Battle Born Lithium

[CWSWine]

My knowledge of batteries consist of yep it’s dead and replacing it but I have been doing some research on Lithium batteries. So this correct assumption.

Trojan T105 6 volt have 225 amp hours at 6 volts. I have six 6 volt batteries and at 12 volts I have a total of 675 amp hours. Approximately 50 percent of that 675 amp hours is usable so half of 675 is 337 amp hours before charging them or causing any damage to the batteries.

Battle Born Lithium are 12 Volt 100 amp hour each but you can use all that 100 amp hours before charging them. That make 3 battle born batteries 300 usable amp hours before recharging which would be close to the same amount of usable amp hours of the T105.

I could replace my 6 Trojan T105 with 3 Battle Born Lithium and be very close to the same amp hours and don’t have to worry about discharging them below 50%. I could add additional batteries over the next year so to spread the cost over a longer period of time.

Is my logic correct or I’m I missing something? I know the cost of one Lithium battery is almost equal to 6 T105 so I would like to take cost out of the discussion.

[rollondown]

Plus the BB's are lightweight compared to the Trojans, and you would be using a smaller footprint giving yourself some storage back. Additionally, you're saving yourself time by not having to remember monthly maintenance on the Trojans.

[jcussen]

I saved close to 500 lbs by going from 4 8d's to 4 Battle Born's.

[CIDE]

As far as I know a set of batteries should be replaced together, including Lithium. Adding more as you can afford them will have the old batteries dragging down the new ones.

[10 fan]

I think 80% is the safe discharge on lithium I keep reading.

[BillJinOR]

Yes 100% is not a number I’d use 100% if you do get there one time kills them. Most people using them I’ve read are using 70% -80% drawdown. From the articles and posts I’ve read 400 amp hours would be the replacement for what your 675 amp hour lead acid.
When I talked to a solar installer that’s what I was told for my same size array of lead acids

That said I never take my lead acids below 70% left 30% drawdown .. so if you also don’t draw yours down to 50% then you may get by with “only” 300 amp hours

[jcussen]

Battle Born Batteries each have a built in battery management system that will disconnect battery in case of high or low voltages or temps. Battle Born rep told me safe to use 100%, battery will shut off automatically.
Too many people compare them with Lead Acid, completely different animal. BB also gives a full 10 year warranty. They never need to be brought to 100% SOC like Lead Acid.
My 400 amp hours of lithium replaced 1000 amp hours of agm's.

[CWSWine]

This was my impression also that each battery management system would not allow the batteries to discharge to a point that it would damage the batteries and that's why I used the 100% figure.



I also thought with the built-in battery management into each battery I understood that you don't have to replace all them at the same time. That could get expensive if after a couple years you had one bad battery and having to replace all them at the same time. Replacing 6,000 to 8,000 dollars worth of batteries because one failed would be a huge negative in my book

Originally Posted by jcussen

Battle Born Batteries each have a built-in battery management system that will disconnect battery in case of high or low voltages or temps. Battle Born rep told me safe to use 100%, battery will shut off automatically.
Too many people compare them with Lead Acid, completely different animal. BB also gives a full 10 year warranty. They never need to be brought to 100% SOC like Lead Acid.
My 400 amp hours of lithium replaced 1000 amp hours of agm's.

[jcussen]

Originally Posted by CWSWine

This was my impression also that each battery management system would not allow the batteries to discharge to a point that it would damage the batteries and that's why I used the 100% figure.



I also thought with the built-in battery management into each battery I understood that you don't have to replace all them at the same time. That could get expensive if after a couple years you had one bad battery and having to replace all them at the same time. Replacing 6,000 to 8,000 dollars worth of batteries because one failed would be a huge negative in my book

Think you will be happy with them. If you look long term, the very high initial cost is somewhat mitigated by the fact that they should last as long as several sets of lead acid. Agree with you about only needing to replace one battery if it goes bad. Although with the warranty, if it happen in the first 10 years, probably covered.

[CWSWine]

I found this on Battle Born site and I quote:

"A cycle is the process of fully charging and discharging a battery. Typically lead acid batteries cannot be cycled below 50% depth of discharge. If you go lower than 50% you will significantly shorten the lifespan of the battery. Our LFP batteries can be discharged nearly 100% for thousands of cycles without shortening their lifespan."
https://battlebornbatteries.com/what...battery-cycle/

When a battery is discharged, the amount of energy taken out will determine the depth at which it was discharged. For example if you have a 100 amp hour battery and use 50 amp hours you have discharged the battery 50% which means the depth of discharge is 50%. If you took the same battery and discharged it only 20 amp hours or 20% of the battery, your depth of discharge will be 20%. This is an important number to keep in mind, because depending on which type of battery you are using, the number of cycles will be vary based on your depth of discharge.

Most lead acid batteries experience significantly reduced cycle life if they are discharged more than 50%, which can result in less than 300 total cycles. Conversely LIFEPO4 (lithium iron phosphate) batteries can be continually discharged to 100% DOD and there is no long term effect. You can expect to get 3000 cycles or more at this depth of discharge.

https://battlebornbatteries.com/dept...cle-batteries/



That is good news

[CWSWine]

I spent the afternoon searching and can't find if one battery out of 6 goes bad should you place all them or just the bad one.


If you remove the initial cost from the decision I can't seem to find any reason not to switch. Everything has negativities so what are the negatives? Maybe cold temperatures and charging could be one but it it's that cold I'm moving somewhere that's warmer so in my case that wouldn't be negative.

[twinboat]

You can draw lead acid batteries down below 50% . Shorter cycle life but not damage.

From Trojan Battery.

[powercat_ras]

To get the full 100 Amp-hours out of a Battle Born you have to discharge all the way down to 10.0 Volts.

I believe that a more real world design point for use in RVs would be to assume 80 Amp-hours, at that discharge point I believe you would still be at around 11.5 Volts, and would have a better chance of having enough voltage to avoid inverter low voltage shut down.

[paul65k]

I don't think I have seen more mis-information about BB in one place in a long time. Your independent research will yield you much more info than what you are getting here.

Your logic is very sound and will work. You can also add additional Lithium batteries in the future as the management of the charging and discharging is done with logical management vs the loder LA types that only rely on chemical reactions and ARE subject to degradation over time.

Good luck and do NOT take any advice from people on-line about lithium batteries that do not have them themselves or have specific knowledge of a particular brand as BB is not your average lithium approach to RV storage.

Cheers!