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Small Cabin Forum / Off-Grid Living / 12v Inverter
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paulz
Member
# Posted: 16 Mar 2020 14:48
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I was just reading that the inverter I have should only be used with a lead battery. I was going to hook it to a Valence Lifepo4.

Is it bad for the battery or the inverter?

Nobadays
Member
# Posted: 16 Mar 2020 15:17
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That seems strange... unless it is an inverter/charge. Not all inverter/chargers can be set to properly charge a lithium battery.

But if it is just an inverter, I have a hard time seeing if the 12/24/48vdc you are feeding it with is on lead acid/lithium or any other battery chemistry.

Would love to know the why/if and how if this is true.

paulz
Member
# Posted: 16 Mar 2020 15:24
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I was going to buy this

https://sfbay.craigslist.org/pen/ele/d/mountain-view-renogy-1000w-pure-sine/709125091 6.html

And while I was price checking I saw this, that says lead only

https://www.harborfreight.com/2000-Watt-Continuous4000-Watt-Peak-Modified-Sine-Wave-P ower-Inverter-63429.html

Nobadays
Member
# Posted: 16 Mar 2020 16:07
Reply 


The Renogy is an inverter/charger so my guess it can't be used with lithium as the charger part of the package is not suitable for charging lithium.

HF.... yeah just wondering if their copy editors are skookum enough on battery technology to even have lithium enter their thoughts. I do find it funny that it says "not for marine use," then specifies a "marine deep cycle" battery! I really think that one would not know where it was getting it's power from.

That said, keep in mind, as you likely know, AC motors don't really like modified sine wave inverters. In addition I personally don't run sensitive electronics like our satellite internet off modified sine wave either. Motors... fridge, pumps, etc will usually run but will under perform and can over heat. YMMV

paulz
Member
# Posted: 17 Mar 2020 10:39
Reply 


Thanks Nob. Yeah I guess that is because of the charger part.

I did not know about the limitations of modified sine wave, inverters are a new thing to me, but I do now, did some reading, thanks for mentioning it. I have a 5,000 watt now I was planning to use for circular saw, angle grinder etc. in the shop instead of firing up the genny every time. I really should move into the Lithium tool world, just never been able to decide with all the manufacturer and voltage diffs.

Brettny
Member
# Posted: 18 Mar 2020 05:38
Reply 


For the price of that renogy your basicly paying for the inverter and getting the charger for free. It's cheap enough you could buy an AIMS 75a charger, there a bit over $200 IF I remember.

That inverter/charger would be perfect for my needs. To bad it's across the country.

Nobadays
Member
# Posted: 18 Mar 2020 09:19
Reply 


Your 5000 watt inverter could possibly run your equipment, it won't hurt to try it. My understanding is electric motors often won't even start... set there humming, unplug it and don't try again. If they do run the power is not a proper curve that these motors require so they can run hotter and you would likely shorten their life. All that said we have a little 400 watt modified sine wave inverter in our van and we have used it for years to run a small coffee grinder. You can hear the difference in the sound of the motor though on the occasion we take it with us traveling and plug it into an AC outlet.... really spins and runs smoothly.

I got started on Makita cordless tools years ago. A few years back I stepped up to the 18v tools. Now 2 drills, 1 impact, leaf blower and a handheld vacume. This spring I'm going to get a circular saw. IMHO the 18v.... which ever brand... is a good balance of weight and power/longevity. I've tried a 20v, forget the brand but at least that one felt overly heavy.

Steve_S
Member
# Posted: 18 Mar 2020 15:24
Reply 


Quickly, I'll tell ya, Renogy = KRAP ! avoid it at all costs... there are horror stories everywhere about the product, service sales & support.

Do NOT get suckered into a "Car Inverter" which is typically a low cost FET based Inverter and most often they are High Frequency because of it. HF Inverters are fine for light occasional use when nothing critical or sensitive is on them.

You want a Pure Sine Low Frequency Inverter !
The Harbour Freight one is a FET Based Mod Sine car inverter. One to avoid.

AIMS Inverter/ Chargers are manufactured by Sigineer. They are a respectable value line and AIMS being a VAR (Value Added Reseller) has slightly improved specs. Most have either a basic Lithium Support and the more advanced ones are more programable.

MPP-Solar (has USA offices & warehouses etc) has also come up the line very quickly with very reasonably priced solutions which people are having great success with. While most folks have aversions to more "all-in-one" systems, MPP has done the smart thing by making it so that all components can be removed, replaced or serviced, unlike many others. https://www.mppsolar.com/v3/

REFS:
High vs Low Frequency inversion

https://www.magnum-dimensions.com/knowledge/high-vs-low-frequency-inverters/inversion -methods-explained-high-frequency-vs-low

Sigineer main site: https://www.sigineer.com/

mj1angier
Member
# Posted: 19 Mar 2020 10:41
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I got this unit and have had it on line for about 3 months:
https://www.amazon.com/gp/product/B07PHPBMCG/ref=ppx_yo_dt_b_asin_title_o04_s01?ie=UT F8&psc=1

I used it to run cirular saw, table saw, ac, ....

It's hooked up to a 24v Lifepo4. It has worked great so far. It is a China product and directions were a little wonky but not bad. My Lifepo4 battery came from China too so I told them what charger make and they were able to give the setting for lol

paulz
Member
# Posted: 19 Mar 2020 11:04
Reply 


That looks good and good price.

This is what I have now, and plan to try some power tools today. I have some old saws and drills, no big loss.
0319200755a_HDR.jpg
0319200755a_HDR.jpg


Nobadays
Member
# Posted: 19 Mar 2020 11:38
Reply 


Maybe not the best inverter for running tools but I bet it will work! I don't think you will hurt your tools.... if they don't like the power this delivers, don't use that tool with it. I think you will know right away.

Brettny
Member
# Posted: 19 Mar 2020 13:38
Reply 


Most power tools womt care. There just brushes running around a shaft with some wire. Things with circuit boards may.

To easy the load on your system why not just run the generator for power tool use?

ICC
Member
# Posted: 19 Mar 2020 13:54
Reply 


If the tool has a series universal motor the motor will not mind. Most tools have these. But if it is a variable speed motor the electronics probably will not like the modified square wave power.

Other motorized devices (not a series universal motor type) will run hotter and that can cause a shorter life. The devices will also use more power than if they were beig run on pure sine wave power.

Many, but not all, tool battery chargers will nearly instantly burn out on modified sine wave.

Nobadays
Member
# Posted: 19 Mar 2020 14:30
Reply 


ICC.... Good to know about tool battery chargers. Thanks!

paulz
Member
# Posted: 19 Mar 2020 15:57
Reply 


Yeah, nice not to learn by mistake as usual. Well I got my inverter connected and cut a couple boards, seem to run fine, single speed saw. So a variable speed drill won't like it sounds like.

Brett, my regular MO is to fire up a genny but often it's just to cut one or two boards. Yeah, I should get a battery saw. Actually the friend that moved gave me an 18v lithium Milwaukee drill with battery and charger, works great. Maybe I'll find a saw to suit. But the inverter is good to have anyway for other stuff.

neckless
Member
# Posted: 19 Mar 2020 20:21
Reply 


if u have a 5amp motor usually takes three time amps as per what it says for start up

Brettny
Member
# Posted: 20 Mar 2020 11:02
Reply 


I have the good m18 7 1/4in saw. It's very handy but you won't frame a cabin with it nor will you rip 8' lumber. You absolutely need a 5.0ah battery or bigger for it. I bought a new worm drive for all the heavy work.

paulz
Member
# Posted: 20 Mar 2020 13:56
Reply 


I notice my inverter makes a big spark when I hook it up to a battery after it's been unhooked awhile, even though the switch is off. A capacitor inside? If I leave it hooked up will it drain the battery?

ICC
Member
# Posted: 20 Mar 2020 18:21
Reply 


Maybe. That is why I use a large DC rated circuit breaker between the battery and every inverter that I may leave connected to the battery. Switches on the inverter, if any, only turn off the control system. There is a chance there may be a drain when sitting there for a time even with the switches off.

Another good reason to own a decent clamp meter. You could then test to see if there is a parasitic drain. Any inverter with a remote control is likely to have a small parasitic drain.

Brettny
Member
# Posted: 21 Mar 2020 08:36
Reply 


Yes there's capacitors in inverters

paulz
Member
# Posted: 21 Mar 2020 09:35
Reply 


Thanks guys. Well my dingbat wife left her cell phone at the cabin yesterday, probably take a drive out there today to retrieve it. I'll put my DVM on amps and put it in series and check.

Good excuse to escape the shelter in place anyway, 20 minute country drive, no stop lights the whole way.

I did learn something yesterday when I ran a circular saw off the inverter. The group 24 deep cycle lead battery went down to 11 volts while the saw was running. It's hooked to a cheapo 100w HF solar system, gets an hour or two of sun on a good day but will charge the battery when I'm gone for a couple days. 11 volts was low enough to kick off the charge controller, which is hooked to the 3 LED lights that come in the kit, plus a USB powered radio and baby monitor charger I'm swimming in those lead batteries at the moment since we recently replaced them at the emergency radio repeater so I'm going to put two in parallel, which should keep the light on when running the inverter.

Keeping my 3 Valence lithiums for cabin use, at least till the leads die out.

I'm starting to use this new carport as a shop more and more, which means angle grinder, small drill press, sanders, soldering iron..stuff that just runs for a short period.

Nobadays
Member
# Posted: 21 Mar 2020 12:25
Reply 


If you can, find a place to put those solar panels where they can get more hours of sun. If you parallel two of your 12v deep cycles it will be highly unlikely you will be able to get them fully charged let alone go through the Absorption cycle that they need. I did the math on the two 226ah 6v batteries I had hooked up to a 245watt panel during the winter. It would have taken something like 14 hours to recharge after a planned 46a load through like 16 hr of no charging per day. Those little SCC just don't put too many amps through.

Brettny
Member
# Posted: 21 Mar 2020 14:16
Reply 


Group 24 batterys are just about the smallest flooded deep cycle battery you can get. Between there age and how many surge amps your pulling I'm not surprised your hitting the low voltage cut off. Your pulling +130a at 12v from the batterys, thats a lot of juice from a small battery. Add more to the bank if you have them laying around.

paulz
Member
# Posted: 22 Mar 2020 17:16
Reply 


Some progress. These two Caterpillar batteries ran my cabin until I got the Valence lithiums. They are old but I charged them a couple days ago and they held at 12.6. So I just put them in the carport, wired in parallel. I put a DVM on the inverter, almost 1 amp when turned on, then went to 0. Plugged in a variable speed drill to drill a hole, ran fine, voltage dropped to 12.2 but lights stayed on.

I moved my solar panels to the front of the roof of the carport, you can see them in the photo. Best sunlight I'm going to get.
0322200843a_HDR_resi.jpg
0322200843a_HDR_resi.jpg
0322201150_HDR.jpg
0322201150_HDR.jpg


Nobadays
Member
# Posted: 22 Mar 2020 17:31
Reply 


Beautiful location but yeah... tough place for solar

Brettny
Member
# Posted: 23 Mar 2020 07:03
Reply 


You can still use them to store power so you don't have to hear the generator run all day/night

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