Your Experience with LiFePO4 Deep Cycle Batteries?

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winslow

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Joined
Feb 7, 2018
Posts
20
Location
usually BLM or FS land
We are thinking of going with 2 to 4 of these to replace our 8 155-amp hour VMax Tank AGMs:
https://battlebornbatteries.com/shop/12v-lifepo4-deep-cycle-battery/

I am not concerned about battery bank sizing, I have that under control, but I am interested in anyone's experiences charging these with an MPPT controller (It's a Midnight Solar Classic 150). Any experience charging and discharging these batteries, and any pointers to their best treatment would be terrific.

Here's a quick link to the charge controller, too:
http://www.midnitesolar.com/productPhoto.php?product_ID=256&productCatName=Charge%20Controllers%20-%20Classics&productCat_ID=21&sortOrder=1&act=p

Moderators - can you move this to the solar Child Board if that's more appropriate, please? Sorry for the small screw-up!

Thanks in advance!

 
Make sure you can program the charge voltage to the batteries so voltage stays below 14.2V.  I prefer 14.0V so I don't over charge the Lithium.  Also keep your float voltage down around 13.6-13.8V. 

Lithium prefers not to be charged to 100%, 93%-95% is best so keep that in mind.

I have a Morningstar Tristar MPPT-60 and On really bright sunny days I will turn off the controller so I am not sitting there with 14.0 volts and a few amps over charging my batteries. 

I bought the 400AH lithium battery kit from Starlight Solar in Jan 2016 and it has worked very well for us.  Here is a link to more info:  http://www.lithiumrvbattery.com/Lithium_RV_Battery/GBS_100AH_Cells.html

I also have 650watts of solar in 2 large solar panels, wired in parallel, feeding the MPPT controller with about 36V.
 
Contact the manufacturer and ask them what the charging parameters are for their batteries.  We have recently purchased 3-Battle Born LiFePO4 batteries, I contacted Battle Born and they require 14.4V absorption, 13.6 for float and 30 minutes of absorption time charge per battery.  If you have a different brand they may have different parameters so check with them.  If you set your controller settings per the manufacturer's parameters you will not overcharge the batteries, so no concern there. Likely you will not want to equalize for these batteries and you will not need temperature compensation as generally a good idea for lead acid and AGM batteries.
 
Some good information in this current thread:

http://www.rvforum.net/SMF_forum/index.php/topic,109633.0.html

IIUC, the batteries you are considering have internal overcharge protection.


 
So a funny thing happened...we finally got our lithium batteries and I was searching (what else?) charge controller settings for them using a Midnite Classic 150. I was reading the post and thinking, "hey, this guy has the same setup we used to have - same RV...same truck...and the same NAME. WAIT! This is MY POST from way back! LOL.

Anyway - I've finally got the setup in and running. 8 X RecSolar REC315NP 315 watt panels, 8 X Battle Born 10012s, and the Midnite Classic 150. Fired it up today and it was so freaking cool to watch the watts pour in and get sucked up so fast by the lithiums.

Running it as a 48V system, so bulk and absorb voltages set to 14.4 X 4 = 57.6V, 2 hour absorb time, 13.5V float, EQ off of course.

Anybody running numbers like that? Thoughts, results to share?

Thanks!
 
Sheesh, I'm thinking 2 or 3 of the REC n Peak panels and 4 Gc 2's. I would go more but just don't have the room . The 3rd panel would be subject to intermittent partial shading by the roof AC and may or may not be worth installing.  I could possibly raise it to go over a skylight.
Pat
 
We decided to "live small, go big" which is kind of what we're about! We've lived off-grid in different ways for years and after full-timing for a few years have built a "utility trailer" (a trailer that supplies utilities like a set of hookups) to haul around. That's how we have the space for all those panels. :) They are elevated above the roof so vents and such can be under them. Also creates a nice bit of portable shade to keep the rig a bit cooler, of course!

I think we've finally got the ultimate boondocking setup in the works. not quite finished yet but we can see the finish line. While our rather diminutive Outdoors RV 22RBS is our home, we found we needed a bit more space to really "live." We missed our hobbies!

The new trailer adds office space, a den, and 8 feet of garage-like storage. We both work about a job and a half remotely, so everything has to WORK and not make us spend all day futzing around with it.

Today was pretty cloudy here in AZ, but that solar electric system was still full by 10AM. We only have a small-ish residential fridge running on it right now, but that's still encouraging because refrigerators (even 10.5 cubic foot Energy Star compliant ones) are notorious power hogs.

My charge settings seem to be working. I do wish I had more loads on it, though! I really like to use us the power that can't be stored in "wasteful" ways - baking in the toaster over, roasting coffee, running the electric water heater, stuff you'd never really think to use a solar electric system for. :)

Thanks for your replies, all! If there's interest I'd be happy to share more details and even pics. That way you'll know when you see us out in the middle of the desert.  8)
 
winslow said:
So a funny thing happened...we finally got our lithium batteries and I was searching (what else?) charge controller settings for them using a Midnite Classic 150. I was reading the post and thinking, "hey, this guy has the same setup we used to have - same RV...same truck...and the same NAME. WAIT! This is MY POST from way back! LOL.

Anyway - I've finally got the setup in and running. 8 X RecSolar REC315NP 315 watt panels, 8 X Battle Born 10012s, and the Midnite Classic 150. Fired it up today and it was so freaking cool to watch the watts pour in and get sucked up so fast by the lithiums.

Running it as a 48V system, so bulk and absorb voltages set to 14.4 X 4 = 57.6V, 2 hour absorb time, 13.5V float, EQ off of course.

Anybody running numbers like that? Thoughts, results to share?

Thanks!

just out of curiosity, in what configuration did you connect up your panel array ?

secondly, for lead acid, absorb is not a timed event, it depends on SOC. for drop in lithium there is no absorb time, just charge at the required voltage
the on board BMS will handle the rest ( as it should ). bulk/absorb settings should be set at 14.4 V with timing off or set at some large value, float at 13.5 V and Equalize OFF.



 
solarman said:
just out of curiosity, in what configuration did you connect up your panel array ?

4 paralleled sets of 2 panels in series, per the Midnite Solar Classic sizing tool ( http://www.midnitesolar.com/sizingTool/ ). I've still got plenty of headroom on the controller in case I find a need (and a place to put any more panels!)



 
Best place to learn everything about LiPo and solar...Search YouTube for will Prowse...here is an example...

https://m.youtube.com/watch?v=EcVjPap9dkY
 
rbertalotto said:
Best place to learn everything about LiPo and solar...Search YouTube for will Prowse...here is an example...

https://m.youtube.com/watch?v=EcVjPap9dkY

best ? . LOL i would respectfully disagree that statement, most you tube presentations i have seen are questionable
and not authored by a professional engineer. these diy people have a certain amount of experience but lack a professional background
and make many mistakes. some quite dangerous in nature.

Caveat emptor.


 
solarman said:
best ? . LOL i would respectfully disagree that statement, most you tube presentations i have seen are questionable
and not authored by a professional engineer. these diy people have a certain amount of experience but lack a professional background
and make many mistakes. some quite dangerous in nature.

Caveat emptor.
Yes!  Much better to rely on "experts" on the forums. 

I have watched a few of Will Prowse's videos and found he is well worth watching.  Not saying I agree with everything in his videos.

The same with many "experts" on the forum.  I have learned a huge amount (and applied that learning into our RV) in the last 12 years of extensive dry camping and boondocking. 

It is always good to read all sources and sort through what makes sense. 

If you have limited technical background and limited experience with dry camping it is really hard to sort through the garbage and find the accurate info.
 
We have 2 100AH Battle Borns, and I just upgraded the solar to 2 used 250 watt high efficiency panels from Santan Solar. We have a Renogy Rover 30 amp MPPT controller and a 2kW Xantrex Freedom X/C PWS inverter charger.

The day after the solar was completed, I ran the moho plugs out, inverter on overnight to put some drain on the batteries. The next day, the solar panels replaced about 80 AH in 4 or 5 hours in the low February morning sun (done by noon, inverter off).

One thing seemingly seldom mentioned is lithium batteries efficient, high recharge rate. Our Xantrex will put out 100 amps of charge (actually 105 on the Victron monitor), and will recharge the batteries from 100 AH down in an hour on the generator.
 

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