What do you think of lithium batteries without solar on the roof?

[alanmalk]

Originally Posted by Eggscape

We just camp in our trailer and have no need for an inverter so the regular batteries with a bit of solar keeps us going just fine.

Same for us. 220 Ah of lead-acid AGM and one roof panel + one portable has provided sufficient power for every occasion so far.

But that said, I recently purchased a 100 Ah LiFePO4 battery to use with my pontoon boat electric motor. The big advantages for me were more usable power, less weight and a flat voltage discharge curve. There are occasions when I have to carry the battery 200-300 feet to the boat and even my smaller (now 8 years old) AGM is a significant burden. (Unfortunately I also aged 8 years during that time. Don't know how that happened.)

Since the battery doesn't live in the boat I can store it at the 50% recommended discharge and give it a boost the night before a trip, so that weakness is not a problem. Also the rather high 14.4v charging voltage is not a problem since it is charged out of circuit. The low temperature limits are also not a problem when the lakes are frozen.

Would I use LiFePO4 in our trailer? Maybe. Hopefully the current cells will last another year or two and the lithium weaknesses will have been solved.
--
Alan

[Centex]

Originally Posted by dstreight

Lithium Iron Phosphate commonly abbreviated as LFP or LiFePO4.

Thanks, clearly not up to speed with common abbreviations

(LiFePO4 I get, the shortcut "LFP" threw me)

[Brian B-P]

Originally Posted by Centex

Thanks, clearly not up to speed with common abbreviations

They're only common in specific technical fields, primarily electric vehicles. My guess is that even most people with lithium-ion batteries in their RVs don't know which type of lithium-ion battery they have. The Wikipedia page for lithium-ion batteries actually has a decent description of the common types.

[John in Santa Cruz]

Originally Posted by MyronL

Bernie told me the same thing.

Rogelio composited that from a previous desert night photo he had taken at Racetrack Playa where the rocks mysteriously move around when noone is looking.

[kavm]

Originally Posted by Centex

Just for your consideration ....

Re: Battery vent - ETI cannot deliver any trailer without batteries (required for, at a minimum, the emergency 'break-away' brakes which must be functional when they hand-over the trailer). So, if you accept the standard lead-acid battery anticipating later install of your own BattleBorn Lithium, you'll already have that battery-box vapor vent through the back wall of the trailer. IF you order with lithium batteries installed by ETI, do you know if ETI then omits the battery-box vent? I do not know, that'd be something to verify with ETI.
...

Do Lithium batteries require a vent as well? I thought not. However, ETI, I infer, believes that they do require QAI venting (don’t know what that is). I had suggested a Go-Pro (ETI’s lithium battery supplier) 250 Ah battery as an alternative to the 2 100 Ah Go-Pro batteries that ETI is now offering as the max. I heard back that my suggestion was not acceptable due to QAI venting requirements. I do not know enough and did not push back...

I understand that they are still looking into this matter (2 100 Ah max), so hoping for a better outcome.

[NEWYORKHILLBILLY]

Originally Posted by kavm

Do Lithium batteries require a vent as well? I thought not. However, ETI, I infer, believes that they do require QAI venting (don’t know what that is). I had suggested a Go-Pro (ETI’s lithium battery supplier) 250 Ah battery as an alternative to the 2 100 Ah Go-Pro batteries that ETI is now offering as the max. I heard back that my suggestion was not acceptable due to QAI venting requirements. I do not know enough and did not push back...

I understand that they are still looking into this matter (2 100 Ah max), so hoping for a better outcome.

One problem with the go power single 250 AH battery is the 100A (continuous) draw limit. so it would not work with a 1500 watt inverter. where the the two 100ah would give you double a 100 out of each battery for a total 200A draw continuous. witch would run the inverter. This may be a reason that it is not offered. does any one know who is making the go power batteries ?

[kavm]

Originally Posted by NEWYORKHILLBILLY

One problem with the go power single 250 AH battery is the 100A (continuous) draw limit. so it would not work with a 1500 watt inverter. where the the two 100ah would give you double a 100 out of each battery for a total 200A draw continuous. witch would run the inverter. This may be a reason that it is not offered. does any one know who is making the go power batteries ?

Thank you! I did not appreciate that...

[Centex]

Originally Posted by kavm

Do Lithium batteries require a vent as well? I thought not. However, ETI, I infer, believes that they do require QAI venting (don’t know what that is).....

The only Google hit I could get on "QAI" that seems remotely applicable is this: https://qai.org/ (?)

Bottom line, ETI is gonna 'draw the lines' where they want 'em for what they build.

Personally, I don't see an issue with a vented battery box from the factory if that's what ETI insists on doing. If the trailer owner decides they don't need/want it it's easy enough to just remove the tube and 'blind-off' the IMO externally inconspicuous vent screen from the inside (with whatever degree of insulation makes one happy).

[kavm]

Understood. I am still hoping for ETI to offer more than 200 Ah. My understanding that they are still investigating options, though prospects for that do not look very good.

[MyronL]

John, Bernie told me his truck battery lasted 6 years then, just like the two 6v lead acid ones in his Escape trailer they no longer held a charge and needed replacing. Then handed me another ESS (egg salad sandwich.)

[Effie]

Not for everyone, but I know a lot of people here took on some serious challenges, with the high price for Lithium this (or something similar) is probably the way I'm going.

https://www.youtube.com/watch?v=IsvBlQJr7b0

[Brian B-P]

Originally Posted by kavm

... However, ETI, I infer, believes that they do require QAI venting (don’t know what that is).

QAI is the service which Escape uses to certify their products as meeting the requirements of applicable standards, from CSA and perhaps from RVIA. Without looking them up, it is reasonable to assume that these standards are written assuming flooded lead-acid batteries and will require significant venting.

[Brian B-P]

All modern electric cars use some form of lithium-ion battery. As far as I can the only ones with routinely open vents in their battery boxes are the few which are cooled by air flow; however, it is normal for them to have vents which open when a threshold pressure is exceeded.

On the other hand, many amateurs and most suppliers of LFP batteries for RVs believe that the advanced containment and management systems used by automotive manufacturers are unnecessary, presumably assuming that after a billion dollars of development by skilled professionals the result must be silly nonsense that they don't need to bother with.

[NEWYORKHILLBILLY]

Originally Posted by Effie

Not for everyone, but I know a lot of people here took on some serious challenges, with the high price for Lithium this (or something similar) is probably the way I'm going.

I done a lot of research on these builds and for the price its hard to beat. I even ordered the cells from china and stuff to build it.I ended up abandoning the idea Because I could only find one BMS that had a reliable low temp shut off(overkill solar BMS). That had a current limit of 120 amps. Not enough for a inverter. The daily Bms in the video state they have a low temp shut off But test on these units proved otherwise . of course if you don't deal with cold temps this not a problem.

[rubicon327]

Originally Posted by Brian B-P

QAI is the service which Escape uses to certify their products as meeting the requirements of applicable standards, from CSA and perhaps from RVIA. Without looking them up, it is reasonable to assume that these standards are written assuming flooded lead-acid batteries and will require significant venting.

I just posted this on another thread but applicable here...
QAI is an RV certification program:
https://qai.org/z240rv/

It probably defines battery venting requirements based around lead-acid but it may not be current enough to reflect lithium installations that shouldn’t need venting.

[dstreight]

I just use the Victron Smart Battery Sense (Bluetooth) to control the low temperature solar charge cut off. Works perfectly.

[kavm]

Originally Posted by Brian B-P

QAI is the service which Escape uses to certify their products as meeting the requirements of applicable standards, from CSA and perhaps from RVIA. Without looking them up, it is reasonable to assume that these standards are written assuming flooded lead-acid batteries and will require significant venting.

Thank you very much! That clarifies what I heard.

[Effie]

Originally Posted by NEWYORKHILLBILLY

I done a lot of research on these builds and for the price its hard to beat. I even ordered the cells from china and stuff to build it.I ended up abandoning the idea Because I could only find one BMS that had a reliable low temp shut off(overkill solar BMS). That had a current limit of 120 amps. Not enough for a inverter. The daily Bms in the video state they have a low temp shut off But test on these units proved otherwise . of course if you don't deal with cold temps this not a problem.

yes, saw the same thing but I always felt that a 24v system will be easier to work with, cutting the current in half. 24-12v convertors are readily available and are inexpensive.
That said, I'm still a year or two from upgrading my system, things can still evolve.

[gklott]

Originally Posted by rubicon327

I just posted this on another thread but applicable here...
QAI is an RV certification program:
https://qai.org/z240rv/It probably defines battery venting requirements based around lead-acid but it may not be current enough to reflect lithium installations that shouldn’t need venting.

CSA Z240.6.2-14 (2020)/C22.2 §5.23.1, "Ventilation of battery compartments", requires ventilation of all battery compartments.

73/gus

[NEWYORKHILLBILLY]

Originally Posted by dstreight

I just use the Victron Smart Battery Sense (Bluetooth) to control the low temperature solar charge cut off. Works perfectly.

That works great for the solar the charger only . shore power and towing below 32 degrees would be a big problem.. The 7 pin would be punting a charge to the DIY battery. really need a bms with two low temp shut offs. one for to stop charge at 32 degrees and another to stop discharge at 4 degrees. To my knowledge there does not seem to be one available for a do it yourself build. Although there inside the good batteries like battle born and go power.