Battery Issue

[sonofcy]

Originally Posted by Woogiebear

Hmmmmm...... So this battery isn’t a deep cycle? (Sorry, prettt ignorant about batteries but I’m learning). I thought it was a regular battery because I didn’t see anything about amp hours. But the rv guy told me this would work fine.

Sad but true, just because it says deep cycle doesn't mean it really is. If it also says anything about cranking amps, marine cranking amps, reserve something then it's NOT a true deep cycle. A true deep cycle will ONLY state amp hours. Also if it's lead acid, you should only use about 1/2 of it's amp hours. Two American made brands are Trojan and Crown. I use 2 Trojan T105's that last me 6 hours (1/3 used) in a power failure last winter and we have a residential fridge but it's max draw is only 480 watts.

[xrated]

Originally Posted by Ccsluke

Somewhat concerned about the recommendation of 6v batteries.
If you have room for two batteries, go with deep cycle 12 volt and parallel them. (Connect positive to positive and negative to negative). Then you will truly have double battery power. With 6v batteries you would have to take two batteries and hook them up in series (positive from one battery to negative of the other battery, then your 12 volts would connect to the other two + & - terminals. but when you do this, you’re gaining voltage, not power. Two 6 volt batteries have to wired in series in order to give you the 12 volts needed. BEST OPTION, HANDS DOWN, IS TWO 12volt batteries.

The highlighted part above ^^^^ is true......But.....if they only provide less than 100 amps each (and they usually do), then you still don't have as much amp hours as two 6V GC batteries hooked in series for the 12V. My Trojan T105s are rated at 225 AH.

[sonofcy]

Originally Posted by Ccsluke

Somewhat concerned about the recommendation of 6v batteries.
If you have room for two batteries, go with deep cycle 12 volt and parallel them. (Connect positive to positive and negative to negative). Then you will truly have double battery power. With 6v batteries you would have to take two batteries and hook them up in series (positive from one battery to negative of the other battery, then your 12 volts would connect to the other two + & - terminals. but when you do this, you’re gaining voltage, not power. Two 6 volt batteries have to wired in series in order to give you the 12 volts needed. BEST OPTION, HANDS DOWN, IS TWO 12volt batteries.

The 2 6V GC batteries are better. They will provide 225AH (112 usable max). I replaced 2 12V 75(37 usable) AH that came with the coach for a gain of 307%.
The 6V and 12V batteries are about the same physical size so the plates in the 6V are about double the size. Example, the Trojan 12V largest size at 66lbs is 130AH therefore two in parallel will give you 260AH vs the 225AH of the pair of 6V GC batteries. Keep in mind the 50% draw down rule and it's really 130 vs 112.5 or 17.5 AH for $100 more in cost? I don't know all the technical details but there must be a reason the majority of RV solar systems use T105's. It might be something to do with charging parameters or something else.

[MarkEHansen]

I took a quick look at the 12V battery (although it wasn't specified, I assume you're talking about the Trojan SC S225). It's 130AH at a 20-hour rate. This means that with two 12v batteries, you would get 260 AH. While with two 6V (Duracell SLI6V225S) you would get a total of 250AH at a 20-hour rate.

Both batteries cost about the same.

Although the 12v have the edge in power (10 additional AH), I think the scales still lean toward the 6V batteries, as with their heavier plates, they will take more charge/discharge cycles and provide that power longer than their 12v counterparts.

YMMV.

[sonofcy]

Consider the life of a golf cart battery, those batteries have to be tough both mechanically and electrically. Consider that there are half the plates in roughly the same enclosure and same weight. IIRC there is 4 lbs difference between 1 6V and a 12V (62 vs 66)

[Cfilipiak]

I had a similar issues when I purchased a new travel trailer that had two 12v batteries. I replaced them with two 6v Trojan 125+ Batteries and I have not had any problem since.

[jdarwin]

https://www.interstatebatteries.com/products/31-mhd


According to Interstate Batteries web site, this battery is for large trucks and RVs used to start engines.

[travelin texans]

Originally Posted by jdarwin

https://www.interstatebatteries.com/products/31-mhd


According to Interstate Batteries web site, this battery is for large trucks and RVs used to start engines.

That is definitely NOT the battery you need for a rv house battery, you have absolutely no need for all the "cranking amps". Would be great for your tow vehicle.
As said a true rv deep cycle battery will list amp hours not cranking amps.

[JRTJH]

Maybe think about it this way:

Electron flow from a battery is what produces "amps". Whether they are cranking amps or discharge amps.....

Electrons flow from the "SURFACE" of the lead plates. To get "high amps" the manufacturers use numerous thin plates with holes drilled in them (to increase surface area). This makes the battery more "fragile" but allows maximum electron flow on demand. This makes the battery prone to damage when deeply discharged and makes it not a "good" deep cycle type battery.

Golf Cart batteries have no need to "produce high amps". The plates are thicker, fewer in number and don't have "modifications to increase surface area" (no holes drilled in them). That makes the battery more heavy duty, able to survive deeper discharge cycles without damage, less potential to "sulfate" (build up a coating on the lead surface that prevents electrons from attaching)).

In other words, it's sort of like comparing a sports car with a diesel tractor. One will "go fast" and the other will "pull your sports car to hell and back". Same with "high cranking amp batteries" and "deep cycle batteries".

[jimborokz]

Originally Posted by JRTJH

Maybe think about it this way:

Electron flow from a battery is what produces "amps". Whether they are cranking amps or discharge amps.....

Electrons flow from the "SURFACE" of the lead plates. To get "high amps" the manufacturers use numerous thin plates with holes drilled in them (to increase surface area). This makes the battery more "fragile" but allows maximum electron flow on demand. This makes the battery prone to damage when deeply discharged and makes it not a "good" deep cycle type battery.

Golf Cart batteries have no need to "produce high amps". The plates are thicker, fewer in number and don't have "modifications to increase surface area" (no holes drilled in them). That makes the battery more heavy duty, able to survive deeper discharge cycles without damage, less potential to "sulfate" (build up a coating on the lead surface that prevents electrons from attaching)).

In other words, it's sort of like comparing a sports car with a diesel tractor. One will "go fast" and the other will "pull your sports car to hell and back". Same with "high cranking amp batteries" and "deep cycle batteries".

The last paragraph is the perfect analogy.