I need some advice on building a battery charger for my bank of 20 Li-ion 5000mAh 26650A

[sheffieldyorky]

You can get a new clone of a Honda GX series engine on ebay for less that £100.

Pardon our interruption...

Rig up a base for the setup and run a small three terminal alternator with a belt drive and a big pulley on the engine, and use a 12V deep cycle / leisure battery for the power storage.

Even at eg. 100A at 15V from the alternator, that would only be 1500W or around 2hp; the engine would running at quite light load.

I've worked on one of those engines, they are pretty good, with an easy-starting system.

Hi there
Many thanks for your response, seems like a plan. £99.99 is well worth the price.
So utilising what I already have but have not used and coupling it onto the following

• Drive Shaft Diameter: 20mm / 0.786inch
• Length of Drive Shaft :50mm/1.97inch
• Keyway Diameter: 4.8mm

Also, I have just noticed "Engine rotation Anti clockwise"
What size O.D. pulley wheel do I need I will then couple up to my three terminal alternator this is to get the correct ratio to speed correct. I then need somehow to get to my inverter

 

[rjenkinsgb]

Looking at the typical speed range of that series of engines, probably somewhere around the same diameter as a car crankshaft pulley, or a bit smaller; in the 4" to 6" range at a guess?

Honda Engines | GX120 4-Stroke Engine | Features, Specs, and Model Info

Official specs and features for the Honda GX120 small engine. The GX120 is a small four-stroke gas engine offering superior performance and reliability.

engines.honda.com

Possibly??

SPA 125 - 1 T/L, Taperlock V-Belt Pulley | Bearing Revolution

SPA 125 - 1 T/L, Taperlock V-Belt Pulley Available To Purchase Online From Bearing Revolution, The SPA 125 - 1 T/L, Taperlock V-Belt Pulley Is Available At Competitive Prices And Available From All Major Brands (Premium Range). Visit Us Online To Purchase SPA 125 - 1 T/L, Taperlock V-Belt Pulley...

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plus

1610-20 (mm) Taper Lock Bush

1610-20 (mm) Taper Lock Bush

bepltd.com

and the appropriate key.

 

[sheffieldyorky]

Looking at the typical speed range of that series of engines, probably somewhere around the same diameter as a car crankshaft pulley, or a bit smaller; in the 4" to 6" range at a guess?

Honda Engines | GX120 4-Stroke Engine | Features, Specs, and Model Info

Official specs and features for the Honda GX120 small engine. The GX120 is a small four-stroke gas engine offering superior performance and reliability.

engines.honda.com

Possibly??

SPA 125 - 1 T/L, Taperlock V-Belt Pulley | Bearing Revolution

SPA 125 - 1 T/L, Taperlock V-Belt Pulley Available To Purchase Online From Bearing Revolution, The SPA 125 - 1 T/L, Taperlock V-Belt Pulley Is Available At Competitive Prices And Available From All Major Brands (Premium Range). Visit Us Online To Purchase SPA 125 - 1 T/L, Taperlock V-Belt Pulley...

www.bearingrevolution.co.uk

plus

1610-20 (mm) Taper Lock Bush

1610-20 (mm) Taper Lock Bush

bepltd.com

and the appropriate key.

Many thanks for that, I will start looking around.
Three questions for you;
1) As you already have substantial knowledge of working on/with these, despite exhaust fumes is it quiet enough to run in my outside workshop detached from the house ?
2) "Engine rotation Anti clockwise" will this cause a problem going forward ?
3) Will I be correct in thinking the following;
a) Honda engine charges the "Leisure battery"
b) A fully charged Leisure battery now supplies the Pure sine wave inverter
c) Inverter now supplies my 1200w appliance
d) When leisure battery drops below a certain amount (TBA)
e) I fire up the Honda engine and start again from item a) above

If my thinking of a,b,c,d & e are correct can you recommend somewhere where I can obtain a schematic for a Pure sine Wave Inverter 1200w minimum ?
I have seen several on YouTube but for one reason or another, I pass onto the next one.

 

[Nigel Goodwin]

If my thinking of a,b,c,d & e are correct can you recommend somewhere where I can obtain a schematic for a Pure sine Wave Inverter 1200w minimum ?
I have seen several on YouTube but for one reason or another, I pass onto the next one.

Buy one, you're unlikely to be able to make a reliable one, and the parts will cost more then buying a commercially made one.

 

[sheffieldyorky]

Buy one, you're unlikely to be able to make a reliable one, and the parts will cost more then buying a commercially made one.

Hi Nigel
Many thanks for your response.
As previously written by me "With regards to electronics, I am happily working at the computer component level and all that it entails." If I have a verified schematic that works, I am somewhat puzzled about being unlikely to be able to make a reliable one.
If you look at a motherboard on either a desktop or even a laptop, I am more than capable of repairing them. My knowledge goes down to the component level, I am not going to go into the ramifications of inserting items the wrong way around, soldering dry joints etc. I have more respect for you than that but suffice it to say, I run a laptop repair business and I have not had a laptop/desktop beat me yet.
So if Joe-Bloggs inverter company builds and sells inverters of various wattage outputs and with a favourable Trust Pilot review and I get/obtain one of their schematics 1200w minimum then who am I to call into question their validity.
Thanks anyway Nigel.

 

[Nigel Goodwin]

Hi Nigel
Many thanks for your response.
As previously written by me "With regards to electronics, I am happily working at the computer component level and all that it entails." If I have a verified schematic that works, I am somewhat puzzled about being unlikely to be able to make a reliable one.
If you look at a motherboard on either a desktop or even a laptop, I am more than capable of repairing them. My knowledge goes down to the component level, I am not going to go into the ramifications of inserting items the wrong way around, soldering dry joints etc. I have more respect for you than that but suffice it to say, I run a laptop repair business and I have not had a laptop/desktop beat me yet.
So if Joe-Bloggs inverter company builds and sells inverters of various wattage outputs and with a favourable Trust Pilot review and I get/obtain one of their schematics 1200w minimum then who am I to call into question their validity.
Thanks anyway Nigel.

Why pay (probably considerably) more?, and how do you plan getting hold of the custom transformers?, there's also quite likely to be custom software involved, many such designs are processor based.

 

[sheffieldyorky]

Why pay (probably considerably) more?, and how do you plan getting hold of the custom transformers?, there's also quite likely to be custom software involved, many such designs are processor based.

Hi there Nigel
To be honest that makes sense, i.e. "and custom transformers" and also "custom software", so now I need to look around for an applicable Pure Sine Wave Inverter company, do you use one or do you have any knowledge of a reputable supplier preferably U.K based I don't want to get into the import scenario etc.
Tony
P.S. Nigel, I have just been on your website and saw that you were having problems with Windows 2000, in my humble opinion stay well away from Windows 2000 it was never known as a good O.S, Windows 7 (support now finished) Windows 10 Version 21H (OS Build 19044.3086 is current and stable, move to Windows 11 at your own risk, I belong to Windows insider and get regular updates. Just thought that might help.
Tony

 

[Nigel Goodwin]

Hi there Nigel
To be honest that makes sense, i.e. "and custom transformers" and also "custom software", so now I need to look around for an applicable Pure Sine Wave Inverter company, do you use one or do you have any knowledge of a reputable supplier preferably U.K based I don't want to get into the import scenario etc.
Tony

I've never used one, so have no idea of source or quality.

P.S. Nigel, I have just been on your website and saw that you were having problems with Windows 2000, in my humble opinion stay well away from Windows 2000 it was never known as a good O.S, Windows 7 (support now finished) Windows 10 Version 21H (OS Build 19044.3086 is current and stable, move to Windows 11 at your own risk, I belong to Windows insider and get regular updates. Just thought that might help.
Tony

That was long ago, the days of parallel port PIC programmers are long gone

Anything after Win3.1 was NT based, and no longer allowed direct access to the ports.

 

[rjenkinsgb]

Engine rotation direction is irrelevant to an alternator

Noise wise, they are a typical lawnmower or garden cultivator style engine. You could add some sound baffles if you wanted it a bit quieter.

The alternator has internal regulation so the engine load will drop off and the engine run light at the governed speed, once the battery reaches full charge. It can run just as well with or without the inverter load connected.

What appliance are you trying to run? Most things that use a switched mode PSU or rectifier input will work on any waveform, or even DC!

If my thinking of a,b,c,d & e are correct can you recommend somewhere where I can obtain a schematic for a Pure sine Wave Inverter 1200w minimum ?

As Nigel says - buy one.

There are some things that it's simply impossible to do one off or small volume build at the cost and reliability of commercial retail products. I've been designing electronics for 40+ years, and certain types of device are just not worth the time, cost and effort when commercial parts can do the job.

High wattage switched mode power systems are one of those. Just a one-off set of the required custom wound transformers and inductors typically costs more than a ready-built unit.
Plus it generally takes quite a few prototypes to get the whole design working as intended.

Have a look at such as these:

Photonic Universe - 1500W 12V Pure Sine Wave Power Inverter with On/Off Remote Control

Photonic Universe 1500W 12V Pure Sine Wave Power Inverter Continuous Power - 1500W Surge Power - 3000W Input - 12V DC Output - 230-240V AC

www.splitcharge.co.uk

 

[sheffieldyorky]

Engine rotation direction is irrelevant to an alternator

Noise wise, they are a typical lawnmower or garden cultivator style engine. You could add some sound baffles if you wanted it a bit quieter.

The alternator has internal regulation so the engine load will drop off and the engine run light at the governed speed, once the battery reaches full charge. It can run just as well with or without the inverter load connected.

What appliance are you trying to run? Most things that use a switched mode PSU or rectifier input will work on any waveform, or even DC!



As Nigel says - buy one.

There are some things that it's simply impossible to do one off or small volume build at the cost and reliability of commercial retail products. I've been designing electronics for 40+ years, and certain types of device are just not worth the time, cost and effort when commercial parts can do the job.

High wattage switched mode power systems are one of those. Just a one-off set of the required custom wound transformers and inductors typically costs more than a ready-built unit.
Plus it generally takes quite a few prototypes to get the whole design working as intended.

Have a look at such as these:

Photonic Universe - 1500W 12V Pure Sine Wave Power Inverter with On/Off Remote Control

Photonic Universe 1500W 12V Pure Sine Wave Power Inverter Continuous Power - 1500W Surge Power - 3000W Input - 12V DC Output - 230-240V AC

www.splitcharge.co.uk

Hi there

Many thanks for your response.

I will address the points raised.

Engine rotation direction is irrelevant to an alternator

Noted, I have only ever dealt with vehicle alternators, including changing rectifier packs etc.



Noise wise, they are a typical lawnmower

Noted. It will be going in my outside workshop.



sound baffles

I will judge it at the time but it will only be running to charge up the leisure battery.



What appliance are you trying to run? Most things that use a switched mode PSU or rectifier input will work on any waveform or even DC!



UNIT 1) the maximum power would be 1200w required by my inverter.

Toshiba 900w 23L Microwave Oven with 1050w Crispy Grill,

PANASONIC TX-32JS360B 32 TV 31w

UNIT 2) the minimum power would be 800w required by my inverter.

My self-built desktop

Areocool Integrator 500w P.S.U

Dell P2414H Full HD 1920x1080p 23.8" Monitor, 28w

Workstation, c/w iron, heat gun etc. 1320w but only used occasionally

Total 528w, running peak 600w

So as you can see no initial surge is required for motors except desktop fans, and one fan in the workstation.

Once I am sorted I fully intend to build a little 30mA RCD-controlled two-way consumer unit c/w 1 x 6a mcb & 1x 16a mcb.

This is exactly what I want “Photonic Universe – 1500W 12V Pure Sine Wave Power Inverter”

This does away with the consumer unit which is an added expense.

 

[Nigel Goodwin]

UNIT 1) the maximum power would be 1200w required by my inverter.

Toshiba 900w 23L Microwave Oven with 1050w Crispy Grill,

That would be 1950W then if you use it in dual mode, 900W is also likely to be the power output of the magnetron, the power input will be a good bit higher.

I used to use a 2kw generator for emergency power, it happily ran a 650W microwave, and a light or two. Power consumption on a 650W microwave is about 1000W.

 

[sheffieldyorky]

That would be 1950W then if you use it in dual mode, 900W is also likely to be the power output of the magnetron, the power input will be a good bit higher.

I used to use a 2kw generator for emergency power, it happily ran a 650W microwave, and a light or two. Power consumption on a 650W microwave is about 1000W.

Hi there Nigel
So my Unit 1 will do the trick @ 1200w
As you can imagine the microwave only runs for 3 mins max no longer.
Microwave is only used twice a day 3 minutes midday & 2 minutes late afternoon.
I could then plug the kettle in @ 1500w but not at the same time, the kettle is used throughout the day.
Can you think of somewhere that I can part recoup my losses on the two unused Stepper motors, I know that I am going to have to take a hit, but C'est la vie

 

[sheffieldyorky]

It looks like we have my problem sorted at last
Now moving on to leisure batteries ( I'm binning the idea of using my already purchased Li-ion 5000mAh 26650A batteries.
I have no knowledge of leisure batteries except the caravan/RV people use them and they cost way more than vehicle batteries.
Based on the above thread what are your suggestions

 

[rjenkinsgb]

Look at deep cycle batteries intended for such as electric golf buggies; those should be types that can stand fairly high discharge currents, as well as having a good overall cycle life.

eg. this type of thing may work.

Fuller Powertrak Deep Cycle Leisure Battery 125Ah 12V | County Battery

Deep cycle leisure battery from Fuller Battery, providing applications with more power for longer-lasting results, shop online with County Battery today.

www.countybattery.co.uk

The inverter will need over 100A to give 1200W output, so the battery must be for such as motorised vehicles, rather than just low current loads.

You may be better off with two batteries in parallel to reduce the maximum current from each battery - or run the generator while the microwave is on.

One of those batteries would give less than an hour at 1200W load, possibly 2hrs at 500W.
Also, high current charging and discharging reduces their life.

(Though they are very good in comparison to a car starter battery - it only takes around half a dozen full discharge cycles to wreck one of those. The difference is they can stand several hundred amps repetitively for years, as long as the percentage discharge is minimal).

 

[Nigel Goodwin]

It would also be a good idea to use a 24V inverter and a 24V leisure battery, or two (identical) 12V ones in series, as this obviously halves the current.

 

[sheffieldyorky]

It would also be a good idea to use a 24V inverter and a 24V leisure battery, or two (identical) 12V ones in series, as this obviously halves the current.

Hi there Nigel
Can you please explain your reasoning behind this "24V inverter and a 24V leisure battery" , I will only be using this for the above items in the thread.

 

[Nigel Goodwin]

Hi there Nigel
Can you please explain your reasoning behind this "24V inverter and a 24V leisure battery" , I will only be using this for the above items in the thread.

Simple maths, a 12V system will take 100+A from the battery, a 24V system will take 'only' 50+amps from the battery - so will last twice as long, and allow the use of thinner wires. It's why lorries use 24V systems and not 12V - and why cars long ago moved from 6V to 12V.

There's been talk of car systems moving to 36V or even 48V, perhaps some have?.

 

[sheffieldyorky]

Simple maths, a 12V system will take 100+A from the battery, a 24V system will take 'only' 50+amps from the battery - so will last twice as long, and allow the use of thinner wires. It's why lorries use 24V systems and not 12V - and why cars long ago moved from 6V to 12V.

There's been talk of car systems moving to 36V or even 48V, perhaps some have?.

Hi there Nigel
Well, I have to say, you live & learn, I never knew that.
In my career, I dealt with 415v, 230v, 110v and extra low voltage, stuff used in some CCTV installations, access control, barriers etc.etc.
I never came across any 24v systems/requirements, but as I commonly say "it is a sad day when I don't learn something new"and I'm 76 years old and still learning.
So with that said many thanks, Nigel

 

[sheffieldyorky]

Electrical Installations Part 8
Just checked on current IEE Regulations Section 8.8 – Lighting
8.8.1 A final sub-circuit of rating exceeding 16A is not to supply more than one point. The number of lighting points supplied by a final sub-circuit of rating 16A or less is not to exceed the following
24v circuits 10
110v circuits 14
230v circuits 18
except that in final sub-circuits where lamp holders are closely grouped, the number of points supplied is unrestricted provided the maximum operating current in the sub-circuit does not exceed 10A

 

[rjenkinsgb]

The generator and battery side is not part of the "Electrical installation" as covered by regulations.
It's more akin to vehicle wiring - and many large vehicles use 24V systems.

It's a good idea, the battery life will be rather better and the cable losses lower.

See this for an example of a vehicle fuse ratings - there are quite a few 40 - 50 - 60A ones in the general fuseboxes & far higher than that in the battery distribution box!

https://www.fordservicecontent.com/Ford_Content/vdirsnet/OwnerManual/Home/Content?variantid=7803&languageCode=en&countryCode=USA&Uid=G2178619&ProcUid=G2178620&userMarket=usa&div=f&vFilteringEnabled=False&buildtype=web

edit - forgot the link!