How to charge hand tool batteries in van

[Ticklebellly]

I really like that you used the term 'stepped square wave'.

Marketing conventions ........................

But, having said that, chargers will sometimes run a lot warmer on a stepped square wave input. 

No one makes a pure sine wave inverter, then modifies the shape of the output.   As a former editor and writer of technical documents, the use of poor descriptive terminology grates.    Marketing?   I think the less technical folk look for the "Sine wave" term, then the price, then decide if "modified" should have much bearing on their decisions.

Have not investigated or noticed temp differences associated with input technology but can think of a couple of reasons for the effect.   The effect may be a reason to ensure your charger has a fan?

I really only got involved in the discussion to object to extreme and misleading statements about MSW inverters "eating" chargers.

 

[Ticklebellly]

Would be interesting to look inside the 12 Volt Ryobi chargers for their Ryobi One range. The device weighs about the case weight more than the Buck Boost converters available online from China for a couple of dollars. Even more interesting to put an Oscilloscope on the output. These Buck Boost converters are a current interest as I just received one to put on the end of a computer power supply to charge a small capacity LiFePo4 battery. The LiFePo4 battery is to replace the Nicads that once powered a cheapie hand drill.

 

[tx2sturgis]

 Even more interesting to put an Oscilloscope on the output.   

I happen to have a 'scope...from back when I was building, troubleshooting, and repairing repeaters.

I thought about making a video showing the output waveforms, but there are so many of those (boring!) videos already on youtube you can't count them.

Maybe just a few pictures of the screen, posted here, would suffice?

 

[highdesertranger]

here's my dealing with a DeWalt AC charger on a MSW invertor. yes the charger got hot and yes it took a long time to charge the batteries. in fact on one particular hot day it got so hot it scared me. I went straight down and bought a 12v DC charger and it works great. only gets warm and charges the batteries super fast as compared to the MS invertor. YMMV. highdesertranger

 

[tx2sturgis]

Another vote for pure sine.

Have any of you ever run a microwave on a MSW inverter? They make a very noticeable BUZZ and throw off more heat from the cabinet, and take longer to heat the food. 

I dont think they will catch fire, but it cant be good for the electronics.

 

[Ticklebellly]

Maybe just a few pictures of the screen, posted here, would suffice?

I think so.   The caveat is that not all devices put out the same.   I have seen MSW outputs that had 4 steps per quarter cycle and one that had 8 steps per quarter cycle.   A stepped square wave output better approximates a Sine Wave the more steps are included in a quarter cycle.   The 8 step device could even drive a pedestal fan without too much heat build up or much growling.   A bit of RC on the output to round off the steps also seems to help.

 

[Ticklebellly]

Have any of you ever run a microwave on a MSW inverter?

No, never tried and would not.   Never had a MSW inverter big enough, either.   Any thoughts on what problems might be with the MSW input?   Klystrons don't like ripple, so again, would be interesting to see the waveform applied.

 

[Ticklebellly]

here's my dealing with a DeWalt AC charger on a MSW invertor.  yes the charger got hot and yes it took a long time to charge the batteries.  in fact on one particular hot day it got so hot it scared me.  I went straight down and bought a 12v DC charger and it works great.  only gets warm and charges the batteries super fast as compared to the MS invertor.  YMMV.  highdesertranger

A few variables there.   I have chargers that get quite hot charging really low LiIon, and that is on mains power.   Did you ever try the first charger on a PSW inverter or mains, charging a battery at the same depth of discharge?  I'm just interested in info that would come from a comparison.

 

[tx2sturgis]

No, never tried and would not.   Never had a MSW inverter big enough, either.   Any thoughts on what problems might be with the MSW input?   Klystrons don't like ripple, so again, would be interesting to see the waveform applied.

What are you doing with a klystron?

Maybe you changed out a magnetron for super high power microwaves? Where do you put that thing, in a trailer?

:huh:

 

[highdesertranger]

I have used it plugged in to the grid. it would get warm but it never got hot. I also used it plugged into a Honda 2000i same thing got warm but not hot. highdesertranger

 

[Ticklebellly]

I have used it plugged in to the grid.  it would get warm but it never got hot.  I also used it plugged into a Honda 2000i same thing got warm but not hot. highdesertranger

Thnxs.   Going to do a couple of experiments.

I am wondering now if most of the 12 Volt chargers are based on the Buck Boost type modules I mentioned earlier.   I do have a Ryobi mains charger to try running off a MSW inverter I borrowed from a friend.   Just curious now.

 

[John61CT]

For those not experimenting, the Ryobi One+ battery system is fantastic, as is their 12V car charger - which is the way to go, no inverter at all is best.

Their new / coming very high capacity Lithium batts will be very useful for portable power storage, for lights, fans, general House use.

I'm thinking to capture folding solar panel output away from the van when you prefer to park in the cool shade.