why battery voltage drop much at bigining ?

[zolar]

mppt 3.pngmppt4.png thanks a lot J.P.M.
thanks a lot matrix , about my panel they are fitted in clean and clear place not even a cable shadow but as you said may be the orientation , and speaking about mppt I am going to buy one and thinking to start with ( makeskyblue 60 amp ) tell I increase my system I've read and seen some videos about it . I wonder if you can give me your openion about these 3 mppt charger plz.

mppt 1.png sorry I don't know how the pics comes that way , not in same line at end of the post

[Mike90250]

If you like buying a small MPPT charger. and buying up to a larger one, and then replacing it because it broke, just start buying stuff.

But if you calculate out what your power needs are, what size and voltage the battery bank will be , and how much solar PV you will use, then we can advise you on a charge controller.
Sadly, solar PV systems are un-forgiving, they are hard to scale up, and yesterdays parts won't play well with tomorrows gear.

4800 Wh requirement - is that for a 24 hour period, or is 3 days already calculated into that ? I can't guess as to what your inputs to the calculator were.

[Matrix]

Mike I believe he said that was for 8 hours. I went on the assumption that once the lights went off that was it for the day bc that's all the load he listed. But there could be more. And inverter idle use was also not factored, that could be another 600 to 2400 Watts per day .

[zolar]

thanks mike and nice hear from you again in this topic, and thanks a lot matrix for your reply,
but when I asked about the charger 60 amps before , its nothing to do with my old system.
I attend to build another system of 24v , already I bought 4 panels each 24v and 320watt and I bought another 2 batteries each 12v and 200amh I will connect them serial ( going to buy another 2 to increase the bank capacity connect them both serial then parallel with old 2 ).
now about inverter i attend to buy 3kw just for future load increase ( no brand in mind till now ) , at begining I bought hybrid ( mustsolar brand ) but after I read some negative comments about the hybrid system, so I returned it back , that's why now I am asking about charger , and about my using don't worry cuz I am just practicing and when i increase my system i will need only to buy more panels and batteries ( no need to change the charger and inverter unless i exceed the limit of amps ), but I think I will start with 300 watts daily 6hours

[Mike90250]

4, 320w panels can harvest 1200w , so for a 24V system, you need a charger rated for 40A.

If you have 400ah of batteries, you need at least 40A

With a 24V system, you should not plan on more than a 2kw inverter. If you want 3Kw, go for a 48V system. Your panels can be wired for it, you are planning on the batteries for it, and the charge controller drops to a 20A requirement,

[zolar]

Your panels can be wired for it, you are planning on the batteries for it, and the charge controller drops to a 20A requirement,

thanks mike but sorry I didn't understand this last part .
and why I can't go more than 2kw inverter ( if I increase panels and batteries )?

[SunEagle]

thanks mike but sorry I didn't understand this last part .
and why I can't go more than 2kw inverter ( if I increase panels and batteries )?

If you do the calculations you will find that a 2000 watt inverter at 24V can draw over 80 amps (2000w / 24V = 83.3A).

If you go with a bigger inverter you can easily exceed 100 amps which starts to get dangerous.

At 3000 watts & 24V you get 125 amps so going to 48v is safer for you and your system wiring.

[Justin B.]

I have the PowMR 60A MPPT controller with 24V battery bank and 900 watts of PV ( three parallel strings of 3 in series) and it has worked very well so far, about 8 months. The only problem is the cooling fan got a bit noisy but the seller sent me a new fan.

[zolar]

suneagle I have another topic but I can't go to it although I am logged in ( thanks ,,, and first few fast questions please )
I got message it says login as different user or send a message to admin , how I can send to admin plz?
when I click on the word admin it takes me to home page

[SunEagle]

suneagle I have another topic but I can't go to it although I am logged in ( thanks ,,, and first few fast questions please )
I got message it says login as different user or send a message to admin , how I can send to admin plz?
when I click on the word admin it takes me to home page

I am not sure why you have been blocked from that thread. There were a couple of posts that were "soft deleted" so they could not be viewed by the forum members. Maybe that is why you can't get in.

As for getting in touch with the Admin. Just make a post asking for Solar Pete to help get it straightened out.

You also should not include multiple links in a post. That triggers the anti spam software to make the post go to review.

[zolar]

thanks suneagle .. about multible links rule I know , and about making apost ( as I understand that I make new topic asking member called solar pete to solve the problem ) right?
and brother you said if I use bigger inverter with 12v system and I start a load that consume as an example 100amps its dangerous . sorry to say BUT WHY? since I will use bigger cable and I have enough battery bank and I use it for short time like an hour.
why if I need to exceed for example 80amps consumption I have to go higher voltage system? as I said if I use bigger cable size and got enough battery bank.

[SunEagle]

thanks suneagle .. about multible links rule I know , and about making apost ( as I understand that I make new topic asking member called solar pete to solve the problem ) right?
and brother you said if I use bigger inverter with 12v system and I start a load that consume as an example 100amps its dangerous . sorry to say BUT WHY? since I will use bigger cable and I have enough battery bank and I use it for short time like an hour.
why if I need to exceed for example 80amps consumption I have to go higher voltage system? as I said if I use bigger cable size and got enough battery bank.

IMO the 100 amp is a cut off point where the wire and fusing becomes critical for the system. If you have the electric smarts and follow safety rules for properly sized wire and it's over-current protection then you should be able to exceed that 100 amp "barrier".

While you may have the proper sized wires and fuse for high currents to your inverter you also have to understand that a high wattage rated inverter is both inefficient and can quickly drain the battery system if they are not sized for the high current draw. So while the 100 amp is a caution barrier it also keeps the inverter sized a little smaller which may protect your battery system from getting deleted quickly.

[littleharbor]

I am not sure why you have been blocked from that thread. There were a couple of posts that were "soft deleted" so they could not be viewed by the forum members. Maybe that is why you can't get in.

As for getting in touch with the Admin. Just make a post asking for Solar Pete to help get it straightened out.

You also should not include multiple links in a post. That triggers the anti spam software to make the post go to review.

I have the same inability to view a thread I was subscribed onto. I have noticed the OP (I think), has been banned.

I occasionally have, for no reason, apparently get restricted from viewing threads. Normally I just go around that by going to the list of todays postings and can get in that way. This posting, OTOH, seems to have been deleted.

[SunEagle]

I have the same inability to view a thread I was subscribed onto. I have noticed the OP (I think), has been banned.

I occasionally have, for no reason, apparently get restricted from viewing threads. Normally I just go around that by going to the list of todays postings and can get in that way. This posting, OTOH, seems to have been deleted.

It might have been deleted due to being a duplicate, contains spam or is now closed. Although you should be able to see a close thread. You just can't add a post to it.

[littleharbor]

It might have been deleted due to being a duplicate, contains spam or is now closed. Although you should be able to see a close thread. You just can't add a post to it.

Not sure if it was the OP who was banned but I noticed he was just banned.