paralleled charge controllers

[almac]

Run you generator and read this.

thanks for the edited update. got a hydrometer and batteries were about 1.150, about 25% ran the gen for a while got them to 1.250 will take them out of service and put them on the solar CC till i can get them to 100%

[Sunking]

thanks for the edited update. got a hydrometer and batteries were about 1.150, about 25% ran the gen for a while got them to 1.250 will take them out of service and put them on the solar CC till i can get them to 100%

Take my advice, use the generator and get them to 100% ASAP. That is going to tell you where you stand and minimize battery damage/stress.

Also be aware you might learn something you will not like one little bit if my hunch is right. Once you get to 100% via genny, you will notice there is no voltage high enough for you to get back to 100% on panels. Most likely will notice you loose ground each day and will be forced to run the generator often.

If that happens can only mean one thing. You do not have enough panel wattage. Or you use too much for the panel wattage you have. Whichever way you want to look at it, but end result is the same, chronic under charging and deficit charging requiring genny to catch up. Hopefully if you do notice that the problem goes away in warmer months with longer days.

Physics is not like man made laws or credit. If you spend $10 day and only make $5, you will die if you are a battery. No one will give you credit or feel sorry for you.

Good Luck

SK

[almac]

Take my advice, use the generator and get them to 100% ASAP. That is going to tell you where you stand and minimize battery damage/stress.

Also be aware you might learn something you will not like one little bit if my hunch is right. Once you get to 100% via genny, you will notice there is no voltage high enough for you to get back to 100% on panels. Most likely will notice you loose ground each day and will be forced to run the generator often.

If that happens can only mean one thing. You do not have enough panel wattage. Or you use too much for the panel wattage you have. Whichever way you want to look at it, but end result is the same, chronic under charging and deficit charging requiring genny to catch up. Hopefully if you do notice that the problem goes away in warmer months with longer days.

Physics is not like man made laws or credit. If you spend $10 day and only make $5, you will die if you are a battery. No one will give you credit or feel sorry for you.

Good Luck

SK

thanks. iv got 750w of panel for 2 x 100ah 12v batteries in series at 24v. so its a 24v 100ah battery bank?? i think the panel wattage is plenty. i have some sun today. the batteries are only 3 weeks old but iv been undercharging/over using them. the battery i think is already a bit sulfated. the charge is dribbling in to the batteries at about 2-3amps at 29.6v with the panels delivering 15amps at 36v to the CC the hydrometer is reading 1.200 still. now they have stopped accepting charge at 1.200. the CC has gone to float. so looks like i need to equalize them, they wont accept charge off the battery charger either. stuck at 1.200 now i will have to get a dc power supply that can be manually adjusted to 31v

[Living Large]

iv got 2 x 100ah 12v batteries in series at 24v. so its a 24v 100ah battery bank??

Yes, that is correct.

[Sunking]

thanks. iv got 750w of panel for 2 x 100ah 12v batteries in series at 24v. so its a 24v 100ah battery bank?? i think the panel wattage is plenty. i have some sun today.

I understand what you are saying. 750 watts on a 24 volt battery gives you roughly 28 amps of charge current. That is actually a bit more panel wattage than the batteries can handle at a C/4 charge rate. However that does not mean you have enough panel wattage, it just means your batteries are too small.

Use a money example. Lets say you open an account with $100 (100 AH). You require $75/day (75 AH) to live, add make $50/day. You are bankrupt with a $25/day deficit.

A healthy account would open with $375 (375 AH). You still require $75/day (75 AH) to live, but you make $80/day (90AH). You would be running a surplus plus enough cash for you to miss a couple of days work when it rains.

Does your controller have an EQ setting and how how high can you set it? EQ voltage is 30 to 32 volts. When you see the current taper off, measure battery voltage. If you have it set for 30 volts, and the current tapers off, you should see 30 volts on the battery. It can take up to 12 to 24 hours to EQ.

[paulcheung]

thanks. iv got 750w of panel for 2 x 100ah 12v batteries in series at 24v. so its a 24v 100ah battery bank?? i think the panel wattage is plenty. i have some sun today. the batteries are only 3 weeks old but iv been undercharging/over using them. the battery i think is already a bit sulfated. the charge is dribbling in to the batteries at about 2-3amps at 29.6v with the panels delivering 15amps at 36v to the CC the hydrometer is reading 1.200 still. now they have stopped accepting charge at 1.200. the CC has gone to float. so looks like i need to equalize them, they wont accept charge off the battery charger either. stuck at 1.200 now i will have to get a dc power supply that can be manually adjusted to 31v

Maybe you should set the absorb voltage to 32 volts and make sure watch the temperature of the battery, don't made them reach to 50 degree C or 125 degree F.

[almac]

Maybe you should set the absorb voltage to 32 volts and make sure watch the temperature of the battery, don't made them reach to 50 degree C or 125 degree F.

thanks for all the replies, my CC was useless for correcting this. its max voltage setting is 29.6v bulk. 28.4v float. only has bulk and float. i had to buy a dc power supply with adjustable voltage. its a 25amp 0-16v variable. set it up and its doing the trick. put the batteries in parallel and set the voltage to 15.4v and its taking 10-15amps. gassing . here are 2 picsDSCN7638.JPGDSCN7639.JPG

i have to check the settings every 15mins. am using a multimeter to check, not relying on the analogue meter on the power supply, the sg is improving slowly

[Sunking]

thanks for all the replies, my CC was useless for correcting this. its max voltage setting is 29.6v bulk. 28.4v float. only has bulk and float.

This is telling you there is no voltage high enough you could set your controller. It means you do not have enough panel wattage.

In addition your battery bank is too small for your under powered solar panels. Your system is completely out of balance, both your panel wattage and batteries are too small. Your batteries are receiving a C/4 Charge Current. They should be no higher than C/8 which means to match your panel wattage need twice the Amp hour capacity. It also indicates you are way over discharging your batteries every day because with a a panel wattage that exceeds the batteries maximum charge requirment cannot even get them recharged in a day.

If I had to guess right now your battery needs to be at least a minimum of 4 times larger in capacity , and 2 times higher panel wattage. Possible even more.


Sorry but after putting all the pieces of information you have given over many threads, there is no other conclusion. It looks like a duck, quacks likes a duck, swims like a duck, and flies like a duck. Its a Duck.

[aleeu]

Perhaps your terms are incorrect. You cannot Parallel Charge Controllers. You can use two controllers on a common battery, but they are not in parallel. They serve a common battery

Example lets say you have two 40 amp controllers, a 24 volt battery, and a total of 4000 watts of solar panels. You would have two solar panel arrays of 2000 watts each, and a single controller on each panel array. Both Controllers then supply a common battery.

What you will see is one Controller will be dominant. It will be the first to turn on, and last to turn off. Just set the voltage on the dominant controller slightly less than th eother until you can get them to equal as best as you can. It will never be perfect so don't knock yourself out trying for perfection.

The CCs are paralleled to the battery bank, each CC with its own arrays. What I don't get from them is for controllers A and B to power my loads, only one do the job the other's output remains zero. I thought they should all supply amps to the inverter for the loads.

[Sunking]

The CCs are paralleled to the battery bank, each CC with its own arrays. What I don't get from them is for controllers A and B to power my loads, only one do the job the other's output remains zero. I thought they should all supply amps to the inverter for the loads.

That is not going to happen because the batteries internal resistance is to low and your electronics are not that accurate. The controllers internal electronics accuracy tolerance would have to be within .001 volts or roughly 0.1% or better precision. No electronic equipment is that accurate in your price range. Not a lot of lab and test equipment is that accurate. Generally speaking only Calibration, Scientific, Aviation, Wights/Measure, Navigation, and high end Test Equipment gives you that kind of accuracy. Not consumer electronics. It is not needed or required for charging batteries.

Now if you buy a CC with a Load Sharing (able to talk to each other) will get close, but still not going to be equal. If you do not have such a controller and really are a bored worrywart, you can adjust the voltage of the two controllers to get as close as they physically can. Either lower the voltage of the hottest controller incrementally by .01 volts, or raise the lowest incrementally by .01 volts until you get close. If your controller does not have .01 volt resolution, you are SOL and have to work with what you have. FWIW .01 volts is roughly 1% tolerance. To get what you want takes .1% or better. Just not going to happen.

Don't worry about it, as long as they both produce full power in the mornings when the batteries are discharged demanding full power is all you need. Just like parallel batteries, the stronger controller is going to do most of the work when things are not equal.

[almac]

This is telling you there is no voltage high enough you could set your controller. It means you do not have enough panel wattage.

In addition your battery bank is too small for your under powered solar panels. Your system is completely out of balance, both your panel wattage and batteries are too small. Your batteries are receiving a C/4 Charge Current. They should be no higher than C/8 which means to match your panel wattage need twice the Amp hour capacity. It also indicates you are way over discharging your batteries every day because with a a panel wattage that exceeds the batteries maximum charge requirment cannot even get them recharged in a day.

If I had to guess right now your battery needs to be at least a minimum of 4 times larger in capacity , and 2 times higher panel wattage. Possible even more.


Sorry but after putting all the pieces of information you have given over many threads, there is no other conclusion. It looks like a duck, quacks likes a duck, swims like a duck, and flies like a duck. Its a Duck.

it might look like a duck to you but you need glasses because you cant see. the CC is the problem. it only allows max bulk voltage of 29.6v. this is built into the cc, its in the spec sheet.. the panel wattage is plenty at 750w. in winter im getting 20amps at 36v = 720w. i dont want any more than this so its probably too big. my CC is rated for 720w max so when summer comes i will have to lose a panel. but yes thanks for pointing out i could double my 24v battery bank to 200ah. this would reduce my discharge rate. the reason my batteries are over discharged at moment is mainly because im a newby and on a learning curve. it will never happen again. also been cloudy for 2 weeks doesnt help

[paulcheung]

it might look like a duck to you but you need glasses because you cant see. the CC is the problem. it only allows max bulk voltage of 29.6v. this is built into the cc, its in the spec sheet.. the panel wattage is plenty at 750w. in winter im getting 20amps at 36v = 720w. i dont want any more than this so its probably too big. my CC is rated for 720w max so when summer comes i will have to lose a panel. but yes thanks for pointing out i could double my 24v battery bank to 200ah. this would reduce my discharge rate. the reason my batteries are over discharged at moment is mainly because im a newby and on a learning curve. it will never happen again. also been cloudy for 2 weeks doesnt help

That is why you need to spend some good money buy a quality charge controller. they asking high price for a good reason, get the job done right!!

[Sunking]

it might look like a duck to you but you need glasses because you cant see. the CC is the problem. it only allows max bulk voltage of 29.6v.

Then you do not understand batteries and energy. 29.6 volts is an EQ voltage for a 24 volt FLA battery. It is plain as the nose on your face. If your batteries cannot fully recharge at 28 volts you do not have panel wattage.

A 24 volt battery should fully recharge at 27 volts within 24 hours if they charger has sufficient capacity.

You may not like what I am saying, that is OK. It is not my problem or money. I am just trying to help you. Not my fault you do not like the answer.

EDIT if you cannot get a battery charged in 1 day with a C/4 charge current is a clue. It's a DUCK.

[almac]

Then you do not understand batteries and energy. 29.6 volts is an EQ voltage for a 24 volt FLA battery. It is plain as the nose on your face. If your batteries cannot fully recharge at 28 volts you do not have panel wattage.

A 24 volt battery should fully recharge at 27 volts within 24 hours if they charger has sufficient capacity.

You may not like what I am saying, that is OK. It is not my problem or money. I am just trying to help you. Not my fault you do not like the answer.

EDIT if you cannot get a battery charged in 1 day with a C/4 charge current is a clue. It's a DUCK.

ok the reason for the lack of panel wattage is because its been cloudy every day for 2 weeks. let me clarify... when the sky is clear and the sun is shining... i get 18amps at 36v . more than enough. but when its cloudy like it has been here every &#@* day i get next to zero!! this has shown me the limitations of solar. you cant rely on the %&#@ sun!!

[paulcheung]

ok the reason for the lack of panel wattage is because its been cloudy every day for 2 weeks. let me clarify... when the sky is clear and the sun is shining... i get 18amps at 36v . more than enough. but when its cloudy like it has been here every &#@* day i get next to zero!! this has shown me the limitations of solar. you cant rely on the %&#@ sun!!

That is when the generator comes in to rescue.