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Posted: 10/11/2013 7:03:03 PM EST
Say you live in FL durning hurricane season and you want to make one or two battery/inverter packs that you can charge up and then bring in the house to run small loads when the generator is not running or just separate from the generator.

(the generator in question is a EU1000).

Is it better to buy a solar panel and a charger controller with it...
(http://www.solarblvd.com/Solar-Panels-&-Systems-12-Volt-Solar-Kits/c1_272/p2747/12-Volt-100-Watt-Solar-Panel-Kit-with-FREE-SHIPPING/product_info.html)

...or better to buy a 3 stage battery charger to just plug into the generator while it is running?

I will say that i have a little window AC unit to run on the generator. It would be on constantly to avoid load spikes. Could I run that and one of those 3 stage battery chargers?

I mean, it is better to get into the solar panel or just to buy the 3 stage charger and store more gas for the genny?

Either way, I would need a marine battery or two and a battery tender.

Can someone recommned a quality battery and high rate 3 stage charger?

I already have a couple small UPSs w/ 5 battery packs (4 9AH batteries in series) that I keep charged up, so that is already a self contained battery/inverter unit of couse, its just that I can't charge 48 volt strings w/ a 12v solar cell w/o using a 12 v battery and an inverter. That is just way too much inversion/conversion...
Link Posted: 10/11/2013 7:48:20 PM EST
In past threads it was mentioned that most solar setups are going to be very slow charging up your batteries.

If this is an ongoing thing and you want to charge the batteries and use them quickly the generator is needed.

I will let others mention chargers. I have a big old roll around old style jump start/battery charger schumacher item I bought back when I did more than a little bit of turning wrenches. This thing is old school but that generally means it works. I also have a cute little black and decker charger of some sort that is smart. It will tell me if I hook the cables up backwards and if it feels the battery is a lost cause it tells me that as well and won't even try to bring a dead vehicle battery back to life. As I recall the battery registered something like 6 volts and it is a normal 12 volt starting battery.

It died early and I need to warranty it, but I just sort of felt like the little black and decker should have tried anyway.

Black and decker charger was bought back when big lots had all the vector invertors and stuff.

I don't consider it high quality and plan to watch this thread to see what I can make myself spend on a decent smart charger.
Link Posted: 10/11/2013 7:50:10 PM EST
[Last Edit: 10/11/2013 8:24:57 PM EST by EXPY37]
What Biere says, use your genny to charge your batteries.


Here's an excellent way...

Just took this pix a few days ago, pls excuse the mess on the batteries, SO needs to get busy and clean them...

On the right is a Xantrex 40 Amp Truecharge.

They are 3 stage chargers and are 'smart' for various battery chemistries.

All you do is add a powercord to the 110 vac input and heavy cables and clips on the output.

The jumper cable you see is from Harbor Freight, good deal, a decent jumper cable set, all copper IIRC, ~$12 and you can cut in half to get two sets for two charger setups.

This charger came from ebay at a fairly good price.

Alternatvely you can buy the Vector VEC1093A 10/20/40amp smart charger for less than half or even less, on ebay... As low as $30 recently.

The reason I went to the Truecharge is because I can do an equalize cycle with it. This function isn't needed for what you want to do. But is desirable.






OH, the Truecharge isn't to charge this ^^^ bank. My SO was using it to top off a group 26 or whatever, deep discharge 12vdc battery.

The juice to do it WAS coming from the big battery bank.


All the support equipment for this bank is mounted above it. 3 Outback charge controllers for 3 solar panel banks, a Xantrex 1800 watt sine wave inverter and other stuff.

They run 2 chest freezers and other stuff all year long.

The 2 white wires going to the left are for the Kubota engine/alternator design project.


[Note the fusing technique to save some $$$ They are NON200 fuses from any hardware store or ebay if you want to buy them at a fair price]

They work real good...


Link Posted: 10/11/2013 8:07:50 PM EST
[Last Edit: 10/11/2013 8:17:42 PM EST by EXPY37]
For those mechanically inclined, you can mate an alternator to a small lawnmower engine, like a $75 engine from Harbor freight, or whatever you have lying around.

Here's my recent effort, but it doesn't have to be nearly as complicated, also, a lot of the knowledge curve has already been climbed -by me


Kubota/Alternator package


So, you can short circuit [no pun intended] the process.

OtherPower IIRC, makes brackets.

A little gas powered genny alternator package can charge your batteries FAST, compared to the chargers I mentioned above.



Link Posted: 10/11/2013 8:10:12 PM EST
[Last Edit: 10/11/2013 8:16:53 PM EST by EXPY37]
Finally, you can PARALLEL two or more of the 110vac to 12vdc chargers, if your budget can stand it.

This will cut the charge time approx in half.

You have to be careful not to create too high a charge rate for your battery bank.


Link Posted: 10/12/2013 2:19:33 AM EST
I asked a similar question after installing a transfer switch for a Honda 3500 genset... I'm single, retired, dine out most of the time, and really don't have a lot of valuable food stored...I would probably spend more in gasoline than is the value of the stored food.... I went through the 7 days in 2004 with a couple of 5 day coolers, and last summer worked out a method to work my ceiling fans...most of my hurricane supplies are converted to 12v or Sanyo AA Eneloops... I do have a Goal Zero 7w panel, but have decided on the 12v deep discharge trolling battery, with options to charge it off the car, or the generator... a 12v cigarette receptacle is attached directly to the negative terminal.... I don't have a need for an inverter, save for access to the internet, which may be a future addition....I did not include a battery box, as previous working with them on boats, never found one easy to carry...my AA controller charger works on 12v dc as well as 120v ac....

protective cap on the positive terminal removed for pic

Link Posted: 10/12/2013 3:48:02 AM EST
Lol, actually I kinda have both. I have a solar trickle charger to keep the 12v battery on my generator topped off so I can use the electric start, then a battery charger in the house. I installed a whole house generator style setup.
Link Posted: 10/12/2013 4:16:01 AM EST
[Last Edit: 10/12/2013 7:21:08 AM EST by rightwingnut]
I have these two small ups that use 48v battery packs. I guess I could leave one out side by the genny to charge packs and one inside to run loads and just swap the five pack out b/t them. That is a pretty good set up right now I guess.

The problem w/ solar is that I would not be able to charge the 48 v packs directly with them, so I'd have to buy trolling batteries as well to charge directly w/ the solar, and I'd have to get a 3 stage charger to charger and a trickle charger, wires, terminals etc... I guess if the sun is shining I will be running the little Air conditioning unit off the genny so I may as well put one ups outside with it tocharge battery packs and the other inside to run loads.

It would be good to get all that stuff, but what started out w/ a question whether to buy a HF solar panel kit on sale has spiraled into a big expensive project. I'll get all that stuff eventually I guess, but not right now.
Link Posted: 10/12/2013 6:45:22 AM EST

If the batteries you're wanting to charge are already inside of a UPS unit, I'd just plug the sucker into your genny, instead of trying to rig up an elaborate solar project.
Link Posted: 10/12/2013 9:59:12 AM EST
[Last Edit: 10/12/2013 10:00:29 AM EST by Cathan91]
You'll need a good battery charger if you have deep cycle batteries, even if you have a solar panel. Flooded lead-acid batteries need to be equalized on occasion. My battery doesn't need to be equalized since it's sealed, but my little panel doesn't always charge it----it can be cloudy for days/weeks on end here.

I started my little off-grid system with a generator, a 150 ah AGM deep cycle battery, an Iota 45 amp charger, and a cheap Cobra inverter. I've since added a 158W solar panel. Next step is to add a couple more panels and replace the 150 ah batt with several Trojan batts.

I like the Iota because it's a 3-stage charger and will automatically switch voltage based on the battery's charge and the type of battery. It runs just fine off my gennie (Honda 3500). It's also made in the US. My charger is a bit big at 45 amps for the 150 ah battery it charges, but I got it with the intention of getting a bigger battery bank eventually. Standard rule of thumb is the charger amperage should be a tenth of the battery bank's capacity, but I prefer ~25%. It's a balance between time it takes to charge and battery longevity.

My Iota says it'll draw a max of 750W, but it usually draws <100W (measured with Kill-A-Watt).




Link Posted: 10/12/2013 3:46:55 PM EST
Link Posted: 10/12/2013 5:14:56 PM EST

It's likely even worse than that TBS.

Bulk charging may be 80-some% efficient, but only gets your battery 80-90% "full". IMO squeezing that last part of the charge in w/ absorb is pretty damn inefficient, relative to the amount of time it takes.

To illustrate your point about clouds, angles, and other inefficiency, here's my last 45 days or so in terms of harvested sun-hours (kw harvested / array size):




The sun for sure is starting to get lower in the sky, but this ain't december/january...

Link Posted: 10/12/2013 6:12:26 PM EST
Link Posted: 10/12/2013 7:23:42 PM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By HomeSlice:

Bulk charging may be 80-some% efficient, but only gets your battery 80-90% "full". IMO squeezing that last part of the charge in w/ absorb is pretty damn inefficient, relative to the amount of time it takes.
View Quote


Yep.

Using a generator and battery charger for a couple hours can get you into the 70-80 percent charged ballpark - at which point it might make more sense to shut off the generator and use a modest solar system to complete the last 20-30 percent, over a much longer time period.

Example:
1. Run the generator from 7:00-9:00 AM to accomplish the bulk charge, before there's enough sunlight to produce any significant solar power.
2. Shut down the generator at 9:00 AM, and let the solar system finish off the battery charge over the next 5-6 hours of strong sunlight.
Link Posted: 10/12/2013 7:24:32 PM EST
[Last Edit: 10/12/2013 7:27:49 PM EST by EXPY37]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By The_Beer_Slayer:
yea that was figuring PEAK efficiency hours. you really only get that about 3-4hrs during the day
View Quote




That's why, I think, it makes a lot of sense to have multiple ways to charge a battery bank.

The sun can't be depended on to shine when it's needed, if there's fuel, a genny can be depended on to charge them, but at the cost of using up a precious commodity.

The Kubota/alternator I'm building is to get the batteries 'bulk' charged electrical demands are high, and the batteries won't be damaged because most of the time they are fully charged most days, at least the way we use them.

Link Posted: 10/12/2013 8:25:07 PM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Skibane:


Yep.

Using a generator and battery charger for a couple hours can get you into the 70-80 percent charged ballpark - at which point it might make more sense to shut off the generator and use a modest solar system to complete the last 20-30 percent, over a much longer time period.

Example:
1. Run the generator from 7:00-9:00 AM to accomplish the bulk charge, before there's enough sunlight to produce any significant solar power.
2. Shut down the generator at 9:00 AM, and let the solar system finish off the battery charge over the next 5-6 hours of strong sunlight.
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Skibane:
Originally Posted By HomeSlice:

Bulk charging may be 80-some% efficient, but only gets your battery 80-90% "full". IMO squeezing that last part of the charge in w/ absorb is pretty damn inefficient, relative to the amount of time it takes.


Yep.

Using a generator and battery charger for a couple hours can get you into the 70-80 percent charged ballpark - at which point it might make more sense to shut off the generator and use a modest solar system to complete the last 20-30 percent, over a much longer time period.

Example:
1. Run the generator from 7:00-9:00 AM to accomplish the bulk charge, before there's enough sunlight to produce any significant solar power.
2. Shut down the generator at 9:00 AM, and let the solar system finish off the battery charge over the next 5-6 hours of strong sunlight.


Good post
Link Posted: 10/12/2013 8:29:33 PM EST
what is the deal w/ these alternator setups everyone keeps talking about.

I guess you are talking about rigging up an alternator to a genny. I get that.

Is that good for your batteries though? to just charge them w/ an alternator rather than a regulated three stage battery charger?

I guess it works for cars, but isn't the alternator more of a trickle charger? Is this a viable alternative for an AC fed high rate charger?
Link Posted: 10/12/2013 8:39:12 PM EST
[Last Edit: 10/12/2013 8:45:35 PM EST by EXPY37]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By rightwingnut:
what is the deal w/ these alternator setups everyone keeps talking about.

I guess you are talking about rigging up an alternator to a genny. I get that.

Is that good for your batteries though? to just charge them w/ an alternator rather than a regulated three stage battery charger?

I guess it works for cars, but isn't the alternator more of a trickle charger? Is this a viable alternative for an AC fed high rate charger?
View Quote




It's an excellent way to get charge into the batteries. It can be precisely controlled.

Check my topic on building one w/ pix on page 2. You can go to hundreds of amps with the right alternator and big enough battery bank.

But for the sorts of banks we talk abut here I'm looking at about 80 amps.

They have built in regulators, most not adjustable, that limits charge to about 14 volts, not enough for a full charge in a battery bank, but enough to get them ~75% charged.

The rest of the time, solar takes over and tops them off when they are at rest and the sun's shining.


Sure it's viable to an AC genny with a large charger, tho it depends mostly on application, and fuel resources, etc. A lot of things.

One very capable can be built inexpensively w/ a lawn mower type engine and a car/truck 50 to 120 amp alternator. Quick and easy to build. Otherpower IIRC, makes a couple parts to save time.


Here's the link...


Kubota/alternator


Link Posted: 10/12/2013 9:10:45 PM EST
[Last Edit: 10/12/2013 9:13:24 PM EST by Paul]
Link Posted: 12/11/2013 1:34:16 PM EST
interessting
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