Ideals to charge a 48 volt batter bank

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gww1
gww1 Solar Expert Posts: 963 ✭✭
in Off Grid Solar & Battery Systems #1
I have a 48 volt, 800 amp hour fork truck battery. 5600 watt solar array.

I have a cheap 5000 watt generator and a 3500 watt generator.

I would like to keep my batteries from disconnecting during low sun periods due to low voltage.

I have heard that cheap generators are too dirty to use battery chargers on.

I was hoping this was wrong as I would like to eventually build a wood gassifier to try one of the generators with.

My system works fine for daily use but would not keep me going for more then one cloudy day if I ever had to count on it.

Any ideals?
Thanks
gww
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #2
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    Re: Ideals to charge a 48 volt batter bank

    I don't know who told you generators are "too dirty" to use battery chargers on, but they're not. They produce a true sine wave with very little harmonic distortion. The major problem with standard gens is that the Voltage and frequency can fluctuate as the load changes and affects the RPM of the engine. Usually this is a momentary problem.

    You may be mistaking using a charger for the problem of connecting such a generator to certain inverter's AC inputs which are expecting grid power. In that case the variation in V & F cause the inverter to drop the gen as the power is outside of specifications.
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  • gww1
    gww1 Solar Expert Posts: 963 ✭✭
    #3
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    Re: Ideals to charge a 48 volt batter bank

    coot
    I just read today that cheep generators don't do well with battery chargers. I read it in two different places. I haven't bought a charger yet and this seems to be my weakest point in my current system.

    I have outback and realize that only inverter generators have a chance of working with it for ac power. I just already have these generators and I also am not scared to ruin one of them expeirmenting with wood gas, that is if I get off my butt and actually do it.

    I thank you for setting me strait on being able to use a battery charger with my cheap generators. I feel more confident of keeping my eyes open for an oppertunity to pick one up now.
    Thanks
    gww
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #4
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    Re: Ideals to charge a 48 volt batter bank

    Once again Coot is right on. You have two Outback GVFX's with the best chargers in the world and all you have to do is hook a input from the generator and charge away if they work, Outback chargers are known to be rampy when they cut in. You can adjust the ACin to the breaker size on the Generator and adjust the charger output if necessary. If they are not completely insatlled as your sig suggests, no problem, cut the Inverter off. Now the output could be to dirty for them, that you'll have to see. You can start out slow and put minimum loads or no loads and cut the charger way back and see if you can get them to hold the generator. Anytime you start a load and be careful not to dump a large load on them. If the Inverter drops the generator it should try to re-connect. You also have generator support that can help with the loads if you cut the ACin back.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #5
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    Re: Ideals to charge a 48 volt batter bank

    Interesting point: the gen support feature may actually make the standard generators work better with the GVFX, depending on which reacts faster to load change: the inverter (good) or the generator (bad).

    AC input parameter tolerances can be adjusted somewhat.
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #6
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    Re: Ideals to charge a 48 volt batter bank

    I'd first to say it might be iffy with sudden load changes, but with a little patience, it there could be a work around. You never know the understanding of the people that have tried it.
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  • gww1
    gww1 Solar Expert Posts: 963 ✭✭
    #7
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    Re: Ideals to charge a 48 volt batter bank

    Blackcherry
    I should change my signature as I have had my stuff installed since about Oct. of last year. I was thinking that if I go through the battery and it was low, it would take all the battery charger would put out and when my well pump (2000 watts) kicked on the generator would not even notice. I realize the conversion losses, (ac to dc to ac) but would only need it in emergancy or to play with, ergo the wood gas.

    I don't really want to wire the generator to the inverter unless I get an inverter type generator cause I haven't heard of any one being succesful using no name generators. I could be wrong though.
    Thanks
    gww
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #8
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    Re: Ideals to charge a 48 volt batter bank
    gww1 wrote: »
    Blackcherry
    I should change my signature as I have had my stuff installed since about Oct. of last year. I was thinking that if I go through the battery and it was low, it would take all the battery charger would put out and when my well pump (2000 watts) kicked on the generator would not even notice. I realize the conversion losses, (ac to dc to ac) but would only need it in emergancy or to play with, ergo the wood gas.

    I don't really want to wire the generator to the inverter unless I get an inverter type generator cause I haven't heard of any one being succesful using no name generators. I could be wrong though.
    Thanks
    gww
    Thats your call to make. Your stand alone Charger should work fine. People that post that may be correct, but you never know what they tried and what they expected. I have no doubt it wouldn't start a 3 ton A/C, but if it will qualify it, it might pull a charger.

    People say that a Honda EU 2000 won't start a OutBack FWX-240 transformer, but it will if you pre magnetize the core with a resistance load first in series for a second or two.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #9
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    Re: Ideals to charge a 48 volt batter bank

    Well I've powered my VFX from a clunker gen, but it expects wide-variance gen input.

    No problem powering a stand-alone battery charger from one. Not the most efficient thing in the world but it will work if needed.
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  • gww1
    gww1 Solar Expert Posts: 963 ✭✭
    #10
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    Re: Ideals to charge a 48 volt batter bank

    I don't know which would be faster, the generator or the inverter. I do know that the lights flicker when the well pump kicks on and they strobe when my hot water is flashing on and off through the auxillary from the charge controller. This makes me think the inverter is a bit slow though I know it will handle an amazing amount of stuff.
    Thank
    gww
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  • gww1
    gww1 Solar Expert Posts: 963 ✭✭
    #11
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    Re: Ideals to charge a 48 volt batter bank

    You guys have answered my questions.
    I might one day just try going through the inverter. I am thankfull that I can use a stand alone battery charge as even if not the best, it is something I can do if needed.
    Thanks
    gww
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #12
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    Re: Ideals to charge a 48 volt batter bank

    Part of that is your Battery choice, while traction batteries have a long life, they tend to be slow to release current and hard to charge. On a lift truck you just push the accelerator harder, thats hard to do on a Inverter you get a voltage sag and lagging current.

    I notice a difference when I switch my Inverter from a GC-2 bank and a bank of Surrettes 4000 series 2 volt. The Surrettes kind of lag.
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  • gww1
    gww1 Solar Expert Posts: 963 ✭✭
    #13
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    Re: Ideals to charge a 48 volt batter bank

    blackcherry
    I wish I had bought a bit bigger battery. I am not complaining as the battery and inverters have ran everything I try to run. I have seen 5500 to 6000 watt peak pulls for short periods with out a hitch. I can live with a bit of light flicker as I put this together myself and didn't know what to expect, it works ok to me.
    Thanks
    gww
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #14
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    Re: Ideals to charge a 48 volt batter bank

    You do have a big system, maybe a nice 7-10 KW water cooled 1800 rpm generator would help you at times. I have a old 9 KW Onan Marine generator I converted to stationary use that can run forever. It was converter to a electronic governor before I got it, a friend had removed it from a boat for a larger one.
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  • gww1
    gww1 Solar Expert Posts: 963 ✭✭
    #15
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    Re: Ideals to charge a 48 volt batter bank

    blackcherry
    I have what I have listed in my signature installed. I did not install the homemade solar. I also have the grid so it is not imparitive that I get more stuff going. It just hurts my pride that I can't run if I wanted to with out the grid. I have not did any conservation so I deserve what I get. I do think that if I could charge at about 1000 watts an hour 24/7 I could run for the 10 or 12 days before the batteries would need a full charge. I don't think I want spend the gas or cut the wood to do this but would like to have the stuff to have the abilitie. I would like to try and use the stuff I already have to get this done as I still look at it as sort of expermenting and piddling. I love hearing your thoughts though.
    Thanks
    gww
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #16
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    Re: Ideals to charge a 48 volt batter bank
    gww1 wrote: »
    blackcherry
    I have what I have listed in my signature installed. I did not install the homemade solar. I also have the grid so it is not imparitive that I get more stuff going. It just hurts my pride that I can't run if I wanted to with out the grid. I have not did any conservation so I deserve what I get. I do think that if I could charge at about 1000 watts an hour 24/7 I could run for the 10 or 12 days before the batteries would need a full charge. I don't think I want spend the gas or cut the wood to do this but would like to have the stuff to have the abilitie. I would like to try and use the stuff I already have to get this done as I still look at it as sort of expermenting and piddling. I love hearing your thoughts though.
    Thanks
    gww
    I am sure you can, just throttle back your loads a little. I run a generator a lot at night with the A/C and then use the Inverter charger, it will raise and lower it's output as the A/C cycles. After you get up into the night the A/C doesn't run much and all the power go's to the charger and batteries. It's kind of a management thing.
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  • gww1
    gww1 Solar Expert Posts: 963 ✭✭
    #17
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    Re: Ideals to charge a 48 volt batter bank

    Blackcherry
    Thank you for your responces. I am headed home now and don't have internet so wont be able to respond anymore today.
    gww
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #18
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    Re: Ideals to charge a 48 volt batter bank

    I use a 1920's style generator, with sloppy freq control, and less than perfect voltage regulation. But if I feed that 240VAC power into the GEN input of my inverter, it gladly accepts it and runs loads and charges batteries with it. You may need to play with the programming of your inverter, but it's easily done.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    #19
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    Re: Ideals to charge a 48 volt batter bank
    mike95490 wrote: »
    I use a 1920's style generator, with sloppy freq control, and less than perfect voltage regulation. But if I feed that 240VAC power into the GEN input of my inverter, it gladly accepts it and runs loads and charges batteries with it. You may need to play with the programming of your inverter, but it's easily done.

    The OP has an outback GVFX inverter. They are much less tolerant of sloppy frequency control than the VFX inverters. I'm not sure how much they can be adjusted to accept sloppy power... BC04, what say you?

    btw, Outback makes a GFVX inverter with a "LA" suffix (latin america) which will accept sloppy power. It is NOT listed for use in north america.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #20
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    Re: Ideals to charge a 48 volt batter bank

    I have no direct experience with mine anything other than a Honda EU 2000 and a 20 kw Generator, both work fine. The one thing you cannot adjust on the Inverter is the HZ of the input because it's bi directional . Memory says it's 59.3-61.2 range, maybe less. That means you'd have to keep the RPM very stable on a non Inverter Generator and load and unload it very slow to keep it in range. So, I'd test it unloaded and gradually load it and see when it drops. If your only use the charger, thats where I start. Set it real low and keep adding more amps.
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