jrh613
Solar Newcomer
Posts: 9
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Post by jrh613 on Sept 14, 2018 3:27:39 GMT
I need to learn to type. :-) Not 400AH. It has a reserve capacity of 450. That means that at 25A and nominal temperature, it can produce current for 450 minutes. My understanding is that it is a good idea not to exceed about half of that. So, yes, 220AH is probably a good guess. Maybe a little less. I am a bit confused by tattoo's claim that there are better batteries. There are some that have longer life. But, $ per AH... I picked the 8 D up for $232, including tax. So, its cost is about $1 per AH. Not sure that is confined that it can be overpower like the tracer (commander), ie it is not clear from the manual. A single 8 D is 400ah? more like 220ah. Ok. This answers my question. Thanks! One followup, though... Grumpy gave numbers for the Commander. But, is the Rover similar? I have the 40A Rover.
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Post by tattoo on Sept 14, 2018 3:36:18 GMT
I am a bit confused by tattoo's claim that there are better batteries. There are some that have longer life. But, $ per AH... I picked the 8 D up for $232, including tax. So, its cost is about $1 per AH. However, the reserve capacity is the important number for solar. I do not think you will find a larger battery than this. Sure they make much larger and much better batteries for solar.... What you have is an automotive Battery...
Just because you spent a lot of money on that car battery doesn't make it the best battery for solar...
Like I said you seem to have it all figured out...
Good luck
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jrh613
Solar Newcomer
Posts: 9
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Post by jrh613 on Sept 14, 2018 11:56:33 GMT
Maybe you would like to share, then... I am a bit confused by tattoo's claim that there are better batteries. There are some that have longer life. But, $ per AH... I picked the 8 D up for $232, including tax. So, its cost is about $1 per AH. However, the reserve capacity is the important number for solar. I do not think you will find a larger battery than this. Sure they make much larger and much better batteries for solar.... What you have is an automotive Battery...
Just because you spent a lot of money on that car battery doesn't make it the best battery for solar...
Like I said you seem to have it all figured out...
Good luck
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Post by tattoo on Sept 14, 2018 12:13:31 GMT
Maybe you would like to share, then... No need you seem to know everything about solar already,
Have a good one...
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Post by bupkis on Sept 14, 2018 12:23:09 GMT
jrh613, your run of the mill golf car battery from sams/costco. Thick plates, designed for cycle life, They won't be able to deliver the current you starting battery will. I believe interstate now carries Trojan 6v golf car batteries, a good choice for cycle service. Shop batteries that have an ah rating, consult your local interstae store.
Keep you discharges low, charge FULLY regularly and you'll get good life out of your battery, if there is sun when you use the inverter the battery may not see any discharge!!!
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Post by tattoo on Sept 14, 2018 12:24:43 GMT
With eight100W panels, why would running a 500W AC for an hour or so each week exceed the capabilities of the system? The battery will certainly handle that much load; I already tested it for 90 minutes without solar panels/controller. And eight 100 watt panels should replenish the battery in an hour or so. (?) Or am I missing something? Jim See the above proves you have Solar figured out and what it can do.....
With everything in your shed running and the AC for an hour or two with one large car battery and you can charge it in 90 min or so.... I say yes your missing something......
Good luck....
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jrh613
Solar Newcomer
Posts: 9
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Post by jrh613 on Sept 14, 2018 12:41:47 GMT
Thank you, bupkis. I appreciate the golf car battery suggestion and will look into them. I would like to add more capacity in the future and want to pick the best option. jrh613, your run of the mill golf car battery from sams/costco. Thick plates, designed for cycle life, They won't be able to deliver the current you starting battery will. I believe interstate now carries Trojan 6v golf car batteries, a good choice for cycle service. Shop batteries that have an ah rating, consult your local interstae store. Keep you discharges low, charge FULLY regularly and you'll get good life out of your battery, if there is sun when you use the inverter the battery may not see any discharge!!!
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jrh613
Solar Newcomer
Posts: 9
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Post by jrh613 on Sept 14, 2018 12:45:00 GMT
Wow. Ok. So, if you are not able to help, that's fine. Several other posters have been able to make positive contributions about controllers, battery types, etc., that could help me and the original poster. Your comments remind me of the good old days of Usenet groups. With eight100W panels, why would running a 500W AC for an hour or so each week exceed the capabilities of the system? The battery will certainly handle that much load; I already tested it for 90 minutes without solar panels/controller. And eight 100 watt panels should replenish the battery in an hour or so. (?) Or am I missing something? Jim See the above proves you have Solar figured out and what it can do.....
With everything in your shed running and the AC for an hour or two with one large car battery and you can charge it in 90 min or so.... I say yes your missing something......
Good luck....
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Post by tattoo on Sept 14, 2018 13:12:45 GMT
Wow. Ok. So, if you are not able to help, that's fine. Several other posters have been able to make positive contributions about controllers, battery types, etc., that could help me and the original poster. Your comments remind me of the good old days of Usenet groups. See in the beginning I was trying to help you and understand your problem... But when you started asking questions that you already knew the answer to because you had already figured it out I didn't see any reason to try and help you.... Remember you have the biggest and the best.....
But at least me not helping has got you to start listing to people...
Yea I remember the good old days and like back then, I'm not here to hold your hand..... Were here to help...
Good luck....
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Post by bupkis on Sept 14, 2018 15:16:22 GMT
jrh613, lots of pros and cons and compromises, as I suggested if you use 500w while making 600w there is an excess to charge the battery or be wasted!
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Post by Admin on Sept 14, 2018 19:37:13 GMT
Ok. This answers my question. Thanks! One followup, though... Grumpy gave numbers for the Commander. But, is the Rover similar? I have the 40A Rover. 4 100w panels in series is ~5A x ~60-75v, parallel another 4 in series and ya get ~10A x ~60-70v. Do not confuse input limits with battery charge limits. An mppt controller takes that ~10A x ~70v and converts it to battery voltage for charging with amps ~45A or so (depending on batt voltage). Some mppt controllers can be overpowered and the controller clips excess current, ie a 40A controller with 1000w and the controller clips the battery charging current to 40A and the rest is wasted anytime excess is made. As grumpy showed, that controller can be overpower to 1500w @ 12v. Only the Commander has the ratings for accepting higher PV power at the specifications mentioned. The Rover does not. This diagram is from Page 11 on the Commander manual. -Renogy Team Attachments:
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Post by Admin on Sept 14, 2018 21:15:29 GMT
Admin, Are you saying that, for the Rover, I would be limited to four 100 watt panels (400W) since 12V at 40A is 480W? In that case, why are you selling an 800W kit with a 40A Rover controller on Amazon? www.amazon.com/dp/B07CTHH3RK/ref=psdc_2236628011_t2_B0747NXTZROnly the Commander has the ratings for accepting higher PV power at the specifications mentioned. The Rover does not. This diagram is from Page 11 on the Commander manual. -Renogy Team The maximum input ratings for the Rover 40 is 520W at 12V. www.renogy.com/template/files/Specifications/Rover%20203040.pdfListed on page 23 of the manual. In regards to the listing, it is 24V for 600W/800W. -Renogy Team
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Post by playersz28 on Sept 14, 2018 22:12:18 GMT
So if you run a 500w continuous load for the A/C that's about 42A out of the battery in an hr, add in for conversion losses and call it 45A. A 225AH battery will be good for 2.5hrs with no other loads and no charge input. If you have 600w of panels running maybe 85% efficient in full sun then you should be able to almost keep up with the A/C. With it running any other loads will deplete the battery. Maybe my numbers are all wrong though or maybe this is what you figured already.
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Post by tattoo on Sept 14, 2018 22:54:06 GMT
So if you run a 500w continuous load for the A/C that's about 42A out of the battery in an hr, add in for conversion losses and call it 45A. A 225AH battery will be good for 2.5hrs with no other loads and no charge input. If you have 600w of panels running maybe 85% efficient in full sun then you should be able to almost keep up with the A/C. With it running any other loads will deplete the battery. Maybe my numbers are all wrong though or maybe this is what you figured already. I believe your numbers are very close to correct in full sun like you said..... But he has the same problem I have..... Shade from trees and that's a HUGE problem.....
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Post by bupkis on Sept 14, 2018 23:27:57 GMT
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