Motorcycle and Scooter appreciation

Don’t they need a Mosfet that outputs a current voltage that doesn’t kill the battery?

https://www.motoelectrical.co.uk/types/regulators-/lithium-ion-batteries-compatible-mosfet-voltage-regulator-rectifier-atv-utv-motorcycle-snowmobile-pwc-scooter/

Seems odd as some vehicle charging systems run at 13.8v while others run at 14.4v, you'd expect a fit and replace option of lithium batteries not have issues. Especially as the batteries I have seen are supposed to be direct replacement.

This may be why some people have had a fit and forget, and others have replaced lithiums more often than oil. Maybe it depends on the bike more than anyone would like to admit.

There have been fires on lithium equipped bikes and it burns very well. I think the reg/rec is overheating when the alternator is at full chat for too long. I'm trying to figure out what might be happening to cause that.

Normally it's too many amps, but because?

Maybe lithium goes into a higher current draw in a range of voltage.

Or the reg/rec can't dump as much current to the lithium as a lead acid so it ends up soaking up extra current in heat.

Well that link I posted seemed to say something about cutting off when too hot, so possible that lithium is just too sensitive for retrofitting on otherwise crude electrical circuitry?

I should have read that!

Now I'll have to spend some money.

Needs 13.6 - 14.4v.

I have them on the GSXR and the Duc (and that has crude electrics.)

Anything with a semi modern Reg / Rec should be fine.

In that case maybe move the reg/rec in to air flow and or maybe install a fan.

Having them in airflow, or on a heatsink is a good shout. I mounted the one on my XR on 1/8th" Aluminium plate, which wicks heat really well. Every little helps.

If you want, and have space for it, you could fit a small CPU heat sink and fan.

I have a few from computers in a box and can possibly get a friend to supply some for almost £0.00. Most CPU fans are 12V, which means they will wire up without much trouble.

Depending on regrec location, thermal paste to the backside, extra heat sink. Otherwise simply put a 12v fan on the front. If you were going crazy then you’d use a thermal switch for on/off but personally I’d just have it running all the time.

Just an idea.

I may have missed it, but what is the voltage on your battery?

My scrambler needs a high voltage to turn over. People often upgrade the rectifier to fix it.

Things you learn from owning ultra reliable hondas ;)

If your bike reg/rec looks like this

(lots of hondas) To the blackbird owner, check the reg/rec has been changed.
then it is a matter of time till it is buggered,
Replace with a rec/rec that has more cooling such as this

NC30/35 reg/rec is one of the many off the top of my head

+1 for the use of thermal heat sink paste on the back of the regulator/rectifier. My blade's charging system is super reliable now.

edit: I replaced the reg/rec about 10 years ago (I feel old saying that) with a Mosfet one, and it mounts to the bike's aluminium rear subframe where I cleaned it and used the silver heat paste. This dissipates the heat very well.

My bike has a slightly daft REC/REG location, under seat above mudguard where it and everything else stays very dry, but there is zero airflow, zero!

Few folk have soldered on longer wires and moved it under the mudguard. Might just paste on an even larger heatsink for it

It's in slow/stationary city traffic with little to no air flow that problems might occur, which is why it's best to heat sink it to something metal with a lot of heat dissipation potential. As lynx said, the finned reg/recs are best too.

I'm actually finding the opposite. It's only happening at maximum speed on open roads. I guess due to the higher output of the alternator at constant high speed. The BMW R80 charging system has books dedicated to understanding it though.

Most of the finned reg/recs aimed at retro fitting on the R80 specify not suitable for lithium batteries. I'm sure manufacturers are covering themselves and they may be better than existing but it seems they need to be operating in a small range of output voltage to work with lithium while also having very small amounts of ripple.

Different cans of worms here. I have a Yuasa lead acid battery on the blade, but I delved into lithium with my ZX12R which suffered from overheating the actual battery itself. The battery was located inside the frame right behind the engine, where if it was hot and the bike sitting or moving slowly through traffic, chronic heat soak occurred. Often, in city traffic if I stalled the bike, it wouldn't start until it cooled down, which often took 20 minutes or so, but then it would start on the button. Nightmare! Lithium ion batteries are supposedly much better at operating in the sort of temperatures that were happening here, so I switched over. Unfortunately I sold the bike before I really gathered a lot of experience with it, but it had seemed to have solved it.

From what I've read though, lithium batteries will take very large charging rates, so it puzzles me why some of the voltage reg/recs aren't suitable, unless as you suggest they might not take the ripple.

Like you I assumed a modern adjustable reg/rec would allow you to set an appropriate charging voltage and that would be enough. Most of those types are coming with specific warnings about suitability with lithium though.

I don't want to go back to AGM or lead acid types though.

As you mentioned though, they are probably just covering themselves. As long as you think carefully about your choice and set it up well, maybe try one and keep an eye on things? ... your choice really.

I agree. Modern Reg/Recs are much of a muchness - there's nothing unique about them.

The version that pdlouche linked to ticked all the boxes as far as spec is concerned and for £40 more than the normal 'not for lithium' type that makes sense to me. I'll contact them and see what kind of assurances they are prepared to offer.

The alternative is trying to find out voltage range and ripple on the standard types to see how different they are.

Could try out the old mechanical version that's been in a box for ten years!

Not particularly to Jung

As I learnt a few years ago, (maybe a decade ago,can't be that long ago can it) that all modern bikes don't have mosfet regulator some will be mosfet and others aren't on the same model bike. They look the same but have different models number to identify the type used.

More details here from a usian hawk forum: https://www.superhawkforum.com/forums/knowledge-base-40/mosfet-regulator-rectifiers-why-how-25117/

Any luck on this?
My Tiger did the same.

Was the starter for me personally. Brushes were worn out. They can also get stuck.
Not sure where the starter is for you, but for the 800, it's in a garbage location. Wedged just behind the heads, so they get the full heat blast as you ride.
As a quick fix, I replaced the brushes and it's been dandy since, however, in the middle of summer, it does hiccup starting. When it goes again, and it will, I'll be getting a Rick's starter, which are way sturdier.

Again, not sure where the starter location is for you, but it's a fucking bastard of a job to take out. You need patience and decent tools.

Either type of regulator is fine, they work the same. Mosfet ones just switch faster for more stable voltage and less heat (which is a definite plus.)

They're super easy to fit, I run a lead direct from the DC out to the battery with an inline fuse.