AC Charger Recommendations

[PNjunction]

I think Willy hit the nail on the head. CA has mandated to reduce their consumption to become more reliable on RE generation, so why not put a regulation requiring all electrical appliances to meet a higher efficiency standard.

Heh, part of that problem is that California's CEC thought it best to supersede the federal regulations / enforcement, and force manufacturers to either adopt California as the ultimate energy-czar, or create *multiple* versions of their product that follow both federal and California regs separately if they wanted to stay in business.

Despite many meetings from manufacturer engineers to find a common reasonable ground, it was all shot down. Manufacturers who don't want to spend their lifetimes in court, looked at the bottom line, and either just dropped out of business, or felt brow-beaten into following one state's standard along with the federal one.

Question is - who is the next state to set the regs over the feds, and force another round of retooling / manufacturing? I guess California is in charge now. Like collecting state specialty coins, I can't wait to add a Nebraska-specific charger to my collection.

The problem manufacturers have is not one of efficiency being a good thing, but one of trying to stay in the business game when the goalposts are constantly moved around. For some, the issue was not about efficiency, but a political power-play.

My feeling is that consumers in states other than California are now subsidizing the cost of retooling / manufacturing specially regulated chargers (and other gear...) so thanks!

Resistance is futile. All your chargers belong to us.

[inetdog]

At least some states which also feel that the Federal standards are too weak in a particular area are simply adopting CA standards instead of trying to write their own and putting the manufacturers into an even worse position of conflicting regulations.

Many states now specify that portable generators and other small engines meet the California Air Resource Board (CARB) standards. I have not tried counting them, but there do not appear to be any states that have chosen to go off on their own rather than follow either basic Federal or CARB standards.

[bcroe]

Resistance is futile. All your chargers belong to us.

I build my own chargers.

Its about time small engine technology moved ahead; till recently it had hardly changed in a century. They
probably only went to overhead valves after they started coming in from Asia. Just listening to them run
sounds bad. I was able to completely transform the performance & economy of my 20 hp tractor by
replacing the fixed spark timing with a computer mapped advance. Got the lawn mowed faster with less
gasoline. Probably helped emissions too. Bruce Roe

[PNjunction]

At least some states which also feel that the Federal standards are too weak in a particular area are simply adopting CA standards instead of trying to write their own and putting the manufacturers into an even worse position of conflicting regulations.

True - and the simplest way to do it is to just make the entire lineup adopt CA standards. But that is purely technical. The political power play can start to be ridiculous. What if San Francisco and Los Angeles decided to supersede the state regulations, with even more individually stringent requirements than Sacramento, and force resellers to only sell "city-approved" chargers?

Basically the CEC has the power to put the small guy, even if he was the most efficient on the planet, out of business if the goalposts change on a whim.

It is a slippery slope indeed.

[lkruper]

I build my own chargers.

Can you do this cheaper than off the shelf? Is it a simple rectifier charger? How clean does the DC power need to be?

[bcroe]

Can you do this cheaper than off the shelf? Is it a simple rectifier charger? How clean does the DC power need to be?

i have been accumulating surplus parts and building stuff a long time. So usually suitable
magnetics, rectifiers, and case can be found on a shelf. The important thing here is a good
match for the job. A rectifier off a straight transformer works. A series choke may improve
operation, seen some in exercise machines. My 60s charger uses a saturable reactor control.
Ferro resonant transformers work well, with current limiting and converting the incoming sine
wave to more of a square wave, best for a rectifier. I used SCRs to control them.

lately I've started to be concerned about efficiency, esp for a 24/7 maintainer. A large
tape wound core (very low standby loss) is supplying a few AC loads to eliminate the
standby losses of small control transformers (up to 5W each). Some rectifier windings
serve for some converted "battery" operated stuff (CO det, etc, etc), others for battery
maintainers. With the right control, the maintainer standby power is near zero. When
charging, a center tapped winding allows using a single rectifier drop in the loop instead
of 2 for a bridge. I think the next one will do the above plus allow using the car batteries
being maintained to supply my very small load of communication devices (antenna amp,
internet switch) for outages. Not designed yet.

Usually charging a battery doesn't need smooth DC; pulses will do. If you were charging
a telephone office 48V talking battery, you need smooth power. Those use 3
phase and the huge battery is a good filter. Bruce Roe

[lkruper]

i have been accumulating surplus parts and building stuff a long time. So usually suitable
magnetics, rectifiers, and case can be found on a shelf. The important thing here is a good
match for the job. A rectifier off a straight transformer works. A series choke may improve
operation, seen some in exercise machines. My 60s charger uses a saturable reactor control.
Ferro resonant transformers work well, with current limiting and converting the incoming sine
wave to more of a square wave, best for a rectifier. I used SCRs to control them.

lately I've started to be concerned about efficiency, esp for a 24/7 maintainer. A large
tape wound core (very low standby loss) is supplying a few AC loads to eliminate the
standby losses of small control transformers (up to 5W each). Some rectifier windings
serve for some converted "battery" operated stuff (CO det, etc, etc), others for battery
maintainers. With the right control, the maintainer standby power is near zero. When
charging, a center tapped winding allows using a single rectifier drop in the loop instead
of 2 for a bridge. I think the next one will do the above plus allow using the car batteries
being maintained to supply my very small load of communication devices (antenna amp,
internet switch) for outages. Not designed yet.

Usually charging a battery doesn't need smooth DC; pulses will do. If you were charging
a telephone office 48V talking battery, you need smooth power. Those use 3
phase and the huge battery is a good filter. Bruce Roe

I saw some DIY power supply descriptions and wondered about the efficiency. If you use a rectifier to remove all the negative does that mean your efficiency is automatically no better than 50%?

As for cost, I found a variable power supply online from some outfit in Arizona, I think, for about $79 that was 25 amp output and 0-30v (from memory). It would seem hard to beat that kind of price, but perhaps these cheap supplies don't last?

[bcroe]

I saw some DIY power supply descriptions and wondered about the efficiency. If you use a rectifier to remove all the negative does that mean your efficiency is automatically no better than 50%?

As for cost, I found a variable power supply online from some outfit in Arizona, I think, for about $79 that was 25 amp output and 0-30v (from memory). It would seem hard to beat that kind of price, but perhaps these cheap supplies don't last?

A rectifier not conducting DOES NOT use any energy, or cut efficiency in half. They are generally used
in alternating pairs to smooth things out.

With the high frequency switching technology now in use, the cost & weight of a supply can come
way down. Just look at the price on a 500 watt PC supply. So really my stuff is obsolete. But its
very cheap for me, and can be made very efficient, very reliable, and easily serviced. Bruce Roe

[Sunking]

Can you do this cheaper than off the shelf? Is it a simple rectifier charger? How clean does the DC power need to be?

It doesn't need to be clean at all, the batteries are the filter. DC filters are primarly done with big Filter Brute Force Capacitor. A battery makes a filter capacitor look like a small child up against a pro football player.

Unless you have access to salvaged parts, the transformer is the biggie, no way can you build cheaper than buying. The transformer is the deal breaker. However if one knows what they are doing, I can charge anything with a Salvage PC Power Supply and a Hobby Charger. I hate uni-taskers. I have a charger that can charge any battery type of today and tomorrow with any algorithm up to 1300 watts of charge power. Only thing it cannot do is 48 volts/ 36 max. Can yours do that for less then $275.

[lkruper]

It doesn't need to be clean at all, the batteries are the filter. DC filters are primarly done with big Filter Brute Force Capacitor. A battery makes a filter capacitor look like a small child up against a pro football player.

Unless you have access to salvaged parts, the transformer is the biggie, no way can you build cheaper than buying. The transformer is the deal breaker. However if one knows what they are doing, I can charge anything with a Salvage PC Power Supply and a Hobby Charger. I hate uni-taskers. I have a charger that can charge any battery type of today and tomorrow with any algorithm up to 1300 watts of charge power. Only thing it cannot do is 48 volts/ 36 max. Can yours do that for less then $275.

No, the cheap ones were less power (1-30w, 25a) and then when I read the specs they could only run for up to 8 hours continuous. I know what you mean about the transformer, because that is what I noticed... the larger amp ones were $125 and up from reputable sources.

[bcroe]

No, the cheap ones were less power (1-30w, 25a) and then when I read the specs they could only run for up to 8 hours continuous. I know what you mean about the transformer, because that is what I noticed... the larger amp ones were $125 and up from reputable sources.

A lot of things are capable of a much longer duty cycle with some forced air cooling. I had to
add a couple modest fans to my MIG welder to get extended use (without thermal shutdown)
at the max setting.

The transformer charger can be built with a minimum level of expertise. Unfortunately the high
tech switching units need to be bought by most. I was trying to work out a way to convert used
microwave oven transformers, but the newest ones are too cheaply made to be used this way.

Bruce Roe