LiFePO4 Deep Cycle Batts (again)

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DonTom

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I decided I have room for this 300 AH battery in my RV. A bit pricy, but it will probably outlive me and should be good even for my next RV.

But I have a few question before I hit the "buy now".

While charging while driving and running by the alternator on such a battery if this battery starts as mostly discharged, after several hours of driving, what SOC can I expect? Say after a six hour drive. I assume it will never get to 100% by driving, no matter how far I drive. I assume the VR in the GM RV will act like any other battery and have perhaps above 14 volts to start with and then decrease to below 14 volts in a few minutes--is this correct?

The new location will not be in my battery box, it will be under the side bed next to my water heater. Are there any issues there? That is the only place I can find the room.

I discovered an easy way to get a battery cable over there, right across the floor! Only the cabling will end up the battery box. But that cable won't be in my way (But this the type of stuff I would only do in an older RV). It will be a plug-in cable with 175 amp sexless Anderson connectors. So it will also be easy to move out of the way when not being used. And another cable of the exact same type going to my ham radio stuff (which is really overkill for 100 watt CW).

Are there other things I should consider before I hit the "buy" button?

Or perhaps even a different battery, for whatever reason?

I would like as much info. as possible before I buy. Am In over looking any possible issues of any type with such a battery? I want to know what I can expect.

-Don- Auburn, CA
 
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John From Detroit

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I would not mind one of those at say 500 bucks but at 1500.. OUCH.

Going down the road the battery will charge according to a mix of factors that all need to be calculated
The size and V-out of your alternator.. they range from aroudn 75 amps to over 200. But you should not try to draw max amps for a long time.

The length and size of the wire and devices between Alternator and Battery. Bigger wire = faster charging. More "Connections" = slower charging.

So no I can not tell you how full it will be after six hours of driving

Also other loads on battery they slow charging.
 

DonTom

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I would not mind one of those at say 500 bucks but at 1500.. OUCH.

Going down the road the battery will charge according to a mix of factors that all need to be calculated
The size and V-out of your alternator.. they range from aroudn 75 amps to over 200. But you should not try to draw max amps for a long time.

The length and size of the wire and devices between Alternator and Battery. Bigger wire = faster charging. More "Connections" = slower charging.

So no I can not tell you how full it will be after six hours of driving

Also other loads on battery they slow charging.
Thanks for the reply, but that is the type of stuff I already know.

Lith RV batteries require almost a volt more than lead-acid to get fully charged. So I assume it will NEVER get fully charged by only driving, but I was wondering how close it would get at 13.8 volts. Or however a GM alternator / VR would react to it. The charge current I would expect to be low because the charge voltage will be low for that type of battery, but there, I am not sure, as perhaps it draws more at lower voltages than lead-acid. They say they charge twice as fast. I assume that means it draws twice as much current. All this stuff isn't clear to me and those are the type of things I wanted to know here.

Likewise the converter has to be a higher voltage to get a full charge on such a Lith battery. But it isn't really necessary to charge to full anyway. But I still want to know this stuff.

IIRC, Lou has both a Smart Shunt and 200AH worth of Lith batteries. The Smart Shunt shows the SOC for the type of battery, IIRC. That is the type of number I was looking for here.

And any other info. about the differences between the Lith battery and lead-acid.

At the price of these things, I want to know as much as possible before I hit that "buy" button. I do have time on my side, as I won't be on another RV trip for a few months or so.

-Don- Auburn, CA
 

DonTom

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I just read most of the Q & A on that website. I don't know why I didn't do that first, as most of my answers were there.

The battery should be charged at 40 to 100 amps.

Charging voltage should be from 14.2 to 14.6 VDC.

At 13.8 volts from the alternator, I should be able to get up to around 90% SOC if I drive long enough. So that must mean the charge rate is below 40 amps while driving.

It all sounds reasonable to me.

I already moved my old lead acid battery out from the battery box and put it under that small bed. I will not leave it there, this is just for testing.

My old battery box now only has wiring and relays, only the wiring where the battery used to be located.

Anyway, everything works well from that location with my new wiring. Generator started right up and that is probably the largest load I will ever have in my RV from the house battery.

The new lith battery should be stored at 60% SOC. The same as my Zero motorcycles. Should not be left fully charged for months when not being used.

I just now ordered it, so I can complete the job (I figured there is no legit reason to wait):

Ship to:
Donald
AUBURN, CA


Order Total:
$1,715.99


-Don- Auburn, CA
 
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Lou Schneider

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IIRC, Lou has both a Smart Shunt and 200AH worth of Lith batteries. The Smart Shunt shows the SOC for the type of battery, IIRC. That is the type of number I was looking for here.

And any other info. about the differences between the Lith battery and lead-acid.
Unfortunately Don, due to leaving some key pieces at home I don't have that kind of information. But here's what I've found empirically boondocking with a pair of Lion Safari UT1300 batteries with limited metering for about 3 weeks now. The installation so far is a direct drop-in replacement using the stock Safari Trek systems.

The Lion Safari batteries have a built-in 5 LED SOC meter, with each segment indicating 20% capacity. This has been a lifesaver as relying on voltage to determine SOC is basically useless. There's not that much difference in voltage or performance to gauge what's left in the battery and the stock monitor panel bargraph voltmeter has all of it's LEDs on all of the time. I also have a DC clamp-on ammeter I use for spot checks on the charging rate.

Given that limited metering, I find I can go 4 days without discharging the batteries more than 60-80% as indicated on the bargraphs. When the batteries get down to a single bar (20%), idling the vehicle engine for 30-45 minutes restores another two bars of capacity, enough for another day boondocking (one of the boxes I failed to pack was the new carburetor and fuel pump for the Onan generstor, so it's out of commission until I get home).

After 4-5 days out I just pull into a full service RV park and let the Magnum Freedom 10 MSW inverter/charger fill the batteries overnight and I'm good to go again. Along with a full water tank, empty holding tanks and clean laundry.

My electrical usage has been pretty average - one or two fluorescent lights 3-5 hours a night, enough TV and DVD player use to watch a movie in the evening, recharging my phone and tablet from their USB charging cords via a 12 volt cigarette lighter adapter (usually the full battery capacity on the tablet, 50% on the phone) and running my Mobley hotspot continuously. Plus normal stuff like the water pump, a Fantastic Fan for ventilation during the day and the furnace as often as needed to stay comfortable during high 30 to mid 40s nights.

So how do they charge? The Magnum inverter puts 50 amps (it's full rating) bulk charging the batteries at 13.6-14.1 volts as measured at the battery terminals from <20% to the full 5 bars of charge, filling the two batteries in 4-5 hours.

Using the engine, the alternator also puts out 14.1 volts (again, measured at the batteries) for the first 10-15 minutes at a fast idle (1000 rpm with a piece of wood holding the accelerator open) pumping 50-70 amps in. Then the voltage decreases to 13.6 volts giving a 30-40 amp charge rate. The batteries acceptance is pretty constant over the full range of SOC.

A 3-4 hour driving day fills the batteries completely (5 bars).

Likewise, their output is constant over the operating range. I don't hear any difference in fan speeds regardless of the SOC. This means the furnace operates reliably as low as I've drained the batteries, unlike lead acid batteries that have enough voltage sag to make it's operation iffy as the fan speed slows as they discharge. One of Lithium differences is unlike lead acid, it's current capacity doesn't decrease as the SOC goes down, i.e. they don't fade out. Yes, the voltage drops a bit but not enough to make a noticeable difference in performance. Out of curiosity I fired up a 1500 watt hairdryer with the batteries showing one bar and an incandescent light I was watching didn't dim or even even flicker.

In short, I'm completely sold based on the batteries performance during this shakedown cruise and I'm sure I'll like them even more as I get the solar and more metering installed.
 

DonTom

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The Lion Safari batteries have a built-in 5 LED SOC meter, with each segment indicating 20% capacity. I also have a DC clamp-on ammeter I use for spot checks on the charging rate.

I don't think the battery I just purchased has those lights, but it will be mounted in an area where I will not be able to see it anyway. But I do have the SmartShunt wired in. That sure is a handy gadget for when working on the DC stuff.

After I use the new battery for a while, I will report back here. 300AH is probably overkill for me, but I generally like a little overkill with this type of stuff. I sometimes boondock for more than two weeks at a time and it's often when the days are very short, like my trip a couple of months ago. And I probably drain faster than most with my ham radio stuff. I know I will like that very steady 12.8 volts. I will probably never see it drop from 12.8 with my 300 AH battery. Need to get to the last ten percent of the charge for that, and I probably never will.

I am getting a new lith converter, mainly so I will have a few more charging amps. It will be 55 amps, up from the 40 I had which is just the min for that battery. They recommend 50 amps, but up to 100 amps is okay. My new converter will be 55 amps and designed for lithium, but a strap can be removed for charging lead acid at a lower voltage. I am giving my old converter to a buddy in Reno. His old junky converter crapped out and isn't worth repairing and he has lead-acid house batteries.

Thanks for the reply, you had some good info. there as is!

When my new battery gets here, I know am going to feel like boondocking somewhere for a couple of weeks!

-Don- Auburn, CA
 

AStravelers

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Nothing wrong with paying about $565 for each 100AH of lithium battery. That is a good price.

With the smart shunt to monitor your battery SOC and to know the amps your alternator is pushing into the battery, you will be able to be sure you are not overtaxing your alternator.

You will also really like that you never need to get the battery fully charged, like you do with lead acid.

Sounds like a good setup to me.
 

DonTom

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Nothing wrong with paying about $565 for each 100AH of lithium battery. That is a good price.
Did you see this? It is just a little more costly than many other 300 AH, but is the size of a 200AH. But it is still as heavy as perhaps other 300 AH Lith batts.

"Is this actually 300ah? How is that correct with the physical size the same size as all the 200ah batteries??

Answer:
It is actual 300Ah lithium battery with upgraded battery cells. The 300Ah battery has higher energy density, so it can achieve 300Ah capacity with same size as but heavier than our 200Ah battery. Also our 300Ah battery has 200A built-in BMS, supporting 2000W load power.
By Ampere Time US SELLER on October 13, 2020


When I run my microwave oven from my inverter, It will be interesting to see no battery voltage drop at the battery.

-Don- Auburn, CA
 

AStravelers

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Will Prowse has a video review of a 50AH "Ampere Time" batttery. While the build quality is good the low temperature sensor doesn't work because it is a high temp sensor. This would allow the battery to be charged while the batteries internal temp is below freezing. This may not be a problem for the OP since the battery will be inside the trailer, under the bed.
 

DonTom

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Will Prowse has a video review of a 50AH "Ampere Time" batttery. While the build quality is good the low temperature sensor doesn't work because it is a high temp sensor. This would allow the battery to be charged while the batteries internal temp is below freezing. This may not be a problem for the OP since the battery will be inside the trailer, under the bed.
Yeah, needing to charge while freezing should never be a problem for my motorhome. I see you have 400AH worth of lith. With quite a bit of solar. Can you drain that battery / batteries (how many?) down much even when you try your best to? :)

You probably often boondock for weeks at a time with that system.

-Don- Auburn, CA
 

AStravelers

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We use about 100 to 150 AH a day, so with 400AH of lithium batteries and 625 watts of solar the batteries get well charged from solar most of the time.

In 2016, the first year we had the lithium batteries we went on our Alaska trip. 4 1/2 months from Portland, OR through Canada and Alaska and back to Portland. On this trip we only had elect hookups for 2 nights when we stayed in a city operated RV Park in Skagway, AK. The remainder of time we just used solar and batteries. We only ran the generator, to charge the batteries, for about 1.5 hours one day because of multiple days of heavy clouds. We powered my wife's CPAP, charged her power wheel chair and scooter, used the microwave, watched satellite RV with our Wineguard Trav'ler dish while in AK and in general lived life as though we had elect hookups.
I figure the lithium paid for itself in the savings we had from not staying in RV parks at $40-$50 a night on that trip.

The details of our Alaska trip are in our blog, look for the link in our signature line if anyone is interested.
 
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DonTom

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I am receiving my new battery today, according to UPS tracking. It was supposed to get here between March 6 and March 10, so it's two days early.

I am excited to try it out.

I want to see how it works with my 4KW inverter when I use my microwave oven and stuff like that and see how it compares to my old lead acid battery.

I will be watching my SmartShunt as I do such.

I already installed my switchable lith converter, which came yesterday.

-Don- Auburn, CA
 

DonTom

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The new battery is now installed. 13.2 volts right out of the box? I was expecting 12.8. I like the 13.2 better anyway for my ham gear when boondocked. But I wonder what load it takes to drop to 12.8.

This 300 AH battery is not light. It weights almost as much as my 114 AH Lead Acid Marine battery that I just removed.

I put a marine battery in there when one of my 6V Trojans crapped out in Death Valley (shorted cell in a six volt batt) so I went to Pahrump's Wally*Mart to get the 12 V marine battery to complete the trip. I knew I would replace it when I got home, but I wasn't then expecting to spend $1,716.00 (includes tax) to replace it. But I think it's money well spent.

I am going to read some of the manuals first that came with the battery and then I will do some testing on it in the RV.

I just came back here to take a short break. I had to walk up hill a ways with the battery to get it installed. Long driveway here to where the RV is parked.

-Don- Auburn, CA
 

DonTom

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I put a couple of cups of water in my MW oven and checked the battery voltage as I used my inverter. Battery voltage, unloaded, 13.20 VDC. I run the MW over for a full minute, voltage (measured right on the battery) slowly drops to 11.5 VDC after one minute of my 4KW inverter running it boondocked. But as soon as the load goes away, that 13.20 volts comes back instantly.

The voltage drop was more than I expected for a 2,560 watt capable battery.

So then I start my generator, it started so fast that I could not even get a measurement anywhere during the starting. The starter ran faster than ever with that 13 volts and the generator started up in less than a second.

I did this testing fresh out of the box with no charging at all.

-Don- Auburn, CA
 

AStravelers

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I put a couple of cups of water in my MW oven and checked the battery voltage as I used my inverter. Battery voltage, unloaded, 13.20 VDC. I run the MW over for a full minute, voltage (measured right on the battery) slowly drops to 11.5 VDC after one minute of my 4KW inverter running it boondocked. But as soon as the load goes away, that 13.20 volts comes back instantly.

The voltage drop was more than I expected for a 2,560 watt capable battery.

So then I start my generator, it started so fast that I could not even get a measurement anywhere during the starting. The starter ran faster than ever with that 13 volts and the generator started up in less than a second.

I did this testing fresh out of the box with no charging at all.

-Don- Auburn, CA
Try your test again with your batteries fully charged, or at least to the 70% to 80% SOC and I think you will be much happier.

I believe your battery SOC is probably down to 30%-40%, maybe even lower. Trying to guesstimate the SOC from voltage reading for lithium is difficult.

I believe that the lower your SOC the greater the voltage sag under load.

I just went out to our RV parked in our back yard and tested the voltage drop for our 5 year old lithium batteries and the voltage drop was only 0.3V for our fully charged batteries.

My battery monitors were showing 100%. To remove high battery voltage of 13.7V I ran the gas elect fridge on elect (a total load of 45amps) for a couple of minutes which brought the voltage down to 13.4V. I then ran the microwave for 1 minute to heat water (a total load of about 150amp). Now the resting voltage was down to 13.3V. I ran the microwave again for about 30 seconds. At the 150amp load the voltage dropped to 13.0V a drop of only 0.3V

I have four 100AH lithium batteries.
 

DonTom

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Try your test again with your batteries fully charged, or at least to the 70% to 80% SOC and I think you will be much happier.
Yeah, I was thinking the same thing. I wondered what SOC they ship them out at. No way to tell how charged they are until I know I have them fully charged. Can't tell by the voltage until it drops at the last 10%.

Yeah, I was planning on doing the same test again after they are fully charged by running the converter all day today.

-Don- Auburn, CA
 
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UTTransplant

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Our new batteries were supposed to arrive yesterday, but they are stuck in Indiana somewhere for a “delivery exception.” Luckily we aren’t leaving until at least May so we still have time.
 

DonTom

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Our new batteries were supposed to arrive yesterday, but they are stuck in Indiana somewhere for a “delivery exception.” Luckily we aren’t leaving until at least May so we still have time.
What type of battery are you getting?

I am about ready to test my 300 AH lith batt again. I removed the charging about an hour ago, so I am going to check the voltage difference under a heavy load. I assume it is fully charged as the lith converter turned off. Fully off, no charge current at all. I didn't know they did that. Different from the lead acid converters I have used. I guess I have to get down a SOC or two for the converter to come back on.

KInda makes sense when the voltage is so high even when not being charged at all.

-Don- Auburn, CA
 

DonTom

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I just completed the testing.

Rest voltage (no charge for an hour)=13.54 VDC
118 amp draw (around 1486 watts)for 60 seconds = 12.60 VDC (measured right on battery terminals). Battery recovered to 13.2 volts within 30 seconds after load was removed.

In above, there was a continuous slow drop in voltage during the 60 seconds under load. My SmartShunt (just calibrated for 300 AH after being fully charged) then said I had 99% SOC left.

Then, just after that, I did a 2nd test, which I find much more interesting:

Resting voltage (no load)= 13.20 VDC
Inverter and MW oven on now for three more minutes:

In one more minute, the voltage was at 12.50VDC at a draw of 115.2 amps (1,440 watts) and then perfectly steady. It would not drop below 12.5 VDC in a total of 4 minutes testing with a load of 115.2 amps and so the battery then was happy at this load with no more dropping of voltage.

Battery recovered to 13.10 volts in around five seconds when the load was removed.

While different than I expected, a steady 12.5 volts without further dropping under such a heavy load is impressive, IMO.

After all this I was at 97% SOC.

My new ( a couple of months old) 100AH lead acid, fully charged, would be well below 12.5 volts as soon as the same load was applied and drop voltage very fast (but I don't now remember the numbers).

-Don- Auburn, CA
 

UTTransplant

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What type of battery are you getting?
We have 600 amp hours of LifeBlue lithium coming (3 batteries). New charge controller for solar has arrived plus some other miscellaneous stuff. Kevin is getting anxious! He loves messing with the motorhome.
 
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