Renogy solar 100W kit installed

[squash]

Freshly installed the panel today! Can I get some recommendations on battery to buy? My requirements are running a small 12V fan at night while sleeping, powering my fantastic fan on an as needed basis, a small Mr Coffee and possibly a small LED TV. Would a single 12V battery suffice? Perhaps an AGM? The van will be used once or twice a week for overnight sleeping. thanks.

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I was thinking of this Walmart Special : or 2 of them?

http://www.walmart.com/ip/37530484

 

[highdesertranger]

you need to add up what you are planning on using. with a 100 watt panel you want about a 100ah battery which would give you around 50ah of useable power max, until the battery must be recharged. so add everything up and go from there. that coffee maker is going to suck some juice. is the led tv 12v or do you have to run it through an invertor? need more info. highdesertranger

 

[wagoneer]

You are on the right path, I would recommend a larger panel if you can afford it AND mass is underrated I use 2 big 6 volt AGM's and a 240 panel, perfect for me. I should be getting about 125 AH.

 

[RogueRV2]

A 100AH AGM might handle the draw from a coffee maker, but it is an expensive battery, and there would not be much power left to run anything else that day. And AGM's are very expensive. Any 12vdc heater or hot plate sucks waaaay toooo much juice to be used unless you've have a larger battery bank as the huge draw, greater than 20% of the AH rating, can do damage to a standard flooded deep cycle. There are other ways to boil water. I know my coffee is important. I'd use a small propane single burner stove instead. One can cook anything on those as well. They are the type that run off a 1 pound cylinder.

Given the low cost of 2 Costco flooded batteries, at about $89 each, I'd go with those and plan on getting another 100 watt panel in the near future. The reason it is best to have about 1 watt of panel for every 1AH of battery is that the panel array should be large enough to recharge the battery, ideally as near to 100% by the next afternoon, and certainly within one week, to avoid sulfating and prematurely shortening battery life. One can buy a true deep cycle 12vdc 100AH battery at NAPA, but it be about $110, and if you decided to install another panel within the next year or so, you'd want to buy more 2 deep cycles at that time, that are of the same age and the first battery should not be used with the newer batteries. The old battery will mess up how the charge controller reads and charges the newer battery, thus shortening the newer battery's life. The rule of thumb is that batteries should be not different in age, more than 6 months different in age, and be of the same type and AH rating.

Do not buy a 'Marine' or 'RV' battery or any battery that has a cold cranking amp rating. These are starting batteries, and in the case of the Marine /RV battery, those are a dual purpose starting battery with a reserve to allow it to provide a *limited* amount of power for accessories. Used in a solar system, they last only about a year or so. Of course, if your tight on money after purchasing this panel, perhaps a single 12vdc deep cycle battery is all that you can afford at this time.

 

[RogueRV2]

Also, in a very confined area, flooded lead acid batteries can produce enough hydrogen gas during the equalization phase that there is a risk of an explosion. You could use a deep cycle gel cell battery instead of the AGM, cause it's cheaper, but I'd rather have the good old reliable and cost effective flooded lead acid type, put them in a sturdy plastic box, and vent it to the outside. I'll move my lead acid batteries into the toilet/'bathroom area to keep them warm during the extreme cold of Montana winters or where the temperature is near freezing, by gutting the cabinet under the sink. Batteries have only half of their capacity at 32F than at they do at 70F. Shut the door and let them off gas like everything else in there with the vent cracked open a bit.

 

[squash]

RogueRV2, can you provide me with some links for 12V 100AH batteries (true deep cycle)....I have Walmarts, Costcos and maybe a Napa within driving range. I searched their websites but it becomes overwhelming with a billion different choices. I really appreciate your input! My budget is $200 max right now on battery power btw....down the road, I may add additional panels.

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How about these guys: sealed Lead Acid's....maybe 2 or even 3 of them in parallel? Price is right.


http://www.walmart.com/ip/UPG-85980-D5722-Sealed-Lead-Acid-Batteries-12V-35-AH-UB12350/21618851

 

[LeeRevell]

Squash, do some Googling and see if you have anything like "Battery Source" or "Batteries Plus" nearby - they are local to me and sell the golf cart batteries, but I haven't checked them for true 12V Deep Cycle yet.

 

[squash]

LeeRevell, there is a BatteryPlus just 30 miles from me! I'll stop by during the week and see what they have. Thanks!

 

[RogueRV2]

Sorry I don't have the link to the Costco 6 volt golf cart batteries, but Costco should still carry these and I've found that the are the least expensive in my area, or about $89 with only a $9 core charge X 2 = $196. Just give them a call before heading down there. There could also be a $50 membership you'd have to buy making the NAPA golf cart battery a slightly better choice. Our NAPA carries a 'knock off' made by Trojan, similar to the T-105, but in a black case, yet these are $120+ and the core charge is $15 X 2 = $270. Costco batts are $196 + $50 for the membership = $246. The number of cycles the Costco version is reportedly capable of is 700, but the Trojan T-105 does a bit better with 750 cycles.

Of course I recommend the best one can afford, and if I could swing it, I go for the best for it's size, the Trojan T-105RE, $160 or for a larger 400 watt system , the Trojan L16RE $350+. The L16's last much longer the T-105's or any other golf cart sized battery, but the cost per amp hour is about 50% higher. The L16 can last between 8 and 11 years. The payback in made up in time or longevity.


BTW, I'm going to upgrade my so called 30 amp Renolgy CC cause it does not have a temperature sensor that would seriously be needed in colder climates. It'll be replaced by the Morningstar Sun Saver Duo. This one also allows one to customize the voltage settings to account for an aging battery's performance and needs, and it will allow me to charge a second set of marine type batteries that I already have as back ups. I'm carrying a total of 5 batteries. The dual charging capability is not just for the starting battery, but will allow one to use whatever old battery they happen to find cheap or free and add it to the system. I see an advantage and potential to scab on what ever battery with this feature, or best yet, the ability to add panels, 2 hopefully, and another pair of newer deep cycles. It's a true 25 amp CC good for 440 watts. The Renology 30 amp is good for only 360 watts, or only 20 amps, not 30amps as advertised.

RogueRV2, can you provide me with some links for 12V 100AH batteries (true deep cycle)....I have Walmarts, Costcos and maybe a Napa within driving range. I searched their websites but it becomes overwhelming with a billion different choices. I really appreciate your input! My budget is $200 max right now on battery power btw....down the road, I may add additional panels.

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How about these guys: sealed Lead Acid's....maybe 2 or even 3 of them in parallel? Price is right.


http://www.walmart.com/ip/UPG-85980-D5722-Sealed-Lead-Acid-Batteries-12V-35-AH-UB12350/21618851

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[VanLifeCrisis]

if you have sams club you can get guest pass and grab 2 golf cart batteries by duracell for 215 ah or so, 230$ with core charge etc.
they are labelled duracell but are rebranded deka batteries, true deep cycle batts

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http://m.samsclub.com/ip/duracell-golf-car-battery-group-size-gc2/prod3590228

 

[squash]

What do you think of this battery for my 100W solar kit:

http://www.batterystuff.com/batteries/upc-telecom/UB12750-45821.html

Price is right $128....It's AGM deep cycle and 75Ah too. I'm really trying to avoid wet battery where I'll need vent lines. I'm only going to need it to sustain a small LED Tv, LED lights and a few other small items while out in the wild. Any experience out there with this battery or company? Thanks in advance

 

[amwbox]

Trojan has an excellent battery sizing calculator:

http://www.batterysizingcalculator.com/

Just using it to ballpark the loads you listed, I got about 50 AH per day. Of course, you'll need to be able to recharge those 50 AH each day...

 

[LeeRevell]

And, you want to discharge the battery no more than 50%, so that 75AH battery is too small. Need minimum of 100AH if using 50AH per day.

 

[highdesertranger]

amwbox thanks for that link. I have been to their web site but missed that. highdesertranger

 

[amwbox]

amwbox thanks for that link. I have been to their web site but missed that. highdesertranger

No prob. Eye opener about how much more efficient 24 volt is. Effectively doubles your AH. Too bad the stupid cars all run on 12 volt. :s

Almost makes we want two battery banks. Just a small 12 volt deep cycle to tie to the engine and run 12 volt loads...and for the solar a big 24 volt bank for the heavy lifting.

 

[squash]

Mr. Indecision (me) bit the bullet and bought batteries! Thanks for everybody's input. I went to local battery store (battery and bulbs) and spoke with the owner and my battery requirements. I decided against the AGM's because they were $290 each times 2.....no thank you. I went with 2 duracell 12V Lead Acids which were comparatively a bargain at $81 a pop; got 2. I'll build a box to stick them in and then vent the box somewhere along the floorboard near the driver seat. This should be a good start with my 100W Renogy panel. Thanks again!

 

[RogueRV2]

Nice. Thanks for sharing. That made it quick and easy to determine that I can only allow them to go without sun for 2 days before I might have to charge them with a generator to extend their possible life span to nearly 5 years. I'm glad to have that charge controller with the duo battery charging option, because one can add a second and new set of batteries that would reduce the DOD to 20% and really extend the battery life span of both sets...