Lithium Batteries

[Jim Bennett]

Originally Posted by Old Fulica

It is very tempting but at these prices I will wait for them to come down in price. I would think that this is the same technology use in the Prius, Tesla, etc. not the technology used in hoverboards and Samsungs.

This is what I plan to do. I just spent $500 on two AGMs, and figure if I wait 5 or so years, the lithiums will have dropped way more than that in cost.

[Dave Walter]

I spent about $800 a year ago for a lithium battery for my ebike. They are great batteries for packing a lot of power in a small package. As Brian mentioned, the chemistry of these batteries is much different than those starting fires in cell phones.

[Old Fulica]

Originally Posted by gocamp

These Rv'ers enjoying them for Approx 4 years now
Lithium Ion Batteries for RVs | Technomadia

Interesting. Thanks.

[dab]

Originally Posted by jhardie

I bought 400ah lithium batteries to support 4 100w solar panels I had AM Solar(Springfield, OR) install for me on my 2014 5.0TA and so far they are living up to my expectations. Basically zero maintinence free, way lighter to carry and don't take a lot of space under u-shaped dinette. I had them installed when AM Solar was just getting into the lithium battery systems. I basically didn't want to mess with the wet cell batteries and I wanted to be able to camp wherever my travels took me. Like I said it's a great way to go if you can.

I assume that you changed the A/C converter in your trailer to be compatible with charging lithium chemistry? Or do you just rely on the solar panel? We are considering selling our Casita and moving to an Escape, and I'd like to go with lithium as original equipment.

Dave
Boise, ID

[Brian B-P]

Originally Posted by Old Fulica

I would think that this is the same technology use in the Prius, Tesla, etc. not the technology used in hoverboards and Samsungs.

That's a reasonble guess... but it's not so.

Most of the Prius (and other Toyota hybrid vehicle) batteries on the road are not lithium (of any kind) at all - they are nickel metal hydride (NiMH). Toyota and other manufacturers have used NiMH for reliability - they routinely last the life of the car, even if that's hundreds of thousands kilometres of taxi service - and they manage them very conservatively, never fully charging or discharging the battery. At Toyota, only some very recent hybrids use lithium batteries.

Tesla (like other all-electric car manufacturers) does use lithium batteries... but Tesla does indeed use cells like those found in small electronic devices and toys such as those "hoverboards". They don't burn up, but that is due to the use of proper battery management systems. The lithium batteries from Lithionics are available with battery managment systems - hopefully good ones.

The batteries from Lithionics use lithium ion iron phosphate chemistry, unlike the batteries in a Tesla or a mobile electronic device.

Lead-acid batteries are pretty easy to manage compared to lithium, so if going to lithium batteries, it's time to pay attention to the electronics.

[Brian B-P]

Originally Posted by jhardie

I bought 400ah lithium batteries to support 4 100w solar panels I had AM Solar(Springfield, OR) install for me on my 2014 5.0TA...

Originally Posted by dab

I assume that you changed the A/C converter in your trailer to be compatible with charging lithium chemistry?

The lithium batteries currently offered by AM Solar are sold as part of a complete system, which they call a "battery bank". These systems do not include a charger, and are expected to be used with various charging sources, including solar, alternator (vehicle), generator & shore power (or "grid"). The included battery management system should keep the charger from harming the batteries, but it would still make sense to eliminate (by configuration) any "equaliztion" cycle from the charger, and adjust the charging voltage if possible. The batteries use lithium iron phosphate (LiFePO4) chemistry, not the chemistry used in electric cars and mobile electronics.

[jhardie]

On my system I have a Magnum 2000w converter so when plugged into shore power then the inverter converts it to 12v for storage in the Lithium batteries. On the other hand the inverter also converts 12v to 120v for my plugs etc. The original AC Converter is wired into the system but the Magnum takes care of any converting.

[Brian B-P]

Originally Posted by jhardie

The original AC Converter is wired into the system but the Magnum takes care of any converting.

I assume that this means one of the Magnum Energy brand mobile inverter chargers from Sensata - either the ME2012 or the sine-wave output MS2000.

I don't see any reference to lithium batteries in the MS2000 manual, but it does apparently have a remote control panel which has some ability to change the charging program.

Originally Posted by jhardie

The original AC Converter is wired into the system but the Magnum takes care of any converting.

My guess is that the AC power distrbution panel (circuit breaker box) and DC power distribution panel (fuse box) of the original WFCO are still used... but if the WFCO converter is still wired in, how do you handle two devices both converting 120 V AC shore power to 12 V DC and connected to the same battery and loads? Or is the WFCO converter not actually connected to AC power?

[jhardie]

The Magnum was the MS2000 Pure Sine Inverter paired with a ME-RC50 Remote for Magnum Inverters. If I remember correctly the the AC Power panel was wired to the 12v and 120v plugs and acted to prevent overload with it's circuit breakers. Also a Charge controller that provides a "boost" from the solar panels to the batteries along with a monitor that is programable.

[paulk]

As previously noted, Lithium Iron Phosphate Batteries are very safe. Practically speaking, they won't sustain burning even if you happened to set them on fire. The Lithium Cobalt Oxide batteries are the ones that are constantly getting in the news for catching on fire, but even then it's in the range of 1/1,000,000 or less for good ones.

Progressive Dynamics makes a Lithium Iron Phosphate converter/charger, if you so choose.

I'm going deep cycle AGMs built by a quality manufacturer, probably Trojan Reliant batteries. I would only go for Lithium Ion Batteries if I were full timing it instead of occasional use. The reason is not cost. Led acid batteries of all types LOVE to be kept as close to 100% charged as possible. Lithium Ion batteries HATE to be kept at 100% charge. My trailer will sit in my driveway 95% of the time waiting for me to take a trip. That kind of usage pattern would be detrimental to a lithium ion battery, but not for a led acid battery. Full timers would keep their batteries below 100% more often, and can make better use of the benefits of lithium ion batteries. In order to make electric vehicle batteries work for 8 years, manufactures typically only charge/discharge them between 30% to 80% and increase that range as the batteries get old to maintain driving range. At the end of their lifespan the batteries are being charged/discharged over their entire range, and they decay quickly after reaching that point. RVs don't get such high quality charging hardware that monitors the batteries over their entire lifetime, so you will probably not get the advertised lifespan if you end up buying lithium ion batteries. I'm not even sure anyone in the RV industry allows to you set your maximum charge level.

A lot of huff is made about the fact that led acid batteries hate to be discharged below 50%. This is true, but misleading for an occasional users like myself. Even if you were to swing a quality deep cycle AGM from 100% down to 20% repeatedly, you'd still get in the low hundreds of charge cycles. I'm very unlikely to drop down to 20% charge hundreds of times over the life of the batteries, so my batteries will die more from old age rather than from calcification due to overdrawing.

Wet led acid batteries have a high internal resistance. This makes them waste a certain amount of energy during charging and discharging, which makes them less suitable to solar installations where total energy is limited. AGMs, like lithium ion batteries, have low internal resistance in the low amperage ranges that I expect to operate. Problem solved.

Led acid batteries take a long time to charge from 80% to 100%. That's ok with me. I'll be getting solar cells which can provide a nice trickle charge during the day. If I remember correctly, AGMs have less of an issue in this area due to their low internal resistance.

For those of you who use your trailer in cold temperatures, Lithium ion batteries HATE to be charged in temperatures below freezing. Advanced lithium ion battery enclosures often include a heating blanket that gets activated before charging the batteries. In the RV space, this is often omitted.

Most of the information you read on the web regarding lithium ion batteries seems to be from marketers either directly or indirectly and contrasts lithium ion batteries vs lower quality wet cell batteries instead of AGMs, which are much better. I’ve seen mention the “fact” that lithium ion batteries are better since you can use them over a wider charge/discharge range, however as I mentioned above, that is not really true if you want the full rated life of the lithium ion batteries.

When you look at the specs for lithium ion batteries, you’ll see that the true amp hour rating of lithium ion batteries roughly equals that of led acid batteries per unit of volume. Lithium batteries seem roughly, and I’m picking a number here without going back to re-compute it, about 40% lighter per amp hour. So, if weight is your deciding factor, then yes, lithium ion batteries are a good choice, but not per unit volume. One of the more deceitful things I’ve seen is that some lithium ion battery manufacturers rate their batteries in “led acid equivalent” amp hours. Basically, these lithium ion battery manufactures double their amp hour rating because they say you shouldn’t draw your led acid batteries down below 50%.

For a long term real world view:
Living the Lithium Lifestyle – 3.5 Year Lithium RV Battery Update | Technomadia

[fudge_brownie]

Very nice report, I appreciate the time you spent putting this togeter and the content is very good. It appears your summary is: Use flooded batteries unless you are full timing or have some other exceptional need. This seems to be a pretty small audience?

Originally Posted by paulk

I'm not even sure anyone in the RV industry allows to you set your maximum charge level.

Some of us on the forum have been espousing the maximum charge levels on flooded batteries. I would say not without frequent ridicule. If one reads the technical information it is quite clear these have charge rates that exceed 15 volts.

It seems those using Blue Sky or Bogart Engineering solar controllers will achieve the recommended charge levels.

[rbryan4]

Thanks Paul for the excellent summary. I completely agree with your conclusions.

[Old Fulica]

Originally Posted by paulk

I'm going deep cycle AGMs built by a quality manufacturer, probably Trojan Reliant batteries.

Wow! Great report Paul. My urge to buy lithium seems to have subsided

[alanmalk]

Originally Posted by paulk

...

I'm going deep cycle AGMs built by a quality manufacturer, probably Trojan Reliant batteries. ...

My experiences with AGMs:

5 years ago purchased a good quality (Odyssey, re-branded as Sears) size 27 AGM deep cycle battery for my fishing motor. I have been charging it with a homemade constant voltage/constant current charger, usually giving it a long trickle charge at the end. It has preformed wonderfully for long days of fishing and shows no sign of aging.

1.5 years ago installed a pair of size 31 AGM 12v batteries (Odyssey/Sears) in parallel in my Escape 21. They are charged by the Escape standard solar charger and the WFCO converter. I never them a second thought, much less worry about maintenance. Since they always seem 90% or above I expect a long lifetime from these batteries. (Prior to installation I checked the self-discharge between the 2 parallel batteries and it stabilized around 5 ma after a week. So a month of self-discharge can be replaced by 5 minutes of solar charging - too trivial to worry about.)

Bottom line: Worth the extra cost for me!

--
Alan

[Brian B-P]

Thanks, Paul, for an excellent overview of the battery situation, and some very sensible conclusions.

Originally Posted by paulk

Progressive Dynamics makes a Lithium Iron Phosphate converter/charger, if you so choose.

That's the PD9100L, the "lithium" version of the common PD9100 series converter/chargers. Judging from the manual, it appears to simply be a regular 9100, but with the charge voltage factory-adjusted to 14.6 V (higher than for lead-acid), the voltages for all phases set to the same value (effectively eliminating the separate float phase), and omitting the equalization phase (which would be unsuitable).

Even with a lithium-specific charger, a lithium battery also requires a battery management system (which Progressive Dynamics refers to as "balancing circuits") to protect each cell individually from overcharging or completely discharging; that's usually packaged with the battery.

This "lithium" charging voltage is really high for "12-volt" equipment in the trailer, and the charger would continue at this level all of the time (as a converter). This is higher than a car's charging system ever produces, and I would not want that for some stuff in the trailer, such as the furnace fan. Our Atwood furnace is definitely excessively loud and sounds like it is being driven too hard when our normal PD 9100 converter goes into equalization mode.

I think if I used a lithium battery in a trailer, I would either:

• isolate the loads from the battery with a voltage regulator (which would provide 13 V or less to the trailer's circuits), or
• use a charging voltage of no more than 14.2 volts (giving up battery capacity).

Any charger that is sufficiently programmable could work for the lithium batteries, by setting all voltages to the same value, and setting that value up to a suitable level.

[Brian B-P]

Originally Posted by paulk

A lot of huff is made about the fact that led acid batteries hate to be discharged below 50%. This is true, but misleading for an occasional users like myself. Even if you were to swing a quality deep cycle AGM from 100% down to 20% repeatedly, you'd still get in the low hundreds of charge cycles. I'm very unlikely to drop down to 20% charge hundreds of times over the life of the batteries, so my batteries will die more from old age rather than from calcification due to overdrawing.

I think this is an excellent point, and it is supported by lots of test data from reputable battery manufacturers.

Originally Posted by paulk

When you look at the specs for lithium ion batteries, you’ll see that the true amp hour rating of lithium ion batteries roughly equals that of led acid batteries per unit of volume. Lithium batteries seem roughly, and I’m picking a number here without going back to re-compute it, about 40% lighter per amp hour. So, if weight is your deciding factor, then yes, lithium ion batteries are a good choice, but not per unit volume. One of the more deceitful things I’ve seen is that some lithium ion battery manufacturers rate their batteries in “led acid equivalent” amp hours. Basically, these lithium ion battery manufactures double their amp hour rating because they say you shouldn’t draw your led acid batteries down below 50%.

I've noticed that - both the energy density and the discharge assumption. The "usuable" capacity for lithium for a given case size is assumed to be much higher (because the allowed discharge level is much lower) than for lead-acid, but if you use this and leave the lithium battery discharged in storage, you risk ruining it in a single event. This has proven to be a concern for electric car owners, who need to be careful to charge before extended storage.

[Brian B-P]

Originally Posted by paulk

For those of you who use your trailer in cold temperatures, Lithium ion batteries HATE to be charged in temperatures below freezing. Advanced lithium ion battery enclosures often include a heating blanket that gets activated before charging the batteries. In the RV space, this is often omitted.

This would be an issue for me, and I think it would be for anyone with batteries not in the interior of the trailer who ever camps with freezing temperatures overnight. I note that Lithionics (the manufacturer of the batteries mentioned earlier in this thread) includes this on each spec sheet:

Lithium batteries are not designed for use in sub-freezing temperatures.

[paulk]

Originally Posted by fudge_brownie

Some of us on the forum have been espousing the maximum charge levels on flooded batteries. I would say not without frequent ridicule. If one reads the technical information it is quite clear these have charge rates that exceed 15 volts.

We're using charge level to mean different things. I'm using it in terms of a percentage of capacity (eg 80%), and you are using it as voltage.

Charging voltage is another good reason to get AGMs. The reason flooded cell batteries need a higher charge voltage is that they have internal resistance, which needs to be overcome. That isn't a problem with AGMs since they have very low internal resistance. Using 15 volts on an AGM would damage it, so manufacturers just use the AGM charging profile by default as a safety measure. You can solve most of the problem by buying/installing a different charge controller, or getting AGMs. I like the AGM route since it's also superior for other reasons. Cost is really the only concern with AGMs, but you'll be paying either way if you want to correct this.

[SFDavis50]

Originally Posted by paulk

A

Wet lead acid batteries have a high internal resistance. This makes them waste a certain amount of energy during charging and discharging, which makes them less suitable to solar installations where total energy is limited. AGMs, like lithium ion batteries, have low internal resistance in the low amperage ranges that I expect to operate. Problem solved.

Thank you for the interesting analysis. I have been wondering about this issue also. I now will change my iPhone charging behavior as I have always been obsessive about keeping it fully charged.

My understanding is that Escape won't put in AGM batteries so if I want to change them to AGM I will have a near new set of flooded batteries. Is there much of a market for almost new batteries? (Personally I would never buy a used battery from anyone I didn't know very well and trust.) With me it may be a moot point as the sun is always shining in Colorado and the pine bark beetle has killed off the tall pines in many of the NF campgrounds I will use.
I would probably pay the extra cost of two 6v or even 2 12v AGM batteries but not sure if I would change out the flooded if I already had them.
I would be very interested in a dual 12v AGM set up option as they would be in the rear bench on the 5.0 TA as that will further offset some of the pin weight as well as provide more amps.

[paulk]

Originally Posted by SFDavis50

My understanding is that Escape won't put in AGM batteries so if I want to change them to AGM I will have a near new set of flooded batteries. Is there much of a market for almost new batteries? (Personally I would never buy a used battery from anyone I didn't know very well and trust.) With me it may be a moot point as the sun is always shining in Colorado and the pine bark beetle has killed off the tall pines in many of the NF campgrounds I will use.
I would probably pay the extra cost of two 6v or even 2 12v AGM batteries but not sure if I would change out the flooded if I already had them.
I would be very interested in a dual 12v AGM set up option as they would be in the rear bench on the 5.0 TA as that will further offset some of the pin weight as well as provide more amps.

I haven't asked ETI about their position on AGMs yet. I'll either just leave them with ETI to avoid disposing of them later, hopefully for a credit but probably not, or use their wet cell lead acid batteries for a few years and swap when they die. ETI doesn't use high end batteries, so it's not like it's a huge monitary waste.

There are 6 volt deep cycle golf cart AGMs (Trojan T105−AGM as one example), which is what I'm getting, eventually. If you want 2 batteries, series is probably the way to go.

http://www.trojanbattery.com/product/t105-agm/