use, lithium only". My concern is if my lipo fails for whatever reason then I may wish to throw in a good old SLA without having to swap RR too. So can I find an RR spec'd to cope with the two safely.


Basically the explanation says Lithiums should not be exposed to a charging voltage greater than 15.7 volts (damage or worse) and ideally not allowed to drop beneath 12.5 volts (NB at 11v potentially unrecoverable deep discharge). Prudent range therefore seems to be 13.7-14.7 volts so a lot of RR manufacturers aim to have 'set point voltage" at 14-14.2v +/- 0.2v

So it looks like an RR set at 14.5v isn't quite ideal for either type of battery but could cope with both SLA and Lithium without damageing either so long as it's a quality one (i.e. swift to respond to voltage spiking outside that value).

Now my battery choice has a built in BSM (battery management system) which affords an extra degree of protection against brief periods of too hi or too low voltages for an RR operating normally (though not 100% bullet proof against RR failure).

The final piece of the picture therefore I think is to ensure the RR can cope with sustained hi RPMs without failure (bearing in.mind our BB's, are Jap "screaming crotch rockets" who red line at 11k rpm not USA "Hardly Dangerous" low reving easy riders). So for example FH020AA (mosfet parallel shunt) and SH847 (SCR series shunt) can whereas an SH775 can't and is reported as prone to fail at hi RPMs.

Gosh… who knew this was so intricate a selection process!
 

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Well Mallow
I'll add a one real world experience. I have on 2 occasions deep cycled my shoria. once with the SH12 and again with the 847. It's still I. here and working. I do on occasions see 14.7 on my volt meter. But my amps at freeway will actually swing negative. This leads creadance to your observations of the R/R uncoupling. I saw the same action out of the SH12. It doesn't go a large negative typically at 42 4500 rpm it's - 3.5 to - 3.7 amps. Total draw on the system as I have it configured is 11 amps. The SH12 would do the same, at lower surface streets it will swing closer to zero. This leads creadance to the postulation again that it uncouples to the demand. My reasoning based on the 2 meters readings is that I see amperage dropping less negative because stator output drops off at lower rpm. But myvoltage stays rock solid at 14.6.
 

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Discussion Starter · #19 ·
So far the SH847 still seems to be undisputed top dog.

Great to hear your real-world observations are in line with the info I'm digging up to educate myself before I splash more cash.

It's even proving hard to find alternative series r/r units to compare the SH847 against. I do now think the "Hot Shot Series" label on the Rick's units I looked at refers to the range of products not the tech (series v shunt).

So pleased your typos get as bad as mine😱! I tend to have to repeatedly edit my posts ten fold to make them vaguely readable from my initial fat finger typos, auto corrects and just bad spelling! I need another 🍺🍷🥃
 
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