Lipo4 battery running an inverter, need help finding a proper maintainer

[OCMerrill]

Where I live we experience power outages several times a year. My garage door opener is blocked by my trailer requiring me to pull a "George of the Jungle" in order to pull the cord and open the door. My Marantec Opener is mounted to the far right side of my garage. It was pretty trick 20 years ago when installed and have never had a problem. Done so I could get my Jeep in the garage, now long gone.

About 6 months ago I installed a 600 watt inverter, a 100 ah Lipo4 battery, and the system works perfectly or so I thought it would.

The issue is the several chargers I've tried to maintain the battery. With the Li setting, and I am on my 6th brand try, these Lipo4 chargers love to charge the battery up.
Then they say fully charged on the screen while the voltage on the inverter screen starts to dwindle. One would think that a charger maintainer would actually maintain the battery.

This is not happening, the inverter drops eventually to 11v, and the alarm goes off usually at 2-3am. The chargers say full as the inverter is playing a horn that will wake the dead.

Any takes? Brands? Something AMERICAN made maybe thats not a LIE? 12.8 V in a Lipo4 is considered 20%. This battery has been brought down into the 11's several times now.

Inverter says 11.3v, charger says good. LI is set. The inverter uses about 2 watts and the opener uses 6 watts constant. The combined eventually drains the battery.

Says 13.3v now however a hr ago it said 11.1v and good. I unplugged it and plugged in back in and is started charging.

Its like I need a plug in timer to reset these things a couple times a week so they just charge since they don't maintain.

 

[monkeyswrench]

Could you run an inverter/charger combo from an RV? Hold on....let's call @The Chicken ...he plays with LiPo batteries, inverters and wires.

 

[OCMerrill]

Well I borrowed the Lipo Maintainer from my son's Harley made by Battery Tender and installed it shortly after I spewed all this.

Its charging currently. It does an excellent job of keeping His Harley's Lipo4 charged. His bike came new with a Lithium Battery and now has a Noco Lipo from the Battery Store past year. We'll see but I was trying to avoid the $100 4.5 amp charger mentally I guess.

 

[mesquito_creek]

There is no “maintenance” charge on lifepo4. You do not float charge them or anything other than apply the end state voltage that you desire IE 13.8 on a 12v battery.

I would remove the battery and fully charge it. Then remove the charger and validate that the battery is at 13.8 ish.

Then rest the battery for a couple days… it should not lose much or any charge.

I have been using the battery tender brand charger from Costco for 50 bucks successfully for a while now.

If you are cycling that battery daily with open/close on the garage opener, you could just have cycled out the battery.

 

[hallett21]

I think I’d buy a UPS and plug the opener in to it.

 

[mesquito_creek]

Also check how much the draw is on the inverter. Most of the cheap Chinese inverter draw a lot of standby power. So you will always see that voltage drop as the inverter is drawing power while it is doing nothing. That’s is using up the cycles on the battery. I have some of those inverter and the standby drawdown is criminal…

 

[mesquito_creek]

I set this up for you. This battery has been sitting off the charger for a month and holding 13.9

Here it is when I apply the charger… 14v

 

[mesquito_creek]

If that inverter is drawing 16watts in standby…. That will fully cycle every watt of your 1200 watt hour battery in 3 days having done nothing.

 

[mesquito_creek]

I set this up to compare the standby power consumption… I will draw it down to about 13v like your picture and then connect the battery tender to see if it can properly charge it back to +13.8v like you are attempting.

 

[OCMerrill]

Also check how much the draw is on the inverter. Most of the cheap Chinese inverter draw a lot of standby power. So you will always see that voltage drop as the inverter is drawing power while it is doing nothing. That’s is using up the cycles on the battery. I have some of those inverter and the standby drawdown is criminal…

40 Watts door going up, 66 watts door down. I already owned this inverter and at 600w its a bit oversized. Idle 2 Watts inverter, 4 watts opener.

What I need is a maintainer that will auto charge the battery from 12.8v (80% discharged) back to 14.2-.6 or 80% charged. Its needs to be recharged every 4th day from 20 to 80%. min.

Yes the door gets used daily. Son's Harley goes in and out, I am working on boat projects (boat is at the river) with the items I brought home.
We head back 17th of October. So I will watch this and just keep recharging. I just know the minute I back off the power will go out.

 

[mesquito_creek]

40 Watts door going up, 66 watts door down. I already owned this inverter and at 600w its a bit oversized. Idle 2 Watts inverter, 4 watts opener.

What I need is a maintainer that will auto charge the battery from 12.8v (80% discharged) back to 14.2-.6 or 80% charged. Its needs to be recharged every 4th day from 20 to 80%. min.

Yes the door gets used daily. Son's Harley goes in and out, I am working on boat projects (boat is at the river) with the items I brought home.
We head back 17th of October. So I will watch this and just keep recharging. I just know the minute I back off the power will go out.

What is the 16w showing on your picture of the inverter? Idle consumption?

 

[OCMerrill]

I think I’d buy a UPS and plug the opener in to it.

I put solar on my motorhome and have a spare converter. I thought also about using a charge controller with it. Seems pretty inefficient, its a 60amp unit, its 20 years old, and was replaced for the Lipo4's I put in the motorhome with a modern unit. This system works well along with the DC/DC charger. Those batteries are happy.

 

[OCMerrill]

What is the 16w showing on your picture of the inverter? Idle consumption?

The light for the opener was on as I reconnected the charger and opened the door. I have led light bulbs in the opener. That picture was from a couple weeks ago.
Also when you cross the LED sensors for the garage door the wattage pick up a for a bit.

 

[mesquito_creek]

I plugged my garage door into this experiment and I will let you know how the battery tender behaves for the next few days

 

[OCMerrill]

@mesquito_creek

New plan because the 4.5 maintainer same as you will not add charge however there was no voltage drop either some 16 hrs later. So it will maintain
but as the door gets used it will eventually sink.

I will place the 20 amp charger on a multi day timer. I'll start charging every other day for now.
I'll leave the timer set for 6 hrs every other day. We'll see how that goes.

Since I cant find one to perform like this, I rig this up instead.

Edit - Maintained through the night. 13.3v all green on the charger. Did not expect it. My Iphone struggles. I had just opened the door also.

 

[OCMerrill]

I plugged my garage door into this experiment and I will let you know how the battery tender behaves for the next few days

View attachment 1434380

Thanks for adding in here and going out of your way to help.

I am for sure interested to see what you come up with.

 

[mesquito_creek]

Thanks for adding in here and going out of your way to help.

I am for sure interested to see what you come up with.

I added a 1500 watt heat gun to speed up the test…

 

[mesquito_creek]

If you have a good lead acid battery you might swap it out and make sure something in the lifepo4 BMS or capacity isn’t confusing the charger…

 

[mesquito_creek]

One thing I am noticing is that with no load my inverter fan is running a lot after applying the heat gun to draw down the battery. It’s hot in chandler AZ and the thermostat on that inverter must not like it. That fan will zombie away quite a bit of that 4.5 amp charger.

 

[mesquito_creek]

@OCMerrill
I started at 13.9v and applied the heat gun twice to discharge the battery to about 13.0v. The battery tender was able to return the battery voltage to 13.8v without any interruption.

I would think your system should work, I would look closer at the battery health, but that’s all I got for you. Good luck.

 

[bilz]

I have two of those costco 4.5 battery tenders. I really like them. It will take a bit to bring my 6v golf cart batteries all the way up, but it will do it.