I have a 100w 5.5amp solar panel with a 30 amp controller i was wondering what is a good size/amp hr battery and converter to get the most out of it?

Any comments would be appreciated.

SolarIsTheWay said:

Any comments would be appreciated.

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SolarIsTheWay said:

Any comments would be appreciated.

Click to expand...

I believe that if you watch Will Prowse's YouTube channel you'll very quickly figure out that 100Ah is possibly the most common capacity for lithium iron phosphate batteries. Whether buying a drop-in Renogy or Battle Born or assembling your own 4s battery pack (watch the videos; you'll see what's involved), 100Ah is likely as high a capacity battery you can use with your 100w panel. In full sun it would take your panel 5 hours to fully charge the battery.

SolarIsTheWay said:

Any comments would be appreciated.

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Well, it all depends on what you wanna run off it, and what duration.

what latitudeis your location? How much sun can you get? 100watts in Alaska/Canada isn’t NEARLY what it would be in Ecuador...

So, average, 50watts for 6 hours a day... it’ll be a 12v panel, so only puts out that near high noon... because the voltage is too low mornings and evenings, unless you are aiming the panel constantly... so, figure, 250Wh per sunny day...
so, not much input.

If the battery is only used once a week, you can figure 1KWh can be used, and then let it recharge all week...

if it is used daily... I wouldn’t plan on more than100Wh usage, so, the next day sun could rebuild it...

You need to work backwards from load, or how you want to use the power. So far the only thing I've done with my 100W is charge my cell phones. While I have it on AGMs, with the weather so crappy here in Dec, I haven't been motivated to really test how much I can get in a day. Plus, I need to cut a very big tree down to double my production. After that, I want to test how long it can keep my landscape lights lit when spring comes. I'll be using some used AGM batteries I got off craigslist for that. I think they are something like 37-39Ah, and I use 2 in parallel.

My biggest problem is I have non LEDs up to 20W on the string. I doubt it can keep them going for long. So, I may have to restring the LEDs to be on a separate line. So, at the end of the day, I'll find out how much gas I get from the Sun during the day, then see how many hours they can keep the lights on at night. You have some good estimates above on what you can hope for. I'll make a note to report back in months what I can accomplish with the 100W panel when the tree is gone and I have the landscape setup in place.

You must have a low voltage cut off in your system or you will kill those batteries.

If you want a lead battery i would go no bigger than a group 24. Or a 50A AGM. 5A input is little more than a trickle charge so you will struggle to fill lead up everyday if you do more than small cell charger/LED loads daily.

IF you get a lithium size doesnt matter.