batteries

[billcf7]

Originally Posted by TomC_AZ

Batteries are like a religion so do some serious research for your needs and ability to spend money now and in the future. This is a little long and I apologize, but hopefully it sheds some light on the topic and makes sense and helps!

Like others question, what type of RV and use case do you have for the battery?

Unfortunately its not as easy as is 6v better than 12v.

Food for thought.
A wet or GEL cell battery can only be used to 50% of its rated AH/WH, anything beyond this you start to do damage to it. This reduces life. Weather and other environmental characteristics also impact the life, such as high heat like we have here in AZ or mainly driving on long bumpy dirt roads for boondocking.

Then there is how long do you want to have power without using some other source such as shore power/generator etc. or even solar, i.e. night time. If you look at wet/GEL cell 6v will usually last longer but you need multiples as the trailer is 12v.

There are weight concerns as well.

So real world example of two good brands and batteries, the use case I am using is this. I want to have a usable 300AH/3849WH of battery to be able to run an inverter and multiple things at once while boondock camping.

To accomplish this I have a few options below, as mentioned to keep it simple I am going to stay with 12v options for now. For the record however there are however 6v, 12v, 24v, and even some 48v options out there. Note, to stop those trying to rip this apart this is only an example, there are different brands, capabilities/features, and costs for each type of battery so again this is where research and requirements come in.

If using wet/GEL
Trojan (as previously mentioned)
https://advantagebatteries.com/shop/...7-gel-battery/
Would need 6 of these (100ah-50% =50ah 300/50=6)
Each of these weight 62lbs for a total of 372lbs (62*6)
Each cost $302, $302*6=$1812
Lifespan (mounted upright only) in AZ (if lucky) about 4yrs, would need to buy at least two sets over 10years equaling $3624+.


If using Lithium
Enduro Power Battery
https://www.enduropowerbatteries.com...39956252491940
Would need 1 of these (300ah/3849wh)
Each weight 63lbs for a total of 63lbs
Each cost $1699 for a total of $1699
Lifespan (mounted anywhere and in any position) 10+years, would only need to buy one.

Even after the first purchase the Lithium is a cheaper proposition than wet/GEL when comparing two good battery brands.

For brand snobs, even a single larger Battleborn would be cheaper than wet/GEL.

There are many other examples like this, even the Trojan 265ah battery will cost more on first purchase due to needing multiples for equal usable power.

I hope this helps someone.

Tom Very well put This is what Ive been saying to every battery question in this forum

[garywilson]

Originally Posted by Rnightengale

is it better to add 2 6 volt batteries or 2 12 volt. which will give the best as Far as usage

---------------
So.... did you get an answer you liked in response to the simple question you asked?

How about just 'depends'? ��

[CampNow]

I've experienced the following pros and cons using two 6v batteries in series and two 12v batteries in parallel (not at the same time--lol!) in several TT's:

While under high load, two 6v batteries in series will incur higher voltage drop (due to higher internal resistance) vs. two 12v batteries in parallel. This assumes, of course, that the two 6v's in series have the same overall ah rating at 12v as the two 12v in parallel. This voltage drop can be severe enough to cause an inverter to activate its low-voltage cut-off (typically <11v) and shut-down prematurely. End result, with high loads (>100a) you may have access to less ah's with two 6v batteries in series vs. two 12v batteries in parallel.

As previously mentioned, most 6v batteries are true deep-cycle batteries. Most 12v "RV" batteries are not true deep cycle batteries, even though their typically labeled as "RV/deep cycle" batteries. 6v deep-cycle batteries (i.e., GC2's) will generally last longer in severe-duty scenarios where the batteries are repeatedly discharged to 50%, charged to 90-100%, then discharged to 50%, often.

As for using lifepo4's, IMO, if you have space/weight concerns and high current needs (>100a), hands-down, lifepo4's are the better choice, even in-spite of the high cost. For those with no space/weight concerns and generally low-power requirements (<50a), IMO AGM's offers the best ROI. YMMV.

[billcf7]

Go lithium and end all your headaches

[Yooper906]

Originally Posted by billcf7

Go lithium and end all your headaches

This is the part I don't understand, or I would have bought lithium batteries 2 years ago.

"But you don’t want to charge your battery in temperatures below 32 degrees Fahrenheit"

I take my camper to sled dog races and ice fishing derbies so guaranteed it's going to be below freezing. Would I need to have a battery warmer of some type? Sometimes I can run off a generator, sometimes not. I like the idea of lithium batteries, hate to buy expensive ones that I can't charge in cold weather.
Hope this makes sense to someone?

[RogerR]

You can buy Lithium batteries with internal heaters. One of the very nice things is that Lithium batteries don't emit hydrogen, spill acid or fumes so they can be kept inside where there is some source of heat.

I don't winter camp and love the weight difference so carrying inside for the winter will be wonderful vs. my lead wet cell battery means a lot in my lithium vs. lead acid battery. Another plus is that we are getting close to our GVW rating.

[billcf7]

Do you not heat your trailer. Some manufacturers have heated batteries. Only charge them when they are above freezing. The BMS will not allow them to be changed below freezing. Can still be discharged down to about-10 C

[CampNow]

Originally Posted by Yooper906

This is the part I don't understand, or I would have bought lithium batteries 2 years ago.

"But you don’t want to charge your battery in temperatures below 32 degrees Fahrenheit"

I take my camper to sled dog races and ice fishing derbies so guaranteed it's going to be below freezing. Would I need to have a battery warmer of some type? Sometimes I can run off a generator, sometimes not. I like the idea of lithium batteries, hate to buy expensive ones that I can't charge in cold weather.
Hope this makes sense to someone?

Several options:

1. Relocate your batteries to an interior, heated area of your camper. Perfectly safe---lifepo4 cells don't off-gas.
2. Place the batteries inside an insulated enclosure and warm the interior with 12v heating pads wired through a thermostat.
3. Purchase a Battleborn or Lifeblue lifepo4 battery with the optional internal heater.
4. Continue using lead-cell batteries.

[TomC_AZ]

Something else to remember is that they cannot be charged when THEIR internal temp is below 32deg F. This is different/separate from the outside air temp especially when inside which I think is where a lot of people get hung up on that spec. Basically this is due to the way it all works, chemistry wise, when using the battery even a little the electrons move which also creates small levels of internal heat. So hypothetically it could be 0deg F outside and if your constantly running the heater, water pump, water heater and have a TV or radio on the battery might still take charge. Again as said before the BMS (small computer inside the battery) will stop it when it senses that the battery is too cold, then will start again when warmed up.

There are some cost reasons not to buy them but also there are some to buy them as well and the same goes with Led Acid/GEL. It all comes down to what you feel you can afford etc. its always the dollars and cents in the end. Walmart does have a good warranty with their batteries that are at any store. Lithium you would have to wait for something to arrive in the mail and they cannot be over nighted. But the good ones have a great warranty and will prob never see a problem anyway.