How to charge hand tool batteries in van

[SSHandyman]

2005 Dodge Sprinter 3500 dually
Montreal

 

[tx2sturgis]

Inverter 101:

A 300 watt pure sine wave inverter is what you want.

Expect to pay around $100 to $150 for a good one, but some bargains and clearance sales can be found. I would stay away from the cheap modified sine wave inverters. 

It will probably not power everything you have simultaneously, but will power 2 of them easily, and will not require a really heavy power cable.

 

[highdesertranger]

he my as well get one big enough to run the miter saw. yes pure sine is better for the chargers. for the larger draws only use when the engine is ruining. if it were me I would put a house battery in. highdesertranger

 

[tx2sturgis]

For the price of a large inverter, a house battery, place to put it, solar or solenoid or DC-DC charger, cables, etc etc, he can buy a nice generator in the 1800 to 2500 continuous range and power that large miter saw, and just about all the other normal 120v tools at a jobsite.

For handyman use it does not have to be an inverter generator...a normal contractor genset will be ok, and maybe perferable, for most of the intermittent use for that type of power saw.

 

[Weight]

The compound miter saw is not going to operate from any inverter on a starter battery, or the vehicle alternator. The hand tool batteries can be recharged from a small inverter (Sine Wave, not modified) I would use my watt meter to check what the charger needs as far as power and get the inverter to charge maybe two of them at once. You still don't have enough vehicle battery and need to plan on a house battery. Unless all your hand tools have the same battery and charger, the inverter is a good choice.

 

[SSHandyman]

The generator route is interesting for powering tools... but aren't they loud if I'm charging batteries? How would that work?

I am open to purchasing a battery and an inverter: 

My Sprinter is a new purchase and had been outfitted with a low guage wire already at the rear of the cargo area as shown in the photo...possibly for a lift. I have to check its size and status though. So if I buy a battery and hook it up there and connect it to a 3000W inverter, then it would give me charging capability as well as the use of any single power tool, right?

Again, dumb it down. I'm a newbie.

Thx

 

[highdesertranger]

I think we are confusing him more then anything. everybody here has given good advice but it's all over the place. I have helped add to the confusion. I think we all can agree that a small sine wave inverter would be enough to charge his tool batteries. he will just have to keep an eye on his starter battery. highdesertranger

 

[highdesertranger]

haha you got that one in while I was typing. highdesertranger

 

[frater secessus]

I am new to all this electrical stuff so please speak like Bob in his tutorials....like its an Inverter 101 course.

SCENE:  National Forest, approx. 4000'.   BOB stands in front of a picnic table with INVERTERS on it.

BOB:  "Welcome back to my.............. NEXT.....videohhhhh.  Today we will talk about inverters.  Very few people think about inverters, and that just makes the inverters sad.   Inverters work hard for us and we need to meet them where they are.  Bottom line is there's no reason to make MSW feel bad just because a few Dewalt chargers get hurt.  The inverter doesn't know any better;  that's its nature.  It's our job not to plug Dewalt chargers into them."

=== FIN===

First rule of Inverter Club:  don't use an inverter.   Srsly, though here's my version of Inverter 101.*








* but don't get an inverter

 

[tx2sturgis]

The generator route is interesting for powering tools... but aren't they loud if I'm charging batteries? How would that work?

 
300 watt inverter for the cordless tools.

If you find you need to fire up the big, loud, powerful saws and compressors, large battery charger, etc etc, then a genset can do that job.

No, dont use a large genset just to charge cordless tools.

 

[gypsyjoker]

Frater; thanks for the laugh and thanks for the link. Great info on there!

 

[bullfrog]

In a perfect world all your battery powered tools would run off the same battery and you would have several charged and ready. I like HDR converted all my tools to one battery style which was expensive, and bought an in vehicle charger which for me made it much easier to ensure I had tools that worked when I needed them to. I also installed a house battery. Most off grid set ups now use generators (propane seems to be the new choice as it does seem to not have as many maintenance issues with intermitent use and fuel storage) to run high load AC's, microwaves, as well as saws and mediun air compressors. An air compressor comes in handy for all sorts of tools, but this takes up a lot of space. You can make or buy a jig to use an 18 volt circle saw as a miter saw. I found I could most if not all jobs using 18 volt tools except for welding or breaking concrete, it just costs more to do it this way but takes up a lot less space which in the long run is my biggest problem. If I put in solar later on everything is 12 volt ready this way. How big of jobs you take on and where will be a big factor in what works for you.

 

[bamabradford]

As far as the dc charging thing goes, I use the Stanley 140 watt inverter. It has an ac outlets and a couple usb's. There is hardly any noticable drain on my batteries and it plugs into a cigarette outlet.
Anything above 140 watts needs to be connected straight to the battery so the Stanley Fatmax 140 watt inverter is the ticket for charging all sorts of batteries.

Got em for my sons and they love em. Idk the current prices but they should be under $25 @ walmart.com, EBay, Amazon ??
If they let you down you can throw rocks at me when ya see me. PEACE

 

[bamabradford]

 

[SSHandyman]

So to sum up...

To only charge tool batteries I just need a 12V DC to 120V inverter at about 300 to 500 Watts?

To charge both batteries AND a 1680 Watt miter saw, I need to buy a sealed battery and connect it to, say a 3000 Watt pure sine wave inverter?

Let me know what I may be missing here. Thanks.

 

[user 13167]

If you have a direct power line from the alternator it would give you a perfect buffer to protect your starting battery by adding a battery in the back.

You can add a solenoid or isolater so it will only charge when the engine is running.

I have five Dewalt batteries all the way up in size to the 6Ah and charge them all using an isolated battery and a $150 500w pure sine inverter I got from Renogy. I’m always amazed how fast these 20v batteries charge!

https://www.renogy.com/renogy-500w-12v-off-grid-pure-sine-wave-battery-inverter-w-cables/

 

[Weight]

What you are missing is how to size a battery to what you need for power. Example; the 1690 watt saw operating on an inverter needs at the very least 145 amps from the battery. You need enough battery to supply those amperes for as long as you run the saw. That will not happen easily on any battery.

 

[John61CT]

Batteries do not generate, only store power.

You really need to know how many AH you require while you have no charge source.

For running big power tools you need a genny, or maybe a big alt+big inverter can handle it. That then becomes an active charge source.

You need to learn the details, how to measure your actual needs with a decent ammeter before anyone can design a suitable and reliable system for you.

 

[SSHandyman]

ok. forget the use of power tools...too complicated. I'll charge my batteries and that will be the end of it.

So am I correct that I just use a 500W 12V DC to 120V inverter that plugs into the 12v outlet? I have 4 chargers that total 275W, plus will probably hook up a USB for my computer.

 

[user 13167]

That should work fine. Skip the power tools and you should be okay.

If you are not adding a separate battery you may want a fuse between the power and the inverter to control the max load on your alternator.

Best to position the inverter as close to the battery as possible for best performance.