I'm still liking my wet cell deep cycle batteries. Getting 6 years out of each set. I know the Lithiums have some benefits and some folks are installing them together with the necessary chargers, but I'm not sold. I like the simpler, easy, not have worry about routes in life that has a lot less initial cost. At the same time I know not to go so inexpensive that create problems another direction. I've seen some problems when, folks not knowing better, going a bit too far on the skinny. What say you Cummins Meat heads.......can't be racist so I'll say, chicken heads too? 

Used to sell marine equipment. The lithium is the way to go if you find yourself running out of power or have the money to not worry about upfront costs and can afford to get the price/watthour/age benefit. A properly cycled and maintained lithium battery will last indefinitely. Keep them 20-75% SOC and it will likely outlast you. Do full 0-100% cycles and you will get 3000 cycles or so, or 8-9 years doing a full cycle daily. 

 

80% of a "cycle" is between ~80-100% SOC, the other ~20% is from 0-20%. 20-80 effectively accounts for about 0.1% of a cycle.

 

Guys with lithium on their boats for trolling would run for a weekend and still have charge left, the guys with 36v of lead acid were getting about 8-10 hours. They would also put out effectively full power (amperage) until they were discharged where lead acid is more of a decline in amps relative to the SOC.

 

Just be sure to buy batteries with built in protection if you do. Don't trust the charging circuitry. Look for batteries with internal battery management circuitry.

 

Oh, and don't let them get super cold. They like temperatures we like, should probably figure out a way to keep them warm if you plan to park the RV in freezing temps. They make heat blankets for them. 

Edited January 16, 20214 yr by That Guy

Some come with heat blankets that keep themselves at optimum temps, I think some are built in the battery sides. It's nice to have the automated limiter so you don't go crazy running down too far. That's a nice feature.

 

What kind of charge regime do Lithiums need, or can I use my Xantrax marine charger already installed in my RV?

 

Also would one 100 AH Lithium be able to replace my two deep cycle batteries as far as use?

 

I admit I am still afraid of the issue with fire in an RV though.

I’m still not sold on them. I do have room to mount 3 of them without losing storage and them staying warm... but I’m not spending 3K for 300AH. Even 2 of them would provide more usable AH than my 300AH 6V’s, but at twice the cost. I am just not convicted they will last 2x as long. 
 

I got over 10 years on my last pair of lifeline 6V’s and my current pair are going on their 8th season and I don’t notice any degradation. 
 

I am adding solar to my 5th wheel this winter and that will be adequate for how I camp. I’ll probably do 1-2 170W panels. 

3 hours ago, JAG1 said:

Some come with heat blankets that keep themselves at optimum temps, I think some are built in the battery sides. It's nice to have the automated limiter so you don't go crazy running down too far. That's a nice feature.

 

What kind of charge regime do Lithiums need, or can I use my Xantrax marine charger already installed in my RV?

 

Also would one 100 AH Lithium be able to replace my two deep cycle batteries as far as use?

 

I admit I am still afraid of the issue with fire in an RV though.

Im unsure about the Xantrax, but probably not. Lead acid and NiCd/NiMh can charge with constant current. They will just dissipate the overcharge as heat. That's why you can leave them on charge. Its not the most effective way, but it works. Lead acid can also be charged at constant voltage if they haven't been completely drained. 

 

Lithium likes to charge up to ~60% at a constant current and then constant voltage from 60-100. 
 

People are used to experiencing phones and laptops with lithium and that has sort of given it a bad rap. People dont charge them properly and they are being hammered when charging so as to decrease charge time and being pushed to the absolute limits so they can claim the longest life. And they still last at least 2 years under the worst possible conditions. Lithium likes to be stored at a mid charge state, not full and damn sure not empty. That's how fires start. Once the voltage starts to drop, the lithium will tear through the insulator and end up causing a short. Try to charge with that short and it can cause a meltdown.

 

That said, lithium has a passive discharge rate of like 1% per year. NiCd/NiMh is like 5% per month, lead acid is closer to 10% per month. 

 

Lead acid likes to stay topped off, lest they fail prematurely. They actually cycle in almost inverse to the lithium. You could discharge an infinite number of times from 100-95% and it would last a very long time, or discharge to 50% and get about 1000-1500 cycles. 

 

24 minutes ago, AH64ID said:

I’m still not sold on them. I do have room to mount 3 of them without losing storage and them staying warm... but I’m not spending 3K for 300AH. Even 2 of them would provide more usable AH than my 300AH 6V’s, but at twice the cost. I am just not convicted they will last 2x as long. 
 

I got over 10 years on my last pair of lifeline 6V’s and my current pair are going on their 8th season and I don’t notice any degradation. 
 

I am adding solar to my 5th wheel this winter and that will be adequate for how I camp. I’ll probably do 1-2 170W panels. 

They last a lot more than 2x if taken care of. They have almost exclusively swapped to lithium backup batteries for the signal and communication systems on the railroads. They started putting them in about 15 years ago and had only had very isolated failures so far. A lot of the original batch is still in service. Ideally, there is a C&S site about every 10 miles on the railroad with a signal block in the middle of that. Norfolk Southern has about 20k miles of track. It adds up quick. The lead acid they would have to replace about every 5 years on average, due only partially to cycles, mostly due to either super deep draws or vibration. Trains vibrate everything terribly within about 50 feet of the tracks. With lithium, vibration isn't as much of a killer.

 

 

When doing accounting, lithium is about 1/3 the cost of lead acid when depreciated out over the life of the system. But I fully understand, 3k is a lot of up front cost to eat particularly for what amounts to a hobby. I don't have any lithium setups, and probably won't for the foreseeable future. I don't even typically use AGM unless its like my wave runner or something. I have worked on a few of those systems, and even have a small collection to play with. Lead acid is a lot more forgiving in so many aspects, but lithium is more energy dense and lasts longer. 

 

Below is some useful charts to illustrate, not necessarily to take as gospel, but to show an example. They have taken lithium to 10's of thousands of cycles to see how they behave at certain points and still maintained above 70% capacity. An impossible feat with lead acid.

 

Lithium    

 

I know, the up front cost is what kills it. I can go visit IBMobile at camp, eat all his food and go round trip for less than the cost of one lithium battery.

Still using standard old lead acid batteries. Still very capable of equalize charging. Heck, the house batteries here are over 10 years old and still going. There is eight 6V batteries tied in 24V bank of 2 banks of batteries. I've had this system since 1997 that's 24 years of service. I've also only replaced ONE set of batteries. Its no different that a RV. I'm self sustaining power system just the house doesn't roll on axles bnut fix to the ground. Just a bigger system and supplies 30A at 120VAC. (4,000 watt inverter).

 

As for the batteries I always tend to sway away from AGM or Lithium batteries because of the sealed nature. You have to remember my batteries are in service 24 hours a day and 7 days a week. Not like a RV that you park and not live in daily. I still to this day do equalize charging and top of my electrolytes. Being my batter to replace all eight is roughly 4,800 to 5,200 dollars on today market. I've got 820 amp hours worth of batteries at 24 Volts.

 

This system runs 24 hours and 7 days a week. Constantly charging and discharging supplying the house with power daily. These battery are TRUE deep cycle batteries designed for home power centers. For those that are "weekend warriors" can't compare usage being this system NEVER shuts down. This system power everything in the house except - heat pump & A/C, drier, stove and oven. Loads are too big for my small 4kW inverter.

 

This system has been running for 24 years now powering my house daily!

 

Matter of fact just last week I just topped off with distilled water and ran a 2 hour equalize charge and she is ready for the next month of power outages and burn outs. Average power outage here is 12 to 24 hours. Longest was 17 days. So for battery supplied RV or homes I do have this all dialed in...

 

 

Mike I used to get Trojan 6 volt batteries for 125 each. They can't be that much mike.

I paid $4,800.00 for eight 6V batteries. These are not the small one each battery is roughly 125 pounds.

 

Edited January 18, 20214 yr by Mopar1973Man

2 hours ago, Mopar1973Man said:

I paid $4,800.00 for eight 6V batteries. These are not the small one each battery is roughly 125 pounds.

 

Now I see says the blind man....

 

$4800 would pay for about 3 years of my PGE electric bill with cutting and splitten' wood every year. I only need about 2.5 to 3 cords each year. I built my home going overboard on insulation and modified my wood stove to pour out the heat like the old ones did back in the day. With your solar system your getting 10-11 years on that same money which is cool. It's a lot colder there than out on the wet side too.

Still in all the quiet power is always welcome being I've been living off a battery power house for 24 years now. I can say that for sure nothing wrong with good old lead acid batteries. After killing my first set at about 12 to 13 years I learn never ignore the electrolyte level. I ran at least 1 cell on every battery low enough to expose some of the plate material and ruined the batteries in a short order. It really does help to have exact charging voltages and how to properly charge them. What is the max discharge voltage allowed etc. All these values are now programmed into the Inverter and it continues to charge and discharge those batteries daily. 

 

Solar wise those are eight 50 watt panels. Eventually I would like to upgrade them to a bigger set of 1,500 watts or more. That would do so much better in the winter time with the short amount of daylight. Still in all even the way I built the system its still a great fall back power source. 

 

Back to the batteries... The simple fact I can equalize charge and pull the sulphation back into the plates and change it back to lead is priceless. This is something a AGM battery can't do. Being that both AGM and Lithium batteries are sealed they can never be equalize charged. Being I've got lead acid batteries in the truck I can simple just pull the batteries and hook them up to the solar power bank and equalize them too as part of the solar bank. Hence my long life span on my truck batteries too. My last set I will admit I ran dead several times to 0.00 Volts (Lights left on in the cab) I mean dead so it shorten the last set to about 8 years and quit. I'm now on my 2nd set of Walmart batteries. 

The charger in my camper has an equalize phase which I like. I'm really not ready to switch to Lithium Batteries as I did acquire some fear of them from the stories on fire even though weight is a large factor when carrying a truck camper.

 

RVs' go up very fast.

On 1/18/2021 at 7:10 AM, Mopar1973Man said:

Being that both AGM and Lithium batteries are sealed they can never be equalize charged.

AGM is true, Lithium strongly depends on the individual battery. Some do and some don't. It's not that expensive per battery for a company to add it in, but you may be right that many don't.

On 1/16/2021 at 3:56 PM, AH64ID said:

I’m still not sold on them. I do have room to mount 3 of them without losing storage and them staying warm... but I’m not spending 3K for 300AH. Even 2 of them would provide more usable AH than my 300AH 6V’s, but at twice the cost. I am just not convicted they will last 2x as long. 
 

I got over 10 years on my last pair of lifeline 6V’s and my current pair are going on their 8th season and I don’t notice any degradation. 
 

I am adding solar to my 5th wheel this winter and that will be adequate for how I camp. I’ll probably do 1-2 170W panels. 

 

 

you can get 4 280 amp hour cells and a BMS for $500 and make your own 12v lithium battery.  It’s easier than the ground wire mod.  I’m building my second battery now and I’ll say lithium lives up to the hype in my book. 

3 hours ago, trailhead said:

 

you can get 4 280 amp hour cells and a BMS for $500 and make your own 12v lithium battery.  It’s easier than the ground wire mod.  I’m building my second battery now and I’ll say lithium lives up to the hype in my book. 

Interesting, what is a BMS?

Battery Management System

 

Depending on how nice it is, it may just protect the battery from over charge/discharge or may handle the charging of the individual cells internally and monitor temps. Ideally, it keeps one from going into thermal runaway (fires) or damaging the battery in other ways.

Went camping Saturday night. Temps got down to 15° and we kept the 5th wheel around 58-60° overnight. Batteries weren’t quite full at bedtime, was using the inverter a bit, but they were still at 12.77V the next morning. Still very happy with my 7 year old AGM 6V batteries. 

Edited January 26, 20214 yr by AH64ID

 

Batteries can store for a very long time with no issues as long as they are fully charged. Now working the batteries every day 24 hours a day and 7 days a week constantly discharging and recharging for 10 years way different story. Since my house system power nearly everything and system runs 24 hours a day 7 days a week. This is where the lead acid comes to the top better because for something like I have and power my house day in and out 24 hours a day 7 days a week. 

 

Weekend warriors, well yeah that looks impressive but storage time and not being used is cheating a bit. Any battery can sit in storage and not be used for long period with a full charge. Just like my 1996 Dodge pickup siting in the yard for months at a time not being driven. It the fact of working the batteries every day, charging and discharging every day for 10 years. This battery system is never shutdown or stops or get storage time like a RV. Different story now. 7 years old and weekend warrior used vs. everyday home power 24/7 for 10 years. I've got way more charge and discharge cycles for sure. 

 

 

 

 

Edited January 26, 20214 yr by Mopar1973Man

On the flip side I've seen many a battery fail from lack of use, it's not an easy life either. A standard lead acid battery discharges at approx 5% per month, so in 4 months the voltage on a good battery could be down below 12.5V and dropping fast in the winter. 

 

Very true too. 

38 minutes ago, AH64ID said:

On the flip side I've seen many a battery fail from lack of use, it's not an easy life either. A standard lead acid battery discharges at approx 5% per month, so in 4 months the voltage on a good battery could be down below 12.5V and dropping fast in the winter. 

 

My RV charger will automatically recharge the batteries every 30 days or so depending on resting voltage. RV does sit mostly during cold months. Also if I unplug the shore power cord and then when reconnected it will recharge the batteries. If I use a small probe I can push and hold a recessed button for 5 seconds and it goes into equalize mode for boiling off the sulfates. I think it goes to around 15.5 volts during that phase. I really like that charger made by Xantrax and is one of the good older versions. Only problem Is one of the two paralleled batteries doesn't lose as much electrolyte as the other battery which could mean factory wiring is not so good. 

 

It's amazing how it's so important to the factory that they convince you, that you never want buy another new RV.. What a f.o.r.d. it was when new. 17 years later..... still finding shortcut workmanshipt. Spelled correct here.