Another solar/battery/ 12 volt question.

[Weight]

Ryobi also has a large variety of devices that are Ryobi-One 18 volt. They are good enough quality, and at a reasonable price point.

 

[musicman]

You also need to allow for 50 % use of your batteries. Additionally solar panels are not 100% efficient therefore a 100 watt panel yields about 80  watts, rule of thumb is 20 % loss
Anything that is used for heating or cooling is the power hogs. There are 12 volt coffee makers,  crock pots, etc available. I got mine at a pilot truck stop.

I'm still a believer in looking on your appliance or equipment and see what the power rating is. That rating is per hour. A 200 amps/hr  battery is 2400 watts / hour 50 % is 1200 watts/hour.
A 200 watt solar panel is going to need about 7 hours to recharge your battery to full power if its at the 50% level.200-20%=160watts/hour.
1200/160=7.5 hours.
Bill

 

[Sleep]

Weight - I had planned on going with Ryboi so this charger would be good to have.

Musicman - Thank you for the written out specs.  I am one of those people who learn from pictures or by doing, so sometimes all the different post tend to melt together. 

I have 3 pages of notes on solar and the batteries, but it's still not quite right, but closer!   (Can I have a badge yet?)

 

[John61CT]

> A 200 amps/hr  battery

200 AH or amp-hour or "amp hour", is not amps per hour, not a rate of usage over time, but a static total quantity

> 2400 watts / hour 50 % is 1200 watts/hour

Same, watt-hours or Wh

Depending on latitude, season, temp, weather etc you're lucky to average 60-80 AH per day from 200w of panels. Desert conditions more of course, but up north in winter 400+ watts is more like it per 200AH of bank.

 

[Weight]

I find my solar panel doesn't have to match the battery AH. It has to match or exceed the AH amount used from the bank. My 400 watts keep my 690 AH bank charged using lights, fan, fridge, and coffee pot once a day, microwave less than 10 minutes a day. A large bank helps with Peukert.

 

[John61CT]

Absolutely right.

The calculation I was commenting on assumed a 50% draw needing replenishment.

Shallower draws help the bank to last a lot longer, and you want the ability to go 2-3 days of poor weather,

but there comes a point where weight and space become an issue.

 

[musicman]

Exactly,  it's two ways to do solar, the calculating  method and the trial and error method.

 

[musicman]

That 50 % rule is for the battery life. If you keep your batteries at 50% or higher they will last a long time. Lifeline says theirs will last 10 years.
Like weight said you if you keep enough battery bank to fill your needs then you will always have enough There was one on a video had around 1000 watts of solar with 4 200 amp/hr batteries  but his usuage required it. Everything was electric, induction cook top and the works even a washer and dryer.

 

[John61CT]

If you have the ability to charge from a short genny run on demand then you can carry a much smaller bank. LFP makes a huge difference there as well.

 

[Sleep]

you match the panel output to the ah of the batteries.  so two 6v give you about 200+ah,  so you would want at least 200w of panels.  note,  this is considered a minimum,  this is one case where more is better.  highdesertranger

So I'm on the Batteries Plus , website looking at batteries, but as usual am confused. If I am looking at 200+ah for my 2-100 watt panels and I am looking for AGM Deep Cycle the AH seems low even on the Duracell

https://www.batteriesplus.com/productdetails/sli27magmdc - this one has only 92 ah so I would need 3?



This is not an AGM, correct? But it does have the 215 AH but is only 6 volt, so I would still need 2 and venting?

https://www.batteriesplus.com/productdetails/sligc110 - 

Is this right?

 

[highdesertranger]

the first one(12v) is not a true deep cycle. the second one(6V) is a deep cycle.

your kinda working backwards. this is how it should be done,

1. determine your daily power needs.
2. size your battery bank according to those needs.
3. size your solar to your battery bank.

now it really doesn't hurt to have more solar then you need. in fact during the winter it is actually better. the one watt of panel to one amp hour of battery is a minimum starting point. so lets get on to what battery(s) you need. what do you think your daily usage will be? highdesertranger

 

[John61CT]

Yes you want a pair of flooded Duracell, their AGM sucks.

May be a bit cheaper at Sam's Club.

No need to vent unless you enclose, or the smell bothers you.

 

[John61CT]

You can always add more panels later

Just make sure you only use a bit less than what you put in each day.

Or make sure you replace what you use every day plus a bit.

 

[Sleep]

the first one(12v) is not a true deep cycle.  the second one(6V) is a deep cycle.

your kinda working backwards.  this is how it should be done,

1.  determine your daily power needs.
2.  size your battery bank according to those needs.
3.  size your solar to your battery bank.

so lets get on to what battery(s) you need.  what do you think your daily usage will be?  highdesertranger

Ok this might be off a little, Fantastic Fan, smaller 12 volt fan (2.5 watts per hour x 4 =10 watts)
12 volt dometic or the equivelent (4.5 w. x 24 = 108 w.), lights (2.5 w x 6 = 15 W), phone and tablet (every other day),  12 volt tv w/DVD ( .8 amps = 28.6 watts x 2-4 hrs per week.)

I hope this is right, feel free to correct me.

 

[John61CT]

Just for consistent nomenclature:

Ok this might be off a little, Fantastic Fan, smaller 12 volt fan (2.5 watts per hour x 4 =10 watts)
12 volt dometic or the equivelent (4.5 w. x 24 = 108 w.), lights (2.5 w x 6 = 15 W), phone and tablet (every other day),  12 volt tv w/DVD ( .8 amps = 28.6 watts x 2-4 hrs per week.)

I hope this is right, feel free to correct me.

Watts and amps are instantaneous "flow rates".

Quantity stored or used over time is watt-hours wH or amp hours AH. Not watts per hour, that has no meaning.

So if your fan averages 2.5 watts, you run it 8 hours a day, that's 20 watt-hours per day.

If you use a total of say 700wH per day, at 12V that's about 60AH. Unless you're running a little genny, say you have solar only, in good conditions 300-400w will be enough.

But you want a bank gives you a 3-day buffer, if lead only 50% is usable, so 60AH * 3 = 180AH , * 2 = 360AH

So two pairs of FLA Duracell GCs is more than enough, if it's always sunny one pair's enough.

Above just an example of course, others use different rules of thumb.

 

[highdesertranger]

x2 two 6v volts sounds like a good match. for both your usage and your panels. highdesertranger

 

[Sleep]

x2 two 6v volts sounds like a good match.  for both your usage and your panels.  highdesertranger

Thank you again Highdesertranger, I think I've got it!  :-/ Lol

 

[DLTooley]

The domestic should be 4.5 amps, not watts which would be 54. It is also not a continuous draw and will be weather dependent.

 

[wayne49]

Speaking of Trojan T105. Trojan has a T-105RE version for $20 more, "designed" for renewable energy systems.

Same AH.

http://www.batteriesinaflash.com/au...h-t105-re-renewable-energy-deep-cycle-battery

Regular T105

http://www.batteriesinaflash.com/au...6v-225ah-deep-cycle-flooded-lead-acid-battery

I am wondering if someone can wade in and figure out what the $20 is buying and how would it impact a solar setup vs T105 plain.

Thanks,
Wayne

 

[Weight]

Visited my friend at his Battery Plus Bulb. Most Duracell batteries do not have East Penn listed as manufacturer for this year's batches. Only the EGC2 have East Penn listed on the case as manufacturer. They all, plus some other labels, have listed a distributor, but do say made in the USA. My guess is closest factory, which E of A would be Penn.