Inverter has a Spark with Battery Connection

When you connect an inverter to a battery the capacitors inside the inverter charge very quickly and this causes a spark at the battery terminal. To prevent this spark from connecting batteries to an inverter all you need is a simple resistor. A 25w 30 ohm resistor can slowly charge the capacitors and prevent the spark.
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[@Goodie247]

Great video and straight to the point!

[@coldspring22]

Instead of resistor, I use regular incadescent light bulb (which is no more use as light bulb anyway due to inefficiency). Seem to work fine.

[@beats8498]

Thank you for the clear, cut and dry explanation!

[@ToolsTechAndGear]

Happy to help. This is a simple solution to fix the spark.

[@FamilyMelton]

Thank you. This was super helpful. I bought one of those resisters and it prevented that huge spark in my 24v system. Appreciate the video!

[@jllaine]

Well done and excellent safety point.

[@ToolsTechAndGear]

Using the resistor is much better.

[@brownyysnoopy]

Use a 12 volt automotive lightbulb used in older cars..you get a visual aid when it stop glowing the caps are charged..i even have a 48 volt bulb for my 48 volt inverters..

[@a787fxr]

That's a great tip! Any time I see sparks I don't like it. !:- )

[@ToolsTechAndGear]

Yes indeed! Sparks are bad unless you are trying to start a fire.

[@3ringmike-uk3xv]

Pencil sharp on both ends works. It’s all I had but it worked

[@vicentecarrasco3653]

I always use some kind of switches or breakers to avoid the sparks on the terminals.

[@leonshao888]

This one sounds better.

[@greggsteven1028]

thanks you answered my question.

[@PatrickBaptist]

I have a ruined 2kw inverter and before I send it back to amazon I thought I'd have some fun with it, you think it would be better to send 240VAC through the 12VDC side or through the 120VAC side of that inverter? I'm thinking the battery lugs want the 240, Ill hard wire it straight to a 20 amp double pole, you think it will make a big spark or 2? Def will hook up a meter and see what the output will be if anything.

[@hayderalsalman7984]

Very nice and more safe

[@ToolsTechAndGear]

Much better than sending a spark!

[@ff-mu6cc]

Thanks sir!

[@colpip3281]

Thanks!

[@todamnbad]

I have mine inside an old pill bottle, soldered the ends to bolts, drilled holes in the lid and bottom, put bolts through holes, added nuts. no more breaking of wires

[@cholter11]

Any suggestion for size of resistor for a 5000 watt inverter ? Perhaps use mistook smaller resistors ? Thanks for the update

[@richardbergin]

Kind of weird this is the first time hearing this tip but you've solved an issue for me

[@ToolsTechAndGear]

A switch or breaker is probably the best solution but using a resistor to slow charge those caps is a good option.

[@MyChannel-vm6dw]

Ive also heard that you should hook up same resistor yo the battery cut off switch. Is this true or necessary?

[@premitive1]

great tip

[@ToolsTechAndGear]

Thank you. It can save batteries from being damaged.

[@JustaCuriousity]

Hi, im going to replace an 10kva UPS batteries tomorrow, i am told that theres gonna be 30 pcs of 12v 7ah each. Do i need a bigger resistor or the one you used will be fine? Thank you very much.

[@helpmeretiresoon5972]

It should be here in 2 days. Im getting a 48volt inverter 2500watt off amazon and a 60 amp Hqst charge controller. I still need to find a way to get a 48 volt battery. The 50 amp 48 volt is 629 dollars on Amazon or i want to get a server rack. Battery 48 volt 100 amp. Im building this for van life eventually. The server rack batty is 1500 bucks way out of my price range right now. You know rent and bills.

[@popatop75]

maybe dumb question but would it still spark if i put the red wire on first? and what size wire should this be if i were to hook up a 1000 watt ot 1500 appliance microwave or drill thanks for the lesson

[@rodneyalberta2020]

this works on all batteris like gel

[@ajpepe72]

If using a lifepo4 battery can’t I just turn the battery discharge off in the bms app while making the connections ?

[@thegentlemen740]

What size resistor would you use for a 96v 580 amp battery?

[@user-de6kh6uu2x]

Does the same resistor work with a 4000w inverter and a 12v battery?

[@daz.r1994]

I just orderd a 25w 1 Ohm will this be ok to use as i have just seen this video. You have 25w 30 Ohm.

[@andrepentz3179]

Thanks that helped a lot. May I ask what size resistor do one need for a 24v inverter connecting to two 150ah batteries?

[@ToolsTechAndGear]

The same type resistor is going to work just fine for a 24v. I have used this on a 48v battery and there is no issues.

[@KwasiDapaah-hh1kz]

Please after doing this will you still need a fuse?

[@nabster4320]

One question please. We have load shedding(Scheduled) in my country(South Africa) & I bought a 2000w inverter & the battery for my home. So I would like to know what is going to happen if electricity comes back while the inverter is running(main switch not switched off? Will there be any damages when they both meet?

[@WizzRacing]

It takes time for an inverter capacitors to discharge. Once they are in use. If you disconnect one. It will take hours or days to totally discharge..So it's nothing to worry about. Unless the power is off for a few days..

[@OhMyElectric]

breaker is the best one to put

[@suriyashimrithchand6303]

But you always supposed to connect your positive first so when you put in ur negative n it sparks it will ground out everything

[@martinaka9585]

Thanks for the tip 🙏🏾

[@mrs.vandebilt]

Would you get a spark every time you switch on the inverter (having the wires connected all the time) or only when you first connect the wires from the inverter to the battery?

[@danstrayer111]

just the first time, once capacitors are charged it wont do that

[@paulfarrell1976]

A pencil works too, try it and do an update video :-)

[@brandonstitt8032]

Just doing it without registering at initial set up doesn't hurt anything thou right. I mean why somone would do it on daily basis. Other then unexpected spark no harms done to either units

[@ToolsTechAndGear]

Its possible to destroy an inverter with a single spark. The blue inverter that I had does not work anymore because of this. (But I did demo at least 10 times)

[@joecook4451]

@@ToolsTechAndGear thank you for this tip!! i just ordered a 150 amp breaker thinking thats what i needed, then i saw this. i got a 1200 watt innverter /charger and it broke 2 of them. it sparked at terminals and a spark instide the inverter. so by the second inverterr i figured there must be another needed step. the 100ah lithium with bms is still working thank god.

[@darlingtonekoh-ordan3257]

Introducing a DC Breaker also eliminates this issue

[@ToolsTechAndGear]

That is a good point. For testing the resistor is a good idea. for a full install a breaker is best.

[@panospapadimitriou3498]

wish i could save my brothers car tacho and rpms on dash . they burned.!! thankfully temp and fuel are still ok!!!!!

[@ToolsTechAndGear]

Sorry to hear that! Sounds terrible.

[@MuslimahBuilder]

I thought you connect Positive then Negative when connecting batteries, and disconnect Negative then Positive

[@auggiebendoggy]

My 2000 watt renogy sparked like a sparkler on the 4th of july. Or maybe a welder would be a closer analogy. Anyways, thanks for this vid.

[@ToolsTechAndGear]

The larger the inverter the larger the spark. A resistor is a good way to prevent that. A switch or breaker is another good way to stop the spark.

[@auggiebendoggy]

@@ToolsTechAndGear purchased a resistor and learned to precharge. Thanks so much!

[@laryangel4082]

Rrt