Lithium Batteries

[Busskipper]

Originally Posted by oscarvan

Funny you should mention that, I was just looking at that, again, yesterday. I would do it right now if it wasn't for the $$.

That said.... they are coming down in price.

Yes.... for a lot more Ah per volume at a quarter of the weight it's a no brainer.

ONLY thing you're going to have to watch is the fairly narrow, and critical, charge voltage range. Not sure if my Magnum can be programmed to do that. Would have to talk to the Magnum people, but they are pretty accommodating.

This would be my choice.


https://www.lithiumion-batteries.com...on-battery.php

Right now I have 4-6V 225Ah lead acids, so 450Ah total with a max 50% discharge that's 225Ah.... Replacement cost about $800

The Li would give me a little more Ah for a couple of grand more in less space and a LOT less weight. Save some more money and put another one next to it and I'd be looking at 5-600Ah for half the weight..... I can run an AC off that for 6 hours....

I'm looking hard.

$5,000 can buy a lot of Fuel to run that generator......

[creativepart]

Originally Posted by hohenwald48

Are lithium batteries really $3K each? I had no idea they were that expensive.

No. There are plenty of 100ah LiPo4 battery options between $900 and $1,200 each. And they are drop in replacements for your LA batteries.

Typically they weigh less than half of a 6v Golf Cart LA battery.

My 4-12v 100ah Commercial Deep Cycle AGMs weigh 288 lbs and provide a usable ~200ah of power. It would cost around $1200 to replace them. 3-100w LiPo4 12v batteries would provide about 210ah of power and weigh 75 lbs. However it would cost ~$2900 to purchase them.

I can't see doing this until my batteries become a problem and perhaps by then the LiPo4 prices will come down some more.

Keep in mind, currently charging your LiPo4 batteries via your motorhome's alternator is frowned upon. Some folks do it. Other's install a LiFePO4 Battery Isolation Manager to minimize any issues from doing it. Other's disconnect the alternator from charging the house batteries entirely-but those folks usually have plenty of solar power available to keep the Lithium's fully charged when not on shore power or generator.

[jcussen]

Several more points, Battle Born will discharge 100%, so 100 amp BB is equal to two 100 amp LA batteries discharged to 50%. If they do have to be recharged to 100% [although unlike LA batteries they never have to be]. Charging to 100% in normally 3 or 4 times faster than LA, because max charger or solar power can be applied until fully charged , no absorb charge necessary. I do charge mine with alternator, but can connect and disconnect it with a remote boost solenoid. I do use a bluetooth monitor to read battery levels though.

[oscarvan]

Originally Posted by hohenwald48

Are lithium batteries really $3K each? I had no idea they were that expensive. I guess swapping out the lead acid for lithium is not done for financial reasons.

The 300Ah one is.... the smaller ones are cheaper.

Fuzzy math says $10-14 an Ah with progressive but small savings as you get bigger batteries.

https://www.lithiumion-batteries.com...deep-cycle.php

[oscarvan]

Originally Posted by creativepart

.Keep in mind, currently charging your LiPo4 batteries via your motorhome's alternator is frowned upon.

Aaaah.... interesting. Hadn't thought about that yet.....

There's quite a few solutions off the top of my head..... Have to think about that some more.

[oscarvan]

Originally Posted by Busskipper

$5,000 can buy a lot of Fuel to run that generator......

Except the per hour cost of a generator is a lot more than fuel.

Say I'm VERY nice to my generator and make it last 10,000 hours.

So there's $1 an hour to replace it.
Fuel is .5 to .75 gph depending on load. Let's say .6 average... fuel has in my time fluctuated between $2.20 and $2.90 let's call it $2.55 (But no telling the future, I know) say $1.50/Hr.

Maintenance, $50 every 200 hours, another $200 every 500..... so there's $.65 assuming NOTHING breaks, and NO LABOR.

Grand total.... $3.15 an hour to run it... (probably closer to $4)

If I install 600Ah (most of it usable) and I can nibble 2000 hours off my generator run time I break even.

I've owned my Moho 2-1/2 years, I have 630 hours on the generator.

[jcussen]

Originally Posted by oscarvan

Except the per hour cost of a generator is a lot more than fuel.

Say I'm VERY nice to my generator and make it last 10,000 hours.

So there's $1 an hour to replace it.
Fuel is .5 to .75 gph depending on load. Let's say .6 average... fuel has in my time fluctuated between $2.20 and $2.90 let's call it $2.55 (But no telling the future, I know) say $1.50/Hr.

Maintenance, $50 every 200 hours, another $200 every 500..... so there's $.65 assuming NOTHING breaks, and NO LABOR.

Grand total.... $3.15 an hour to run it... (probably closer to $4)

If I install 600Ah (most of it usable) and I can nibble 2000 hours off my generator run time I break even.

I've owned my Moho 2-1/2 years, I have 630 hours on the generator.

But won't you miss that constant annoying drone of your generator?

[oscarvan]

Originally Posted by jcussen

But won't you miss that constant annoying drone of your generator?

I don't mind running it, but if I can do what I have to do without it that is, of course preferred. Especially at night in a store parking lot.

[MRUSA14]

Originally Posted by oscarvan

Except the per hour cost of a generator is a lot more than fuel.

Say I'm VERY nice to my generator and make it last 10,000 hours.

So there's $1 an hour to replace it.
Fuel is .5 to .75 gph depending on load. Let's say .6 average... fuel has in my time fluctuated between $2.20 and $2.90 let's call it $2.55 (But no telling the future, I know) say $1.50/Hr.

Maintenance, $50 every 200 hours, another $200 every 500..... so there's $.65 assuming NOTHING breaks, and NO LABOR.

Grand total.... $3.15 an hour to run it... (probably closer to $4)

If I install 600Ah (most of it usable) and I can nibble 2000 hours off my generator run time I break even.

I've owned my Moho 2-1/2 years, I have 630 hours on the generator.

At that rate you will take almost 40 years to reach 10,000 generator hours. I wouldn’t worry about the cost of replacing the generator. The whole RV will need replacing before that, assuming you live that long.

[MatthewChase]

We did it. Replaced 2 - 8d batteries with 800 amp hrs of lithium imported from china for $4500 delivered to my door. We also purchased a sigineer 4000 watt inverter. We quadrupled our storage and cut 200 lbs off our battery weight. Everything works great! Yes the price hurt but not as much as the US lithium batt manufacturers would charge. Would have been double.

[BonS]

An additional aspect of Lithium batteries, in general, is that they charge at just over 90% efficiency. A lead acid battery is around 70% efficient.

Also, a good charger will charge at 90% efficiency versus a lesser one at around 70-75% efficiency.

Solar chargers are the same: Good ones at 90%+ and cheap ones around 70%.

If you use a cheap charger with lead acid batteries then you're converting your energy source (gas, diesel, or sunlight) at 50% efficiency. Yuck!

Cheap charger specs often don't mention charge efficiency because they're not proud of it and they hope you'll buy on price alone. It's often hard to read specifications because they leave out their worst attributes.

When looking at solar controller/chargers the usual difference in technology is between PWM (cheap) and MTTP (good) chargers.

[oscarvan]

Originally Posted by MatthewChase

800 amp hrs of lithium imported from china for $4500 delivered to my door

Can you share your source? And I assume that shipped surface and took a while?

[hohenwald48]

Thanks for all the insight. For my particular installation and usage I see flooded LA batteries meeting all my future needs. Still, an interesting thread.

[les.warden]

Anyone know of any data showing issues with these batteries while in an RV, like they’ve shown with e-cigarettes, cell phones, hover-boards, Tesla’s, etc. I’ve watched technical shows that explain what happens when the batteries go into a run-away situation, which causes the flame-on, but wondered if anyone knew or heard of this happening with an RV.