Jason Lee

I guess if you had the motor laying around and had something to mount it to and could rig up a fuel tank and everything associated with it then that would be an option.  But otherwise you would be miles ahead just buying a generator.  You can get a 2000W generator for only a few bucks more.

Eric Hanson wrote:I agree with your wife that Lithium-Ion batteries are not practical, pragmatic or cost-effective for an off-grid home.  Lithium-ion batteries, despite all the hype, are really niche performers, excelling in applications that require high power and energy densities in a small, light package.  These are just about perfect for laptop computers and power tools.  They would be great for Electric Vehicles if it were not for their high cost and limited charge-discharge cycles.  But a fixed application like a home requires neither a particularly high power or energy density.  Old, heavy, reliable batteries will do just fine.

Perhaps the best type of battery for your particular application is the Lithium Iron Phosphate (LIPO) battery.  These are a far cry from the better known Lithium Ion battery.  LIPO batteries are pretty light, have medium power and energy density, can be fully discharged and have something like 10,000 charge-discharge cycles, making them a long-term battery.  They are not cheap, but they are very reliable and don't have any of the stability (read as flammable and explosive) issues that Lithium-ion batteries do.  Also, standard battery charging electronics generally work just fine with them.

I am glad to see someone understanding the distinction between Lithium Ion and Lithium Iron Phosphate!  Most people have no clue.

However, Lithium Iron Phosphate (LiFePO4) is abbreviated LFP not LIPO.  LIPO is lithium polymer and is a VERY different animal.  LFP is the one you want for off grid energy storage.  I am selling tons of them to RV, boat, and golf cart owners in addition to off-grid solar applications.

It can be very difficult to find someone that is good with off grid solar.  Almost everyone you find online is going to be a grid-tied solar installer, which is a completely different beast.

I have a company called JRL Solar in the DFW area that does off grid solar only.  I have done several RV's and numerous off grid solar installations.  I am getting ready to do a big one for a guy for his well pump on his rural retreat.  I don't travel very far but if you want some help or advice, I'm happy to help.

Sorry.  I end up having to deal with people in my business that take misinformation like this on the internet and end up destroying their batteries or worse.  I have edited the post to be a bit less negative.  Thank you.

Fortunately, lithium batteries that are purpose-built 12V battery packs are 1) generally LiFePO4 which will not explode or catch fire and 2) have built-in battery management systems (BMS) that will prevent them from being overcharged and damaged.  

But you are absolutely correct - battery chargers are designed for one chemistry only unless you have a "smart" charger that can change settings to different profiles.  Even then, these types of chargers typically have very generic settings that are not optimal for a specific battery.  For example, many chargers with "lithium" charge profiles use 14.4V as the charging voltage.  This is safe and can be used across the board on different lithium chemistries.  However, it will not 100% charge the batteries that I sell from MillerTech or my own brand, Jericho Battery Company.  These require 14.5-14.6V to fully charge.

So making a blanket statement like "A 12v charger can charge any 12v battery" can be very dangerous to the uninformed who may destroy an expensive battery, start a fire, or never get the full capacity out of their battery because they followed ambiguous or misleading advice.

I have quite a bit of experience with lithium batteries, including owning my own lithium battery company.  All companies, whether in the States or elsewhere, buy their cells and BMS boards and components from China.  That is just the way it is.  So you can obviously get really high quality products from there and really cheap, gimmicky products, too.  That is why several people have stated that you have to test first and that many Youtubers have mixed results.

The adage that you get what you pay for applies here.  Even the worst lithium cells will outlast all but the best lead acid cells and outperform them.  That comparison is fairly easy to make on a performance and life cycle level.  Cost in the long run is debatable and one I get into quite frequently with people who are either really for or really against one or the other (I defend both types).  But the problems come when you try to compare lithium to other lithium batteries.  There are numerous Lithium Ion chemistries, including LFP or LiFePO4, and they are all different.  Then you have Grade A cells and Grade B cells and other grades.  And there are no standardized methods for testing.  Some companies charge and discharge on a 1C rate while others may use a 0.5 or 0.333C rate.

So like I said, just go with the get what you pay for theme and do the best you can.  Ask questions and if you don't get answers move on.  I try to be completely transparent and open with all the data on my batteries including how they are tested and where they are made so that people can make an informed decision.

James Freyr wrote:Yes you can. A 12v charger can charge any 12v battery. The difference is your scooter battery is 7ah (amp hours, for those reading who may not know) and a car battery is hundreds of amp hours, so it isn't going to take very long to charge the scooter battery compared to a automobile battery. If the charger is an old analog style where you turn a knob to set the number of hours to charge, put it at the lowest setting. If it's a new digital charger, it should know when the battery is charged and will stop charging. Over charging makes the electrolyte liquid in the batteries boil and it just kills the life of them, then they lose their ability to hold a charge. If it's charging and you hear fizzing like soda pop, the electrolyte is boiling, so stop charging.

One more note, is the age of the battery in question. If this scooter battery is 5 or more years old, and it's a lead acid battery, it may just be time for a new one. There are interesting techniques I've seen on youtube of revitalizing old lead acid batteries by dumping the electrolyte, then filling with a epsom salt solution, and getting many more years of life out of them. I have yet to try this myself, but the information is out there.

I disagree strongly with several of your statements here.  You cannot charge any 12V battery with any 12V charger.  A car battery is not hundreds of amp hours.  Not all digital chargers will protect against overcharging (I know, I have made that mistake before of assuming that).  You cannot "recharge" a lead acid battery with epsom salt solution... saltwater batteries do work but they are much, much less energy than the electrolyte solution that originally came with the battery.  To the point where the battery will no longer be a 12V battery and will have orders of magnitude less capacity.  Why would you not just order more electrolyte and refill it for $20 or less?

I have the non-Mini version of that charger and it is indeed fantastic.  However, neither one has ever been $16 to my knowledge.

Here is the one I have:
https://amzn.to/3vFbeN3