RV Batteries - Lithium as Option

obiwancanoli wrote:

My rig came with 4-6V batteries, each 115 min at 75 Amps, 220 AH@ 20Hr.

If I connect Lithium in parallel, do I double available amps?

Are Lithium's all 12V, and if so, would I need only two to replace what I currently have?

What changes, if any, must I make to existing systems in order to accommodate Lithium batteries?

Ok so you currently have 440 amp hours 220 usable. Close to what I have.
Note that that 50% usable is for DEEP CYCLE and other types might not be so forgiving of a "DEEP discharge" (Some batteries only 15-20% of the power is usable (Starting) about 25 for MARINE/deep cycle)

Lithium. Some types are good for close to 100% of contained power

Next. WIll I need 2: I can not answer that it all depends on that amp hour. YOu need more usable amp hours. Just to "example" you currentlyu have 4 GC-2. Well you could use two 4D and geet about the same powere.. and a hernia (joking on that) as they are 2x as heavy as the GC-2. (My Deka G-20's I can not install by myself.. the Interstate's they replaced I could 10 amp hours more in the Deka was just enough to cross the line)

How to figure amp hours for a multi-battery system

If you wire them in series like this

-{6v}+==-{6v}+== 12 volt to house. You do not add the VOLTS together (See how I got to 12 volts) not the amp hours and I might add this is where the Belief that all batteries need to be identical comes from. IN the pair. they do need to be identical

But when you wire them this way

-{12V}+
-{12V}+

(That is parallel) Then you add amp hours, not voltage.

DO you need two.. Again that depends on the battereries. Lithium types are lighter so you can put one BIGGER battery in or two smaller ones or even 4 or 6 depending on the size of the battery and the battery box.. The more amp hours the better. I will give you the caution over just counting batteries later.

Do I need to do anything different charging.
Depends on who you buy from Top end Lithium battery firms build assemblies. not just batteries but batteries with built in charge controllers and for the most part you can treat these normally. You may need to change your converter to one designed for LIthium however. (I would recommend it)


Why just saying I have 1-2-3-4-5-6 12 volt batteries is NOT enough info.

Where as with GC-2 6 Volt Golf car we can say 220 Amp hours give or take 10 and that's close enough for most use.... We can not do that with 12's here is why

Group 24 is about 70-75 AH
Groups 27 and 29 100 more or less
Group 31 120-130
4D and 8D about 220

All different sizes.

I have some as low as 5 amp hours here Still 12 volt (jump starters are often in the 7-25 amp hour range)

So the only IMPORTANT numbers when designing are
Maximum level of discharge (50% for GC-2 Flooded wet)
20 hr Amp Hour rating (220 for the above)

Size and shape of the space to stick 'em in.

You want to maximize the amp hours and not exceed the space