Author Message
kevin stewart
Post     Subject: Using a generator to charge a battery bank.

Yes, stick to a 12 volt system, lights,stereo whatever. Then use an inverter for your ac devices.

I use car batteries because i can get them cheap and i'm broke. The thing is to never deplete them.

I think a 5kw generator for $150 is buying someone elses problem. It's too cheap.
Consider even a 3amp solar panel, it will do the job QUIETLY.

i have seen a hand crank diesel attached to an alternator, high amps, it worked great.

I have always wondered about a lawn mower engine attached to an alternator.
If i had an electric car there would be a solar panel on the roof and that mower engine charger in the trunk.( the exhaust leading out of or into the car depending on my mood.)
Steven Harris
Post     Subject: Using a generator to charge a battery bank.

Sean... unless you are going to run a full renewable system that hooks into your electrical panel and powers the whole house, with a bunch of panels, and a large battery bank, I would NEVER get away from a 12 volt system. If you are running a full RE system, keep in mind that inverter / charger is $1200 to $2500+ bucks, then there will be a recommend battery voltage for each system depending on its size.

So unless you are doing that then don't ever get away from the 12 volt system, all you'll do is just be spending money you don't need to spend and not gaining anything but a headache.

If you are adding solar panels to a system, you can put your panels in SERIES and run up to about 150 volts of solar panels into an MPPT solar charge controller and it will convert down the voltage to perfectly charge a 12 volt battery bank and work with your 12 volt inverter. This is pretty cool because the panels are usually some distance away and now with 150 volts or less in panels you can run a dramatically smaller wire from the panels back to the MPPT charge controller. That will save you a lot of money in copper.

Sean Henry
Post     Subject: Using a generator to charge a battery bank.

When would you recommend going to a higher voltage system? I have not decided if I will run a whole house from batteries in the future but I find it likely that I might, depending on what will be viable to generate electricity on the property.

I should have been clear on the lighting, I will not actually be using incandescent bulbs but CFLs or LEDs (LEDs are still ~$9 each in my area). I was sizing the system with a worst case scenario in mind so 300w for 6 hrs realistically that would be 110w that I would be using and still have room to charge my laptop 65w. So by building it for 300w for 6 hrs but only using 100w for 6hr I would have 66% left.

As for batteries my end goal will be to get GC2 batteries. For now I was going to use flooded starter batteries since I can get them for about $16 and will get $10 back when I have them recycled. Other than the price the reason that I was look at going that way is the batteries will only be sheltered from rain and snow but essentially sitting in a wooden box field.

I typed the message then listened to the podcast.
Steven Harris
Post     Subject: Using a generator to charge a battery bank.

Sean, you'd be extremely foolish to go 24 volts, especially on your budget, 24 volt chargers and 24 volt inverters are VERY expensive, stick 12 volts ONLY. Also....go to and listen to my podcast with Jack about Selecting the Right battery for YOU.. its Battery Show #1, or get my video on the subject, Paul has it advertised at the top of these pages. You DO NOT want a 'car battery'. NOT even if they are free. They won't last even a dozen or so 100% discharges... and ... why on Gods Green Earth are you going to run multiple 75 watt light bulbs. 7 or 8 watt LED's are bright enough for what you want (40 to 60 watt eq LED bulbs) and I even call those TOO BRIGHT. I prefer people run 2, 3, 4 or 5 watt LED or CF bulbs inside the house.

These LED bulbs
1. are awesome
2. Are $3.97 at most home depots right now, for the 60 watt EQ bulbs. Funny, the 40 watt EQ bubls are $7.97.

Sean Henry
Post     Subject: Using a generator to charge a battery bank.

I just purchased some property there are no buildings or utilities on the property, I'm planning on purchasing a used generator on craigslist (~$150 for 5kw) and getting some used 12v car batteries. I currently have a battery charger I believe that it is <a href="">Schumacher 50/10/2 Amp Starter/Charger</a> I hope to use it to charge the batteries. (I will have a shed to house everything.)

My current plan is to have enough back up to run a stereo and 2-3 75w lights (300w total) for 4-6hrs. Then run the generator to charge the batteries or to use high power items.

I know it is not good to be running used batteries but this will just be till I need more power and start setting up a full battery bank to power the house that I will start building in ~2yrs.

Now my questions:
1. If I go with a 24v system is there any potential problem running two chargers. One to a parallel bank of 2 12v and the other to the second parallel bank that will be tied in series for 24v.
2. In general gas generators are they DC motors that convert to AC or AC motors that are conditioned to 120v?

I know I had a few more questions but I work phone keeps ringing.