Do Lithium batteries really need new reg/rec s?

[BigLT]

I'm building a bike with my teenage son (modified 1980 GS250T) - he's done a good job and it's almost there, but I can't avoid doing the wiring any longer.

We want to use a lithium battery because i's so small and easy to hide away.

I've been reading up on the wiring and various places online say I'll need a special regulator rectifier for a lithium battery, but I can't find anyone saying this other than the people who are selling the things... and they're about £150 ish.

Does anyone know if I need one or not?

Is there a cheaper (and still safe) way of doing it?

If it makes any difference I'm also trying out using a motogadget m-unit I got in a deal...

thanks in advance

Liam

 

Edited July 24, 2023 by BigLT
mistake

[rodneya]

I would not trust the charging system on a 40 plus year old bike with a lithium battery.

[Arttu]

I assume we are talking about lithium batteries that are intended for bike use? Meaning LiFePO4 chemistry not LiPo which is used on RC batteries, phones, laptops etc.

These are compatible with lead battery charging voltages, more or less. So normal regulator is fine, assuming it works properly. Lithium batteries are less tolerant to over voltage so any overcharging will kill them pretty quickly. Also their nominal voltage is slightly higher so they need more voltage to get charged. If the charging system works properly this isn't any issue. But if the charging voltage is marginal, less than 13V, it's possible that a lead battery still gets somewhat charged and lithium one doesn't.

So as short answer, you don't need any special regulator. But make sure that the charging system works within the specs. And upgrading to some good quality modern regulator might be a good idea any way.

[Joseph]

On each of my 40 year old GSX bikes the first thing i had to do every time was replace the burnt out stator

Once that was done i fitted a cheap second hand Yamaha R1 (and many others) reg/rec : MOSFET FH012AA or FH020AA, along with a Lithium battery

The result was a stable 14.5V charge rate regardless of engine rpm, and alledgedly it ensures lower running engine heat.

Eitherway, you'll have no problems running a battery like you're planning on yours, like said above, if the wiring and charging system is in good nick. I would advise using that modern reg though, but no need to buy that fancy one you mentioned 

[imago]

As above but I would add one thing. Remake the charging circuit electrical connections, all of them. They're 40 years old and didn't use the best components even then so there will be poor connections with high resistance all over the place. It's such a commonly overlooked part of the system and yet is the main cause of both the original problems and also the "I've spent hundreds on a reg/rec, stator, battery and it won't charge properly/caught fire/burnt out the new stuff." issues.

Fitting the best MOSFET reg/rec (Shindengen BTW) stator and battery is pointless without making sure the wiring and connectors which carry their output are up to the job.

[TonyGee]

3 hours ago, imago said:

As above but I would add one thing. Remake the charging circuit electrical connections, all of them. They're 40 years old and didn't use the best components even then so there will be poor connections with high resistance all over the place. It's such a commonly overlooked part of the system and yet is the main cause of both the original problems and also the "I've spent hundreds on a reg/rec, stator, battery and it won't charge properly/caught fire/burnt out the new stuff." issues.

Fitting the best MOSFET reg/rec (Shindengen BTW) stator and battery is pointless without making sure the wiring and connectors which carry their output are up to the job.

spot on, I did the same thing on my GSX11 after fitting a new battery and MOSFET reg/rec.  perfect charging   

[BigLT]

Thanks all. Really helpful. The previous owner made a bit of a mess of it all, so I am replacing and redoing everything as i go.

I've only had chance for a quick look on Eblag and it seems like a choice between a cheap kit, or a second hand Yamaha or equivalent, but if I get a second hand decent one I'll need to sort the plugs etc.

Stator looks brand new, but who knows. It came with two reg/recs in a box of bits that both look wrecked, so I had planned to get a new one anyway.

I have some time to look at this next week. I never look forward to electrics, but at least I know now I can sort this without coughing up for some fancy part that costs about a third of what I paid for the bike.

Thanks Again

Liam

Edited July 25, 2023 by BigLT
mistake

[imago]

26 minutes ago, BigLT said:

Thanks all. Really helpful. The previous owner made a bit of a mess of it all, so I am replacing and redoing everything as i go.

I've only had chance for a quick look on Eblag and it seems like a choice between a cheap kit, or a second hand Yamaha or equivalent, but if I get a second hand decent one I'll need to sort the plugs etc.

Stator looks brand new, but who knows. It came with two reg/recs in a box of bits that both look wrecked, so I had planned to get a new one anyway.

I have some time to look at this next week. I never look forward to electrics, but at least I know now I can sort this without coughing up for some fancy part that costs about a third of what I paid for the bike.

Thanks Again

Liam

Have a look for a used reg/rec from a GS500 from around 2005 as they're Shindengen. There are plenty of low mileage bikes being broken and anything from the GS500 from the early 2000's is cheap as chips as loads get broken because they're not worth much.

Item number 195836987403 for example.

[johnr]

mosfet reg rec .

[Reinhoud]

Good question, I had the same issue.

I asked the seller, he said it would / should be alright, and 7000km later I haven't had any problems.

[Dezza]

Running a real-time volt meter after installing a lithium battery doesn't hurt and gives peace of mind regarding possible problems caused by voltage spikes.

[ral]

Thing is lithium batteries are very susceptible to overcharging, 14.4v is considered to be the top of the range on a 12v battery, some regulator rectifier’s charge over 14.4v, it’s this overcharge that gives concerns, also some chargers/ battery tenders for example will switch to DESULPHATE mode on a low voltage battery, this will generally charge at a rate above the 14.4 top end for a period of time, this can cook lithium batteries.

I for one will not be using lithium on older bikes systems that are not designed for lithium batteries.

If your going to use lithium I would recommend that the correct charger is used, and check your charging system is not delivering over 14.4v

[BigLT]

thanks again all

[gorbys]

I run one on mine but I also run a regrec from Rick's motorsport designed with a lower 14.1V charge since I read overcharging them can be real bad. Pluss I needed a new one anyways. Replaced all connectors with new ones from vintage-connections as well. 

 

[Joseph]

On 7/29/2023 at 11:11 PM, ral said:

Thing is lithium batteries are very susceptible to overcharging, 14.4v is considered to be the top of the range on a 12v battery, some regulator rectifier’s charge over 14.4v, it’s this overcharge that gives concerns, also some chargers/ battery tenders for example will switch to DESULPHATE mode on a low voltage battery, this will generally charge at a rate above the 14.4 top end for a period of time, this can cook lithium batteries.

I for one will not be using lithium on older bikes systems that are not designed for lithium batteries.

If your going to use lithium I would recommend that the correct charger is used, and check your charging system is not delivering over 14.4v

Daily used mine all year round all weather all seasons with no issues, the batteries are both now over 5 years old and have been handed down and used on the following bikes i've owned

[LLD]

I am running lithium batteries and felt that the original regulator was struggling to keep the voltage at reasonable level. So I changed it for one from Rick's which was specially configured for lithium usage with a little lower voltage.

Rock solid regulation of the voltage at 14v, regardless of the loading. Very happy with that