Charging Batteries With Generator

[deekster59]

Thanks for the input Mike.

[Mike90250]

I want a 24 volt system with a large bank of AGM batteries.

Why AGM ? They have shorter life, higher cost, and unforgiving of mistakes. At least try a starter system of
cheap flooded batteries and when you get them to last 3 years, buy the pricey AGM's, maybe in 3 years, LFP
may be a reasonable option.

I need the room to improve the system later so am looking for a high end 8KW+ inverter.

This is now a 48V system. Over a 3Kw inverter is 48V territory.

I want to promote 5KW total.

huh ? you have a 8kw inverter. What does

promote 5kw

mean to you? 5kw continuous load ?

Charge controller with hybrid function for solar and wind turbine

Generally a bad idea, really bad for large system. choose the best of each mfg for each function.
with 8KW, you need several 60A 48v charge controllers

want to hook my 6000 watt 25 amp/120 volt generator to the system. I would certainly appreciate the input.

Then you will need to investigate how to get a 240V generator or how to get 240V out of your generator.
120V is not viable for more than 1200 watts of charger, they are just not made.

[deekster59]

Not sure how this is relevant to the questions asked within, but everything you are talking about is. My question now, is I want an off grid system in my home and have researched enormously the variables and am more confused now then when I started. I built a system off grid for a friend many years ago and it worked fine but with the advancing of technology and costs dropping I'm more inclined to go all out here. I want a 24 volt system with a large bank of AGM batteries. I need the room to improve the system later so am looking for a high end 8KW+ inverter. I want to promote 5KW total. Charge controller with hybrid function for solar and wind turbine and I want to hook my 6000 watt 25 amp/120 volt generator to the system. I would certainly appreciate the input.

Thanking you in advance guys

[Svencool]

He has them in Series and I asked if I could check it out some weekend. So I will have more probably correct info to share and he is 100% off grid....

[inetdog]

Thanks Sunking! I was talking with a guy today that is totally off grid and hope to see his setup and learn a few things as well. I've learned allot from you guys and am much appreciated for it. But sometimes for me seeing is believing. He's running I believe 64 6v batteries in 4 strings at 24v. Thank You... Mike

The numbers you gave just do not add up.
64 6V batteries would be 16 strings of 4 batteries each producing 24V nominal.
If it is really 4 strings of 4 that is only 16 batteries.
And 4 strings in parallel is way too many.
One string is good, two strings well monitored may work for awhile.
You have the right idea about going to a higher voltage using 2V batteries at some point in the future.

[Mike90250]

64 6v batteries in 4 strings at 24v

Run away, Run away. Before it blows up. Just because it's not on fire, does not mean it's a "good installation", it means you should have bought a lottery ticket that day.

[Sunking]

Thanks Sunking! I was talking with a guy today that is totally off grid and hope to see his setup and learn a few things as well. I've learned allot from you guys and am much appreciated for it. But sometimes for me seeing is believing. He's running I believe 64 6v batteries in 4 strings at 24v. Thank You... Mike

That is not someone you want to use a mentor or an example. Well that would be a great example of what not to do.

[Svencool]

Thanks Sunking! I was talking with a guy today that is totally off grid and hope to see his setup and learn a few things as well. I've learned allot from you guys and am much appreciated for it. But sometimes for me seeing is believing. He's running I believe 64 6v batteries in 4 strings at 24v. Thank You... Mike

[Sunking]

As for your genny question. Today you would need a 2 Kw unit and a 12 volt 60 amp charger That will give you 750 watts of charging power which is about the max your batteries can take.

Smart money says wait until you get your equipment matched up because right now you have a bit of a mess that is way beyond any 12 volt limits. You have to much panel wattage and not enough batteries operating at the wrong voltage.

Example the equipment limits on 12 volts is about 1000 watts, on a 800 AH battery. You have more panel wattage than that and only half the battery capacity. So wait until you know where you are going.

24 volts is good to 2000 watts @ 800 AH battery
48 volts is good to 4000 watts @ 800 AH battery.

You are already into 24 volt battery territory with your panel wattage.

[Svencool]

Ok I can trip a breaker and take one of them out of the mix!

[Sunking]

Sorry I meant to say 5 panels not 6 sorry! Batteries are wired Parallel. After these batteries get spent. I plan on using 2volt batteries and wiring them in series at a higher voltage 48v These are serving there purpose for now....

Ok you have 1500 watts of panels with a 96 amp charge controller into a 12 volt 400 AH battery.

At 1500 watts of panels into a 12 volt battery requires 125 amp charge controller. You have 5 panels a prime number which means you can only configure them all in parallel loosing a lot of the benefits of a expensive charge controller. At 96 amps of charge current into 400 AH battery is a C/4 charge current which is to much.

You would be ahead of the game if you lost 1 panel, and reconfigured your panels in 2S2P. Still leaves you at the same C/4 charge rate.

You have to much panel wattage, and not enough batteries. Never use a prime number of panels except 1 and 3. With 3 and many conntrollers you can wire them is series doing away with fuses and combiners and a lot less hardware saving some serious money.

With 5 panels you need a combiner with 6 ports and 6 breakers. With 4 panels 2S2P no combiners or fuses are needed. Maximum input on your controller is 1200 watts with a 12 volt battery. So with 5 panels you are 300 watts over the limit.

[Svencool]

Sorry I meant to say 5 panels not 6 sorry! Batteries are wired Parallel. After these batteries get spent. I plan on using 2volt batteries and wiring them in series at a higher voltage 48v These are serving there purpose for now....

[Sunking]

Well SunEagle he has another huge problem on his hand. Makes no difference really how those 4-12 volt 100 AH batteries are configured with 1800 watts of panels. Do the math and you will discover his charge rate is greater than C/3. So all I can say he had better be configured for 24 or 48 volts with AGM batteries.

[SunEagle]

I have a small setup with 6 300w panels running into a Midnite Classic 150 with 4 12 batteries 100ah each for a total of 400ah. During the winter months is it possible to charge them with my external generator? I have a 10,000 watt Generator and am not sure how I would do it.... Thanks for any help....

You would use a battery charger that is set up for the voltage and chemistry of your battery system. It would be powered from your generator.

Now as Sunking asked are your 4 12v 100Ah batteries wired in series or in parallel? Because with 1800 watts of panels you have certainly exceeded a 12volt battery system and you can't create a 24volt or 48volt 400Ah system with 4 x100Ah batteries.

So help us help you by telling us more about how you have your system wired.

[Sunking]

Well I hope you have the batteries wired in series for 48 volt @ 100 AH. It should be anyway with 1800 watts of panels. Anyway assuming it is 48 volts will require a 48 volt 15 amp charger. Just buy you a 48 volt golf cart charger rated 15 to 25 amps.

The only way you can have 400 AH if you wired the batteries in parallel for 12 volts which is a huge No-No, and just plain silly because with 1800 watts of panels would require a second Midnite 150 Classic Controller. If that is the case it would need a 12-volt 50 to 60 amp charger and will cost a fortune. If you running 12 volts you need to throw away 2 panels in the trash and be prepared to replace the batteries every year.

Ideally you would want a 1500 to 2000 watt, 48 volt Inverter, with Built-In 20 Amp charger and generator support.