# Wen generator / inverter battery question.



## Robert Whitehead (11 mo ago)

I have a new Wen Model 56380i gen / inverter that stays outside year round. I read in the manual that it can damage the lithium Ion starting battery if the generator is started below 25 degrees F. The generator charges the battery while it runs and damage will occur below 25 F. I live in Maine and during the winter it is always below 25F. Should I consider swapping out to a lead acid battery or is this not a big issue? Thank you for any advice.


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## GenKnot (Dec 20, 2021)

With a lithium-ion battery it is best to bring it inside the house to keep it above 25F. The main problem is that they don't like to be charged below 25F. I would put a good battery tender on it inside the house so that it is ready to go when you need it. You should be able to take a nice warm battery outside and start the gen. Once the gen is running it should keep the battery above 25F especially if the gen is in some type of enclosure.


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## GenKnot (Dec 20, 2021)

I should add that there are different opinions about storing lithium-ion batteries. Some say to not store them with a battery tender connected, and some say it is okay. I think it is important to get a tender that is made for lithium-ion and definitely not use a lead-acid tender. The low self-discharge rate of a lithium-ion battery can allow them to be stored without a tender for a few months.


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## zz28zz (Nov 24, 2021)

I was going to suggest a pad type battery heater and found one on Amazon but it said not for lithium type batteries.
Can lithium batteries use a heat pad? 

I have seen what happens when things go wrong with LI batteries. It's not pretty.


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## OrlyP (Oct 19, 2021)

TL;DR For cycle use, it's ok to charge it to 100%. But for standby use, I wouldn't go above 80% state of charge (SoC).

Li-Ion cells don't like to be always topped-up or fully-charged either. 50-60% is the ideal SoC for storage to get max longevity out of it. Keeping them at either full-charge or empty for a length of time makes the chemicals unstable and actually start to corrode internally, reducing its life. However, keeping it at 75-80% is a good compromise between longevity and available capacity.

You can, say, charge it to 80% and check on it monthly. But since they have low self-discharge, you really don't have to recharge them frequently. If it's just sitting there in storage (at room temperature), charge it back to 80% once it gets down to around 60-70% and it'll be fine for months.

The SoC% depends on the specific battery. Some Li-Ion has a nominal voltage of 3.7 and a full-charge voltage of 4.2V. Others may be 3.6V/4.1V. You'd want to keep the battery just slightly above its nominal voltage.


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## zz28zz (Nov 24, 2021)

I have a drone and a couple of R/C trucks that use Li-ion batteries and concur abt storing at 50% charge. My batts are 4 or 5 years old and still working well. The battery charger has a mode that will charge or discharge them to get them to the optimum storage state while monitoring each cell. A good charger makes all the difference with these type batts.


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## OrlyP (Oct 19, 2021)

@zz28zz .. Same here... I have DJI Phantom 3 Standard from 2016. Still flying.

I've set the Intelligent Flight Battery (DJI's fancy name for BMS) to start shedding charge after 3 days of unuse. That drops down the SoC to 60% in a span of about 5 days, if memory serves.


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## OrlyP (Oct 19, 2021)

And oh, I need to clarify something.

Although the Li-Ion/LiPo cells themselves may have very low discharge, the battery management system (BMS) that is usually required to maintain and protect them does consume a tiny bit of quiescent current. That's why it's important to check the battery voltage frequently and not assume it will still have the same charge after a year.

As mentioned, check it every month or so, or as frequent as you exercise and maintain your generator.


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## zz28zz (Nov 24, 2021)

Getting back to the OP question abt swapping in a lead-acid, suppose you would need to know if the gen has a special charging circuit for LI batts. It might over-charge a lead-acid batt if it does. After seeing the bad reviews for batts on the Wen site, this might be worth looking into if you can find a lead-acid batt that fits.


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## GenKnot (Dec 20, 2021)

zz28zz said:


> need to know if the gen has a special charging circuit for LI batts


The schematic in the manual does not even show that the battery has a method of being charged, so that's a dead end.
The battery replacement on the Wen website does not have any useable information about the battery.
The manual describes the battery as being 1.6Ah. That must be a misprint. 16Ah maybe?

Notice that the manual says that you can put an "automatic trickle charger" on it (see post #2). That can be very misleading to many because the charger for a Li-Ion battery needs to be "smart" and intended for Li-Ion use as mentioned in the above posts.

I would recommend that the OP contact Wen and get very specific information about the use and care/storage of this battery. Also, as to how it is being charged when used in the gen (intelligent vs dumb circuitry).


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## drmerdp (Apr 10, 2018)

Sounds unusual to have a lithium ion battery, especially 1.6ah. There is so little info about the battery. No dimensions or group number. Even the replacement battery’s price of $48 seems off. Is it equipped with a lithium battery from the factory while replacements are lead acid or AGM?


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## OrlyP (Oct 19, 2021)

GenKnot said:


> The manual describes the battery as being 1.6Ah. That must be a misprint. 16Ah maybe?


You'd be surprised to know that they do exist. Mainly used for small motorcycles or scooters. I would imagine that inside are just three 18650 1.6Ah cells in series (3S), mounted inside maybe a 5A-BS motorcycle type battery package. It technically has the same battery specs as my small 12V cordless drill.

I guess these small engines doesn't need much to crank. My only worry is that it may not have enough reserve to repeatedly crank an uncooperative engine.



> Notice that the manual says that you can put an "automatic trickle charger" on it (see post #2). That can be very misleading to many because the charger for a Li-Ion battery needs to be "smart" and intended for Li-Ion use as mentioned in the above posts.


Unless the BMS is the "smart" component. Many drop-in Li-Ion and LiFePO batteries don't need a new charger. The internal BMS appears smart enough to balance the cells and control current and voltages.


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## GenKnot (Dec 20, 2021)

But three 1.6ah batteries in series is 4.8ah. That might crank a gen.


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## OrlyP (Oct 19, 2021)

GenKnot said:


> But three 1.6ah batteries in series is 4.8ah. That might crank a gen.


When in series, you're adding the voltage of individual cells. The Ah or capacity stays the same. 3S is 3 cells in series. Typical setup to reach 12V nominal (if each cell has a full-charge voltage of 4.2 V).

In parallel, you're adding the capacity of the individual cells. The voltage stays the same.


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## GenKnot (Dec 20, 2021)

Thanks Orly. Yeah, I didn't explain it correctly. The total power contained in the 3 X 1.6Ah series arrangement is increased because the voltage is increased, but the Ah of the 3X cell as a whole remains the same 1.6Ah. I still don't think the description of it being 1.6Ah is correct. Lithium-Ion batteries can put out one heck of a lot of current, but I don't think there would be any reserve if the gen didn't start immediately.


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## drmerdp (Apr 10, 2018)

1.6ah is too small to provide more then a few seconds of cranking before running out of juice or depleting the battery to a low threshold. It’s one thing if it was a 50-100cc scooter but it’s a 212cc engine.


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## OrlyP (Oct 19, 2021)

I agree it's puny compared to what we're used to but it should be able to crank it at least a few times, much like a 12V cordless drill could start it.

IIf I can be devil's advocate for a minute, I guess they did that to save money and just simply didn't give much importance to it... given that it's just a small engine with a recoil for backup. Though, that should shave off a couple lbs from gross weight, at least.


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## 3Dave (12 mo ago)

A 12V 1.6ah motorcycle battery is capable of, on average, 100 cranking amps. In an ideal world it can produce 100A for 57 seconds, 75A for 77 seconds. In reality it most likely would crank the engine for ~30 seconds if it's drawing 100A, maybe 45 seconds at 75A. Peukert's Law does not apply here.

We would need to know how much current the starter is actually pulling to go any further with this.


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## OrlyP (Oct 19, 2021)

3Dave said:


> A 12V 1.6ah motorcycle battery is capable of, on average, 100 cranking amps. In an ideal world it can produce 100A for 57 seconds, 75A for 77 seconds. In reality it most likely would crank the engine for ~30 seconds if it's drawing 100A, maybe 45 seconds at 75A. Peukert's Law does not apply here.
> 
> We would need to know how much current the starter is actually pulling to go any further with this.


For a baseline, my GX390 clone draws around 30A while cranking. The Wen has a smaller engine so probably 20A?


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## 3Dave (12 mo ago)

That's 288 seconds (4.8 mins) at 20A.
Check my math please: 1.6ah/20A= 0.08 hours. 0.08 X 3600 sec in an hour = 288 seconds

Again, that's ideal. Reality its something different


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## OrlyP (Oct 19, 2021)

Yeah, that's ideal.

Assuming that the cells can discharge at 10C, that means, it can do 16A continuous. The catch is, there's this evil thing in all batteries; internal resistance. As the battery gets more discharged, internal resistance increases. So in reality, the battery might be giving out 16A in the first few seconds, but with just 1.6Ah of capacity, the current just goes downhill very quickly after that. It gets to a point that the remaining capacity becomes unusable due to the high amperage requirement.


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## 3Dave (12 mo ago)

Yep, that's part of the reality, but they are capable of delivering 90+A.
We can include IR of the cables and connectors, the starter will demand more current as the applied voltage drops because of all of the above, etc. A typical lawnmower starter can produce usable torque and rpm down to ~8V given adequate current. You just need to spin it fast enough to overcome the compression release mechanism. A generator wouldn't be any different.

My point is a LifePo4 1.6ah battery is not a bad match for a small engine application. I would be more concerned with the charging system. LifePo4 are picky when it comes to overcharging.


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## GenKnot (Dec 20, 2021)

3Dave said:


> LifePo4 are picky when it comes to overcharging.


Perhaps the battery in question has internal BMS. There is just not any info on the Wen website. 

There is an interesting comment on the Wen battery page as follows:


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## 3Dave (12 mo ago)

Yea, they don't get very good reviews on their batteries. Maybe that's what prompted the change to LifePo. But then again, my original Champion SLA battery didn't last a year. I replaced it with an AGM and so far so good. I may try one of these small LifePo's when mine dies.

To the Original Poster: You're not a very good candidate for being a LifePo user. I would find an SLA equivalent just for the piece of mind. If you don't mind maintaining 2 batteries, use the SLA in the winter and LifePo above freezing.


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## OrlyP (Oct 19, 2021)

So far, all references to this battery says it's a lithium-Ion. 

LiFePO4 would be a totally different animal. But benefit of the doubt, they could just have written it as Li-Ion when they actually have LiFePO4. 

But I saw online a couple of 12V Li-Ion batteries.

It's very clear in the marketing materials that they're pushing this for use with generators. 45C discharge rate on this one.








22.88US $ |12V 0.8/1.6Ah Lifepo4 Motorcycle Jump Starter Lithium Ion Battery High Quality Gasoline Engine Battery with Voltage Protection|Electric Bicycle Battery| - AliExpress


Smarter Shopping, Better Living! Aliexpress.com




www.aliexpress.com





Also, "CCA - 95A"... 





SHIDO LTX4L-BS 12V 1.6Ah 95A Li-ion battery -+ | PATAREID.EE







www.patareid.ee


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## GenKnot (Dec 20, 2021)

OrlyP said:


> LiFePO4 would be a totally different animal. But benefit of the doubt, they could just have written it as Li-Ion when they actually have LiFePO4.


Good find, Orly!
I am inclined to think the 1.6Ah LiFePO4 battery in the first link is probably it. It matches up with the little bit of information Wen provides (except for calling it lithium-Ion), and it is marketed for generator use. If I were Wen, I would be including this info in the sales literature and the manual. A LiFePO4 with an onboard BMS is a good thing. Still likely gives the OP an issue with charging below 25F though, but at least you can't hardly damage the battery like you might with a standard Li-Ion.


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## drmerdp (Apr 10, 2018)

3Dave said:


> Yea, they don't get very good reviews on their batteries. Maybe that's what prompted the change to LifePo. But then again, my original Champion SLA battery didn't last a year. I replaced it with an AGM and so far so good. I may try one of these small LifePo's when mine dies.
> 
> To the Original Poster: You're not a very good candidate for being a LifePo user. I would find an SLA equivalent just for the piece of mind. If you don't mind maintaining 2 batteries, use the SLA in the winter and LifePo above freezing.


Less then a year on a battery maintainer? I got 8years out of my champion SLA, its still going strong 2 years later for my brother-in-law.


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## iowagold (Jan 22, 2020)

standard SLA
we get 4 years on lawn and garden batteries on the good maintainers...
10 years on auto and truck batteries.
no kidding!

lawn and garden batteries are a one year thing unless you use the good chargers.


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## 3Dave (12 mo ago)

OrlyP said:


> So far, all references to this battery says it's a lithium-Ion.
> 
> LiFePO4 would be a totally different animal. But benefit of the doubt, they could just have written it as Li-Ion when they actually have LiFePO4.
> 
> ...


I surmised it to be LifePo4 because Wen said it could be charged below 0°C. Their lawyers would have a fit if it was a Lithium Ion. Plus a LifePo4 can be charged with a less elaborate charger without concern of burning down the house. 

Many Lifepo4 packs in this form factor just say Lithium Ion. HERE is an example. Read its description


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## 3Dave (12 mo ago)

drmerdp said:


> Less then a year on a battery maintainer? I got 8years out of my champion SLA, its still going strong 2 years later for my brother-in-law.


The original battery came to me DOA. I assume it was sitting in the box under charged for months before I received it. I nursed it back to life the best I could.

This generator gets ran for hours a week in the field. It's never needed a tender. The AGM is still going strong after 2 years.


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## drmerdp (Apr 10, 2018)

3Dave said:


> The original battery came to me DOA. I assume it was sitting in the box under charged for months before I received it. I nursed it back to life the best I could.
> 
> This generator gets ran for hours a week in the field. It's never needed a tender. The AGM is still going strong after 2 years.


Gotcha, sometimes you just get a bad one.


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## macdenewf (Sep 3, 2021)

Robert Whitehead said:


> I have a new Wen Model 56380i gen / inverter that stays outside year round. I read in the manual that it can damage the lithium Ion starting battery if the generator is started below 25 degrees F. The generator charges the battery while it runs and damage will occur below 25 F. I live in Maine and during the winter it is always below 25F. Should I consider swapping out to a lead acid battery or is this not a big issue? Thank you for any advice.


Not quite the same scenario but similar topic. I keep my dreamt 24v lithium ion


Robert Whitehead said:


> I have a new Wen Model 56380i gen / inverter that stays outside year round. I read in the manual that it can damage the lithium Ion starting battery if the generator is started below 25 degrees F. The generator charges the battery while it runs and damage will occur below 25 F. I live in Maine and during the winter it is always below 25F. Should I consider swapping out to a lead acid battery or is this not a big issue? Thank you for any advice.


Not the same scenario but comment on lithium ion. 
I keep my Dewalt 20v lithium ion Batteries in my garage in Houston. Rarely gets cold but I can confirm that if the batteries are NOT on the charger they quickly deplete the charge. I’ve always thought it was the heat. They do however stay fully charged on the dewalt battery charger.
I don’t know how well lithium ion do in cold use but if you can’t leave the charger attached I’d say you’re also looking at depletion issues in the summer as well
I’m pretty certain I use a 12v sealed lead acid AGM battery on my gen set and I don’t recall ever seeing the same depletion issue. I do keep it on a charger though. 
Maybe worth considering replacing the lithium ion for a couple of reasons. The info available on line does suggest that charging and using lithium ion in freezing temperatures is not recommended and based on what I’ve seen in hot temps…will also let you down unless left on the charger. 
cheers.


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