Battery

[hausmutti]

Is this a good match for the Renogy 100W suitcase?

https://www.samsclub.com/sams/durac...e-31dtmagm/prod3590232.ip?xid=plp:product:1:1

 

[rvpopeye]

It depends on how much you plan to draw it down before charging with that 100watt suitcase.
and how much sun you are showing the panels.....
(Gotta get it back to 100% or you wasted your money , ya gonna kill it if you can't)

 

[hausmutti]

It depends on how much you plan to draw it down before charging with that 100watt suitcase.
and how much sun you are showing the panels.....
(Gotta get it back to 100% or you wasted your money , ya gonna kill it if you can't)

Well, I plan to not let it get less than 50% and can also charge it with a regular charger.  Isn't that what I'm supposed to do?

 

[GaRay]

The battery you are looking at is a marine battery and is not rated for deep cycle even though it says it is. Check the label and if it stayed cold cranking amps then it is not a deep cycle battery. A deep cycle battery is rated in amp/hours.

 

[GaRay]

RV pop eye is correct that you need to charge your batteries to 100 percent as often as possible to prolong the life. That process is called equalization and as described in this link: http://lifelinebatteries.com/2015/10/can-i-equalize-agm-batteries/

 

[John TF]

When you do not know anything , its typical that you can make a lot of wrong choices , and spend too much .
THE VERY 1st THING IN SOLAR , get you numbers together , it's called a site survey - what equipment do you want to run ,
then can you get a more efficient device [ as an example a fridge [ RV fridge's are more efficient [ NO COMPRESSOR ] than like house fridge - does have a compressor " motor " ] .
Then add up all your consumption " watt hours & peak amp's .
Using Ohms law , https://en.wikipedia.org/wiki/Ohm's_law .
Now you start planing your system .
Getting something going to help learn , do not spend too much money on stuff ---- as an example https://www.renogy.com/renogy-100-watt-12-volt-monocrystalline-foldable-solar-suitcase/ , close to $3 per watt , do not pay more that $1 per watt , better yet $0.30 to $0.80 per watt -
https://www.wholesalesolar.com/solar-panels
Get a small used battery , even a motorcycle battery - in good condition , then a small low cost solar about 5 amp min. about 50 watt .
This is so you get a feel for , and use metering volts & amp , and especially something that can record amp-hours .
Then when you do start spending some money multi $100 sss .
Not using / charging batteries die very quick , maybe weeks , sometimes lasting a couple yrs.
You should get at least 5-8 yrs. , if not 8-15 yrs. out of a battery bank .
It has been for decades - that try to never use solar for any kind of heating , or running any motor .
Some do not like this site [ because there may be some facts in question , but there are more correct / good info , than there is bad ] http://batteryuniversity.com/
Again if you want to say something bad about the battery site , mention the wrong info , then the correct , seems to me that is what we are trying to do , good info , and if you know of a better battery site , that is user friendly , by all means link it .

 

[John61CT]

There is no "matching" panels to batteries other than size.

Per 100W panel you want at least 50AH, but 100AH handles poor / variable solar conditions better.

Then comes true deep cycling quality.

Deka makes Duracell, and their flooded (FLA) GCs sold at Sam's are fantastic value.

Their AGMs are *not* great, but probably about as good as other generic like Vmax, sold by Renogy. Not what I would call true deep cycle.

The only good quality AGMs in the NA market for that purpose are expensive, like Lifeline, Odyssey, Northstar.

What makes you think you need AGM?

FLA are much more robust, last longer and are cheaper.

 

[hausmutti]

What makes you think you need AGM?

FLA are much more robust,  last longer and are cheaper.

Thinking AGM because of no water maintenance and sealed.  I already have a renogy 100w suitcase.  Plan to use them minimally and plan my usage around what I have.  Lights, charging and using ipad/iphone.  Using an inverter for macbook.  Fan.

 

[John TF]

When you know more , never use a inverter - AC to DC , losses / inefficient / wasting power .
When you need DC - use DC , so then all you need is a DC voltage converter , lots of ways of doing this , but doing this efficiently gets more involved .
In solar the term power optimizers . - https://en.wikipedia.org/wiki/Power_optimizer

DC to DC converter - https://en.wikipedia.org/wiki/DC-to-DC_converter

 

[John61CT]

Thinking AGM because of no water maintenance and sealed.

To me that reason does not justify the far higher expense per year long term. $180-200 for 200+AH gets you excellent FLA GCs, really can't beat that for value.

Once you have the know-how and gear to really take care of them, quality AGM can last as long as FLA, for some over a decade, but that's not likely for a first bank.

If you buy (relatively) cheap AGM, knowing you may need to replace the bank much more often, that is what many do, your van your call.

 

[highdesertranger]

bad info in this thread,
1. equalization is not charging to 100%. equalization is deliberately overcharging to break up sulfation and to equalize the specific gravity in each cell. a lot of AGM batteries will be damaged from equalization. Lifelines are an exception.
2. most RV refrigerators are 2 or 3 way meaning they run on 120v and propane(2way) or 12v, 120v, and propane(3 way). running them off electricity is very inefficient. most 12v compressor refrigerators are very efficient. I have used both and for me there is no comparison a 12v compressor refrigerator beats an RV refrigerator hands down. sun light is free propane is not. highdesertranger

 

[GeorgiePorgie]

 most 12v compressor refrigerators are very efficient.  I have used both and for me there is no comparison a 12v compressor refrigerator beats an RV refrigerator hands down.  sun light is free propane is not.  highdesertranger

Is it possible to get a decent one for around $400.? It would be for one person, so does not have to be too big. Does it use much battery power running 24 hours a day?

 

[John61CT]

Sometimes you see good sales new, but also check Craigslist.

Engels last forever.

 

[Weight]

Back on thread. Yes, that battery would be ok for your existing panel. If it would be ok for your electrical needs is a different question. The best advise here is to be sure to charge the battery.

 

[DLTooley]

Is it possible to get a decent one for around $400.? It would be for one person, so does not have to be too big. Does it use much battery power running 24 hours a day?

Dyers has the Dometic CC-40 for $335.  I believe the difference in this model is that it DOES not have the legendary Danfoss compressor.  My use is intermittent, so it was a no brainer for me.  So far so good.

I use it to freeze water bottles which I then cycle through a traditional cooler which I use as my refrigerator.

 

[Almost There]

I use it to freeze water bottles which I then cycle through a traditional cooler which I use as my refrigerator.

That has been mathematically proven to be the least efficient way of obtaining refrigeration.

Taking water down to freezing temps takes more energy than maintaining a safe refrigerator temperature.

 

[jimindenver]

Have enough solar to cover the power needed to freeze the water and it becomes a none issue. I can put water bottles in my freezer in the morning and have them frozen before nightfall. The batteries did not know they were in there just like they do not know when I turn on the electric water heater which is also considered not efficient.

On the other hand is the efficiency of cost and space. Having the power to take care of business means not having to spend the money on a second high dollar 12 volt fridge and a small cooler just for a few fresh items and water bottles can take up less space.

As always, there is no right or wrong, just people getting their needs met or not.

 

[hausmutti]

The battery you are looking at is a marine battery and is not rated for deep cycle even though it says it is. Check the label and if it stayed cold cranking amps then it is not a deep cycle battery. A deep cycle battery is rated in amp/hours.

How do you know if it's a true deep cycle?  All the batteries seem to have both an ah rating and a cranking rating.

 

[Trebor English]

How do you know if it's a true deep cycle?  All the batteries seem to have both an ah rating and a cranking rating.

Floor scrubbing machines and golf carts use deep cycle batteries.  

Deep cycle batteries are taller to allow more space below the plates.  In normal use there is some shedding of plate material.  More space leaves room for more shedding before it builds up to the level where it short circuits the positive and negative plates.  

Deep cycle batteries will be heavier.  Dual purpose and starter batteries have more thinner plates.  Deep cycle batteries will have fewer thicker plates.  That means more lead and less separator material.

Otherwise it is hard to tell looking at the outside of a battery.  Cutting open the case to use a micrometer to measure plate thickness would not be appreciated by battery store owners.  

In my van I have a single battery for everything.  I got the biggest battery that would fit in the original location, group size 24.  I made a spread sheet to gather information.  I picked the battery that was the heaviest, the most amp hours, the least cold cranking amps.  After doing that I know that the battery I got has a sticker that is different from the same size starter battery.  The sticker may be the only difference.  

The way a battery gets treated makes a huge difference in how long it lasts.  A poorly treated "good" battery might die long before a well treated "bad" battery.  

If you need 50 amp hours then you need a 100 amp hour battery to only discharge 50%.  If you get a 200 amp hour battery that same 50 ah cycle is only 25%.  The battery should last longer.  With the 100 ah battery after it is used a while the capacity may be reduced to 90 amp hours.  Now the 50% limit is 45 amp hours.  Continuing to take 50 amp hours, more than 50%, isn't being nice to the battery.

 

[John61CT]

From a trustworthy maker of true deep cycle batteries, you should be able to get a chart or table with their lab test results, shows

how many lifetime cycles the battery supports, replacement time defined as 20-hour AH capacity falling to 80% or rated

as compared to how deeply the batt is discharged. For comparison purposes, we usually use 50% DoD

The Deka / Duracell GCs are I believe rated around 800 cycles at 50%.

This is what I would consider at the bottom, a minimum starting point, for defining a true deep cycle battery.

Cycling more shallow, say only 20% DoD results in well over a thousand cycles, more deeply maybe only 300.

Further info http://www.pbase.com/mainecruising/deep_cycle_battery