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I am thinking of using a Lithium Ion Battery in a DC circuit instead of a Burglar alarm Battery.
Is there anything different in the way a Li on Battery charges while the scooter is running?
I know that both charge at 14.25 v
I have read that Li on Batteries do not like being overcharged so is there a way of preventing this?

If you don't exceed the charging voltage, it won't overcharge.

Lithium ion batteries can become very dangerous incendiary devices. Not a good idea when your battery likely resides next to 2 gallons or more of highly volatile petrol!
Charging them requires electronic management to control the charge in constant voltage as well as constant currrent mode.
Your Lammy uses a primative shunt regulator which is barely adequate to control the charge of a lead acid battery.
So, my advice would be to bin the idea.

Fast n Furious wrote:Lithium ion batteries can become very dangerous incendiary devices. Not a good idea when your battery likely resides next to 2 gallons or more of highly volatile petrol!
Charging them requires electronic management to control the charge in constant voltage as well as constant currrent mode.
Your Lammy uses a primative shunt regulator which is barely adequate to control the charge of a lead acid battery.
So, my advice would be to bin the idea.

They are sold as replacements for Vespa PX models which are virtually same trickle charging system as a Lambretta? Wouldn't that be dangerous too?

It's a vesthpa.... so it doesn't matter.

Leotech wrote:

Fast n Furious wrote:Lithium ion batteries can become very dangerous incendiary devices. Not a good idea when your battery likely resides next to 2 gallons or more of highly volatile petrol!
Charging them requires electronic management to control the charge in constant voltage as well as constant currrent mode.
Your Lammy uses a primative shunt regulator which is barely adequate to control the charge of a lead acid battery.
So, my advice would be to bin the idea.

They are sold as replacements for Vespa PX models which are virtually same trickle charging system as a Lambretta? Wouldn't that be dangerous too?

And many other vehicles too. I've got one on my triumph for example. But I guess it depends on what level of confidence you have in your charging system. And a typical lambretta system is a little unpredictable to say the least. Personally, if I have a good quality reg/rec fitted, AND it's a high quality installation, I'd be happy to use one.

Fast n Furious wrote:Lithium ion batteries can become very dangerous incendiary devices. Not a good idea when your battery likely resides next to 2 gallons or more of highly volatile petrol!
Charging them requires electronic management to control the charge in constant voltage as well as constant currrent mode.
Your Lammy uses a primative shunt regulator which is barely adequate to control the charge of a lead acid battery.
So, my advice would be to bin the idea.

That was one of my concerns, I wondered if any one had worked out a way to control the current.
I did think of a capacitor but I am not that clever when it comes to electricky.

I have had a Li-Ion fitted for a few years and seems to be performing much better than the previous lead acid one did which seemed to go flat weekly.

Mine is charged via a BGM / Varitronic type regulator / rectifier . I've not had to touch it for 3 years or so. It powers a decent 12volt DC horn and a leg shield spot lamp. Its a Vespa PX equivalent battery one as its virtually same electric as a PX. it also fits in a standard Lambretta battery tray.

It's got fuses in at both sides too 7.5 amp same as the PX


Just worried now its going to explode!

dickie wrote:

Leotech wrote:

Fast n Furious wrote:Lithium ion batteries can become very dangerous incendiary devices. Not a good idea when your battery likely resides next to 2 gallons or more of highly volatile petrol!
Charging them requires electronic management to control the charge in constant voltage as well as constant currrent mode.
Your Lammy uses a primative shunt regulator which is barely adequate to control the charge of a lead acid battery.
So, my advice would be to bin the idea.

They are sold as replacements for Vespa PX models which are virtually same trickle charging system as a Lambretta? Wouldn't that be dangerous too?

And many other vehicles too. I've got one on my triumph for example. But I guess it depends on what level of confidence you have in your charging system. And a typical lambretta system is a little unpredictable to say the least. Personally, if I have a good quality reg/rec fitted, AND it's a high quality installation, I'd be happy to use one.

Can you define a High quality installation?

scarkey wrote:
Can you define a High quality installation?

That's a tricky one actually, despite that being a large part of my job. There is no absolute definition and even if you follow some of the best defined standards around, like DNV, it's still possible to comply with them and do a sh1t job. But I'll give it a go anyway.....

For a lambretta charging system, I think you could limit the requirements to:

-Good quality wire with sufficient cross section for the maximum continuous current
-flow solder into any crimped connections
-apply grease to any terminals
-clean terminals properly before connecting
-all terminations are tight
-no loose components, thereby avoiding vibration damage
-a good earth connection between frame, engine and charging system

dickie wrote:

scarkey wrote:
Can you define a High quality installation?

That's a tricky one actually, despite that being a large part of my job. There is no absolute definition and even if you follow some of the best defined standards around, like DNV, it's still possible to comply with them and do a sh1t job. But I'll give it a go anyway.....

For a lambretta charging system, I think you could limit the requirements to:

-Good quality wire with sufficient cross section for the maximum continuous current
-flow solder into any crimped connections
-apply grease to any terminals
-clean terminals properly before connecting
-all terminations are tight
-no loose components, thereby avoiding vibration damage
-a good earth connection between frame, engine and charging system

Thanks Dickie for your input.

I've been using these for a few years now on a Varitronic full DC Wassel system and not had a problem https://www.ebay.co.uk/itm/141565401435

As a follow up to what said 2 weeks ago I fitted a Li Ion battery to a friends Lambretta after my favourable experiences.

All was well until it started to melt. We'd been out on a ride together, Both the Lambrettas had same charging system BGM type reg, I had checked the trickle charge rate etc. before it was used and all. It had a fuse 7.5 amp on the charging side and the supply side, both the fuses were intact. Now i'm left wondering why mine had been fine and his wasn't despite being exactly same batteries with everything pretty much the same.

I got the battery via trade account I have and they are going to talk with the manufacturers. It has put me off putting Li Ion batteries on anything now, that said I will continue to use one on my Lambretta and monitor it. I am beginning to think it's a faulty battery rather than a general issue.

Leotech wrote:As a follow up to what said 2 weeks ago I fitted a Li Ion battery to a friends Lambretta after my favourable experiences.

All was well until it started to melt. We'd been out on a ride together, Both the Lambrettas had same charging system BGM type reg, I had checked the trickle charge rate etc. before it was used and all. It had a fuse 7.5 amp on the charging side and the supply side, both the fuses were intact. Now i'm left wondering why mine had been fine and his wasn't despite being exactly same batteries with everything pretty much the same.

I got the battery via trade account I have and they are going to talk with the manufacturers. It has put me off putting Li Ion batteries on anything now, that said I will continue to use one on my Lambretta and monitor it. I am beginning to think it's a faulty battery rather than a general issue.

May not be the issue in your case but always a good idea to consider heat and vibration when mounting anything on a Lambretta

Leotech wrote:As a follow up to what said 2 weeks ago I fitted a Li Ion battery to a friends Lambretta after my favourable experiences.

All was well until it started to melt. We'd been out on a ride together, Both the Lambrettas had same charging system BGM type reg, I had checked the trickle charge rate etc. before it was used and all. It had a fuse 7.5 amp on the charging side and the supply side, both the fuses were intact. Now i'm left wondering why mine had been fine and his wasn't despite being exactly same batteries with everything pretty much the same.

I got the battery via trade account I have and they are going to talk with the manufacturers. It has put me off putting Li Ion batteries on anything now, that said I will continue to use one on my Lambretta and monitor it. I am beginning to think it's a faulty battery rather than a general issue.

There must be millions of Lithium Ion batteries in use around the World & they are the norm for cordless tools for a great number of reasons. Bearing that in mind, with the working proximity of battery to user in such cordless tools, I suspect they offer very little risk in normal circumstances. They must be the most rugged of all the types of batteries available to the public.

Unfortunately, they can also suffer the 'false memory syndrome' but there are tricks that can be applied to overcome such an issue. Two of my Milwaukee 18v batteries suffered from it & one was easily corrected whilst the other may need cells replacing.

Anyway, it seems to me that anybody in the market for a battery to suit their 12v scooter might consider buying into a 12v cordless tool system & benefit from the options that offers.

Leotech wrote:As a follow up to what said 2 weeks ago I fitted a Li Ion battery to a friends Lambretta after my favourable experiences.

All was well until it started to melt. We'd been out on a ride together, Both the Lambrettas had same charging system BGM type reg, I had checked the trickle charge rate etc. before it was used and all. It had a fuse 7.5 amp on the charging side and the supply side, both the fuses were intact. Now i'm left wondering why mine had been fine and his wasn't despite being exactly same batteries with everything pretty much the same.

I got the battery via trade account I have and they are going to talk with the manufacturers. It has put me off putting Li Ion batteries on anything now, that said I will continue to use one on my Lambretta and monitor it. I am beginning to think it's a faulty battery rather than a general issue.

That is what I was thinking about as Fast n Furious pointed its a bit near a lot of Fuel!

I'd post the photos / video of it smoking if it was easy to do.

It was the first time the battery had been fitted that it failed, probably within 40 miles or so.

I checked the battery on mine as soon as my pal rang and mine was still as good as new.

I am going back to a lead acid battery on his.

The better (much more expensive) Lithium ion batteries incorporate BMS (an electronic battery management system) which will shut down the supply when the battery is fully charged to prevent potential damage through overcharging
These batteries can not readily tolerate being charged by primitive magneto generators which have high levels of ripple current that can kill an unmanaged battery.
Modern motorbikes use alternators which have much better DC stabilty but should still use an integral BMS for optimum battery performance.

Fast n Furious wrote:The better (much more expensive) Lithium ion batteries incorporate BMS (an electronic battery management system) which will shut down the supply when the battery is fully charged to prevent potential damage through overcharging
These batteries can more readily tolerate being charged by primitive magneto generators which have high levels of ripple current that can kill an unmanaged battery.
Modern motorbikes use alternators which have much better DC stabilty but should still use an integral BMS for optimum battery performance.

I've just had a look on the companies website and apparently these batteries I use are really safe, providing the charge rate isn't about 15 volts. So a 5 pin Vespa regulator charges at like 4-5 volts. I'm stumped. I really hope they get back to me with an explanation.


https://www.skyrichbattery.com/p7/Lithi ... pages.html

Fast n Furious wrote:The better (much more expensive) Lithium ion batteries incorporate BMS (an electronic battery management system) which will shut down the supply when the battery is fully charged to prevent potential damage through overcharging
These batteries can more readily tolerate being charged by primitive magneto generators which have high levels of ripple current that can kill an unmanaged battery.
Modern motorbikes use alternators which have much better DC stabilty but should still use an integral BMS for optimum battery performance.

This is what I had in mind and it is fitted with a BMS so should be suitable if I check the input charge.

Thanks for everyones input on this
Clarkie
York