Lithium battery recommendations for Sprinter build

[Withalligators]

Currently have a Transit connect with a 310w panel, Midnite Solar Classic Kid controller, 2 x crown AGM 6CRV220s, and a Samlex ACR-160 between the starter battery and the deep cycle bank.

I've just picked up a new 4x4 Sprinter, and am planning the solar system, but would like to go lithium. I'd like to go to 400AH to start, but be able to add more later. What are some good recommendations for lithiums? I've seen Battle Born tossed around a lot. I've also seen Prismatics for about 25% cheaper, but they are LiFeMnPO4, what's the difference with that and LiFePO4? What else do you guys recommend, or other things I should consider?

Can I have it so this bank is charged off the alternator like my current setup? Right now the Samlex keeps them isolated unitl one side reaches a nominal voltage and then whichever side is charging then proceeds to charge both. Can you do that with different battery types?

Cheers,
Alex

[karrak]

The Battleborn batteries or something like them are the easiest way to go as they have a fully self contained BMS built in which I think is important for battery life and safety.

If you went down the prismatics road you would have to organise the BMS and do the initial commissioning balance, do you have the technical skills to do this?

Different manufacturers of prismatics put small amounts of other elements like Mn or Y in their batteries to supposedly improve performance. I haven't seem enough information to say how much difference this makes when the batteries are used offgrid or in RVs.

I would say the main three prismatics in use in DIY offgrid systems would be CALB, Winston (Voltronix in the USA) and GBS.

There is a good range of lithium batteries available from here http://www.electriccarpartscompany.c...teries-Lithium

What do you base your figure of 400Ah of battery on?

If you do end up using lithium ion batteries I think it is very worthwhile having an SOC meter like the Victron 700 or 712 which calculate the SOC by measuring the current going into and out of the battery. These are very accurate when used with lithium ion batteries.

Simon

Off grid 24V system, 6x190W Solar Panels, 32x90ah Winston LiFeYPO4 batteries installed April 2013
BMS - Homemade Battery logger github.com/simat/BatteryMonitor/wiki
Latronics 4kW Inverter, homemade MPPT controller

[Withalligators]

I'd like to try and run AC on some of the hotter days of the summer in Socal. I'm a biologist and August in Blythe is atrocious. I'd supplement my solar with generator use when necessary. I'd also have a 12V freezer, separate 12V fridge, and I'd like to run a fairly beefy laptop (Alienware with a thirsty 1080 in it).

I honestly don't know what the initial commissioning balance is. So, off the bat, I do not have the technical skills to do this. Is this something I can learn about and competently do? Or should I stick with a dummy proof solution like BB?

Some of the batteries in the link you provided seem nice.

[morgandc]

Air Conditioning is not realistic on batteries when you do all of the math, get a small AC and small generator for when you need Air.

[Sunking]

I'd like to try and run AC on some of the hotter days of the summer in Socal. I'm a biologist and August in Blythe is atrocious. I'd supplement my solar with generator use when necessary. I'd also have a 12V freezer, separate 12V fridge, and I'd like to run a fairly beefy laptop

Air conditioning is NOT GOING TO HAPPEN and running both a Fridge and Freezer is pushing your luck. If you want AC, park in a RV Park with electric hookups.

I honestly don't know what the initial commissioning balance is. So, off the bat, I do not have the technical skills to do this.

Then you have no business even considering lithium batteries. Not even many experts would use lithium because lead acid are much less expensive, foolproof, and last longer. Stick with using a quality lead acid like Trojan, Rolls, and Crown.

Reconsider your 400 AH capacity. To support 400 AH is going to require 600 to 800 watts of panels. If you drive every day using the alternator you can back on panel wattage or eliminate them all together. Your vehicle alternator can generate more energy in 2 hours than panels can generate in 2 days if you have sun with no shade from sunrise to sunset.

[Withalligators]

Actually, there has been some success with vehicle solar and AC. It's costly, and far from perfect, but doable. And yes, I will have a small generator for any night time use. The roof of the Sprinter looks to be able to do 750-1000w of 250w panels. I was considering a couple of the flexible ones flush mounted to the side as well.

I've successfully used my current setup with 200AH and a (fairly inefficient 12V) freezer, I don't feel like a fridge and double the bank size is pushing my luck. The engine will be run daily, but not for long. And I won't idle it, these modern diesels aren't built for idling with the EGR and swirl valve nonsense. Also, 400AH was my base, I said I'd like to build on it if necessary.

So, can I be pointed towards a resource where I can read up on what I would need to know before I have any business considering lithium batteries. From what I have read, the Battle Borns are as close to user friendly as they come. Not true?

Are the claims of twice the lifespan accurate? They're certainly half the weight, and they're certainly 4x the cost.

[karrak]

If you want to see what can be done with LFP batteries in an RV I suggest you look at posts by reed cundiff.

Your 400Ah battery is going to store ~5200Wh (3.25*4*400, nominal cell voltage*number of cells*capacity). This means you could run an appliance that draws ~4000W for around one hour, the percentage difference is due to power losses in the inverter, battery and a little battery reserve. I would think your twelve volt fridge and freezer would each use ~300Wh-500Wh/day. Interestingly modern full size mains powered inverter fridge/freezers can be as efficient as the small 12/24V units these days.

We live in a climate similar to Socal. Our ~1200W of panels give us on average about ~5000Wh of energy per day in summer and ~3000Wh of energy per day in winter. Our ~10,000Wh of LFP battery storage gives us enough storage to not need a generator. We do all our cooking in summer with electricity and run a standard mains fridge which uses around 1000Wh/day and lighting, computers etc. We do not run an air conditioner.

You should try to do an energy budget to work out the requirements of your power system. Try to differentiate between loads that only need to be run during the day when there is sunshine and loads that will need battery storage.

I would think that the humidity is quite low in Socal in summer so you might be able to stay cool by using fans or evaporative coolers.

I assume you currently have an inverter, if so what size is it?

You are right in saying that the Battleborns are as close to user friendly as they come. You can treat them as a drop in replacement for LA batteries with the following proviso. As they have very low internal impedance/resistance and can accept large amounts of charge current they can overheat alternators. This should only be true with older vehicles.

How much experience have you had with electronics? Have you had any experience with Radio Controlled equipment and charging lithium ion batteries with hobby chargers?

LFP batteries should last at least ten years while cycling at least 50% per day. Our LFP battery is nearly 5 years old and shows no signs of any change in performance, we are only cycling about 20% of battery capacity per day through the battery.

Another big plus with LFP batteries is that you can run power hungry equipment with a small battery because of there low impedance/resistance and high energy efficiency.

This is a good white paper on balancing lithium ion batteries. You can use a hobby charger to do the initial balance charge. There is lots of good information on that website. If you want to look at BMSs I would look at the Orion Jr from the US or the Zeva and Batrium BMSs from Australia.

Simon

Off grid 24V system, 6x190W Solar Panels, 32x90ah Winston LiFeYPO4 batteries installed April 2013
BMS - Homemade Battery logger github.com/simat/BatteryMonitor/wiki
Latronics 4kW Inverter, homemade MPPT controller

[reed cundiff]

Karrak mentioned us above.

We have approximately the same solar and LFP on fifth wheel as does Karrak. We can run A/C for 4 to 5 hours as combination of battery and solar before we drop below 60% SOC with 5th wheel setup and perhaps an hour with our 2002 Roadtrek. Running A/C all night is not possible. We could increase panels from 1400 to 2000 W and LFP battery suite to 19 kW-hrs but as full time RVers, we choose not to go where it is hot and humid: mountain west for summer and Yucat

[reed cundiff]

[QUOTE=reed cundiff;n370136]Karrak mentioned us above.

We have approximately the same solar and LFP on fifth wheel as does Karrak. We can run A/C for 4 to 5 hours as combination of battery and solar before we drop below 60% SOC with 5th wheel setup and perhaps an hour with our 2002 Roadtrek. Running A/C all night is not possible. We could increase panels from 1400 to 2000 W and LFP battery suite to 19 kW-hrs and install mini-split A/C and run 24 hoursbut as full time RVers, we choose not to go where it is hot and humid: mountain west for summer and Yucatan for winter. Therefore, we have not made this simple but expensive

[Mike90250]

Sorry Reed, the forum software truncates posts after odd characters found in non-windows systems. usually the's apostrophe's the culprit, but quote marks from apple & mac gear trips it up too.

[Sunking]

Are the claims of twice the lifespan accurate? They're certainly half the weight, and they're certainly 4x the cost.

Greatly exaggerated and mostly lies. Just one mistake and they are boat anchors, make a rookie mistake and you have fire. The truth is in the battery manufacture specs and not the gizmo manufacture. Read this thread and IGNORE the Gullible one. Battery manufacture specs are given. A123 Systems makes the best Lithium Ion battery period and only claims 1000 or so cycles. for $5/wh.

Trojan Solar Premium Line specs state 2000 cycles to 50% DOD, and Solar Premium Line to 3500 cycles to 50% DOD. Both are 1/5 to 1/3 the cost of A123 batteries and 1/2 of Chi-Com junk batteries like Calb, Winston, and Sinopoly. Trojan batteries come with 3 to 10 year warranties depending on product line. Chi-Coms warranty is a poke in the eye with a sharp stick.

Here is Trojan Battery Cycle Life charts. In an RV limit daily discharge to 30% of total capacity.

[Withalligators]

Excellent. Thank you for some real world info.

My experience with lithium, at it's most complex, is probably disassembling laptop batteries for 18650s and charging them while checking the voltage to make sure they didn't overcharge. Now with cheap circuit protected 18650s and smart chargers (even if you're not getting a perfect recharge) I just use those in my flashlights. I'm competent at soldering and have fixed the TVs, PSUs, etc, but I largely rely on forums to ask questions for diagnosis. I have a poor working knowledge of electrical theory and I don't pretend otherwise. That's why I ask folks smarter than I on forums.

I realize it would be nigh on impossible to run AC all night. I'm investing a lot in quality insulation. I plan on having a small, quiet generator for night when I need AC to cool the place down. Then I'll seal it off and hopefully fall asleep for the night with a fan. I just need to get it below 95ish.

I'll read that paper you linked. Thanks!

Cheers,
Alex

EDIT: I think we posted at the same time, I will also read your link Sunking. Thanks!

[zamboni]

I'm living fulltime in a small 5th wheel and using only solar, no propane or genny. Very tight budget, exclusively boondocking. My GF and i talk about downsizing to a van ALL the time, so i think about it a lot. We have plenty of friends in vans. Check my system details in signature.

Straight up: Give up on the A/C. You're in a fscking van, dude. If you want to live like you're in a house, get an RV rig and all the attendant BS that comes with it. Vandwelling is about exchanging certain luxuries for certain freedoms. What are you even going to use, a window unit? Where? They weigh like 50 lbs. and you have to do something with the condensate. No roof-mounted unit will be efficient enough and they'll all shade your panels.

Speaking of panels, please do not waste money on the flexible ones. Bending a panel means it can never be aimed the right direction, and sticking it to a metal surface means it will always be too hot. Get panels mounted in frames and put them on the roof with an air gap for cooling. Give up on "stealth". Everybody knows whats going on with a damn sprinter van parked overnight.

I have run a window A/C unit with our system; it was enough to make a very crappy stationary summer in the southeast comfortable, but our rig is better insulated (rebuilt) than some stick-built houses. And of course, traveling with it is ridiculous (we don't; returned it). With your metal skin and attendant thermal shorts to the interior, "good insulation" in your van won't equal what we have in our rig. Not bragging, just trying to cut the crap and save you some hassle.

You already have experience with vandwelling but LFP is a pretty sizeable challenge. For a bank the size you're talking about, the weight savings isn't so huge that LFP is "do or die" vs. regular lead-acid. And the cost/risk is so much larger. Most of your current equipment just isn't capable of taking care of LFP batteries - accuracy requirements go up an order of magnitude. My charge controller is a Midnitesolar Classic, and i had to buy the add-on Whizbang Jr. module so it would measure voltage accurately enough to stop charge without over-charging the cells. I had to buy a new multimeter just so i could measure accurately enough.

Consider sticking with lead-acid batteries, and putting some money into more/better panels or a genny. Make more use of the energy during the day and keep the batteries happy and full so they last a long time. If your current fridge isn't very good, money is better spent on getting a more efficient unit than on upgrading to LFP.

Drop-ins like battleborn are appealing, but i have a really skeptical view of them: You're trusting this company to handle all the "BMS" functions for you inside their "black box". LFP should last you 10 years...will Batlleborn be around then? Will they take care of you if your cells are toast in 5 years? Hard to say. This may not be you -- but the kind of people who are eager to drop a few k on new tech are also not the kind of people to make a fuss in 2 years when the tech doesn't live up to it's claims (because they're busy throwing money at newer tech).

Sorry not in a sugar-coating mood tonight, but let me just sum it up this way: I have LFP. I like it because it can do awesome things. But i also enjoy the challenge of it, and i'm specifically trying to live in a way which is a challenge (all solar RV). That creates a lot of non-freedoms for me. Lots of things i can't do, issues that come up, time and money spent working on the system instead of, you know, working for a living. I put in the LFP last April and i've spent most of this January re-doing it. Is your van a project, or is it a means to an end?



- Jerud
------------------------------------------------------------
1220W array (4x 305W Astronergy panels @ 48V)
1000Ah LFP house bank (5P4S HiPower 200Ah cells)
MPPT solar charge controller (MidniteSolar Classic 150)
2800W PSW Inverter (Magnum MS2812)
ME-RC, Trimetric, and JLD404
2001 Fleetwood Prowler 5th wheel 25 foot, self-rebuilt

https://www.livesmallridefree.com

[Withalligators]

I'm going to play AC by ear. I'm currently insulating and I'll see how a fan works to combat the heat in a better insulated rig than both my previous. If my work locale demands it, I'll put a removable window unit in the back and run it off a genny at night.

My van is my house. I've been full timing for years, so I do appreciate the warnings about making my daily driver a project. I don't want that. I converted my daily driver / house cummins to run on veggie and it was more trouble than it was worth in downtime.

[zamboni]

Your stated A/C strategy sounds solid. The least hassle, most flexible, and lowest added cost, albeit the least satisfying.

Never been to SoCal but i reckon the climate is tolerable while sleeping (maybe with a fan); you only need A/C while the sun's up, right? It's not like the southeast where you're sweating in your bed. I'd like to hear other's opinions on it... but you could up-size your array solely to run the A/C direct-from-panels. Hand to mouth electricity, so to speak. You'd not be able to use A/C except at midday, but so long as the panels are reliably making say 500W at that time they can keep the A/C humming with no net depletion of the batteries. Note i say making 500W not rated. That probably means at least 700 rated watts. More, if you try to use the flexible ones. Getting that much wattage to fit your 6.5' wide roof (which length van do you have?), without shading from items already up there may be tricky. I forget what the Kid is capable of, but you may have to up-size the charge controller to handle the extra current from paralleling 7+ 12V panels. I've seen truck campers with 700W on the roof...might be possible for you. At these wattages MPPT starts to make sense, but that's another cost adder. MPPT would pair well with transverse-mounted 24V panels: They shade your roof and conduct very little heat to it so they help keep it cool. Even if you're not running A/C. You could maybe get by with 2x 325W/24V panels, which should fit in under 7' of roof (no shadows!). You'd have enough power coming in even on overcast days to use the laptop a little bit. It's not cheap...but it's definitely cheaper than lithium and you were apparently okay with that so... : )

I'm definitely describing an "imbalanced" system. I think most will say the excess panel wattage and/or MPPT is wasted money if your battery stays small. But if it gets you something you want -- 3 hours of midday A/C -- then maybe not? Depends on your priorities and your $ situation. The main risks i see are behavioral, not technical: You could suck your batteries dry pretty quickly if you flake out and leave the A/C on. There would also be a big temptation to keep running "just a little longer" on battery even though you're not making enough watts to support it, which could make for chronically undercharged batteries. Both would result in early battery failure. I dunno, maybe plug the A/C into a light timer? (One that's rated for 15a?). Also don't forget panels will add nontrivial weight to your rig, maybe 100lbs. including racking. Vans tend to always be marginal on cargo vs. axle ratings...

I'm still wondering where that A/C is going to live when not needed. You're gonna get sick of whacking into it the other 11 months of the year. I've been watching this Noria product for a couple years now...they keep saying it'll be out soon but it hasn't launched yet. Currently projected for spring 2018. It's a 5k BTU window A/C but at what looks like maybe 1/3 the size of a typical unit. Designed for one-step insert / remove. Not officially for mobile use of course...but i would love to give one of those a whirl. I could actually store it in the RV without rearranging my entire life around the damn thing.

If you have equipment to buy, you've got until Feb. 6 before meathead's tariffs become effective and prices jump.


We also ran waste vegetable oil for about 2 years. WVO is totally workable if you're stationary, but doing it while mobile is a slow death. Glad i did it; gladder that i stopped. Sounds like we both know how it can be a drag when your 'lifestyle' gets in the way of your 'life'.


- Jerud
------------------------------------------------------------
1220W array (4x 305W Astronergy panels @ 48V)
1000Ah LFP house bank (5P4S HiPower 200Ah cells)
MPPT solar charge controller (MidniteSolar Classic 150)
2800W PSW Inverter (Magnum MS2812)
ME-RC, Trimetric, and JLD404
2001 Fleetwood Prowler 5th wheel 25 foot, self-rebuilt

https://www.livesmallridefree.com