eu20i charger, enough juice?

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System
System Posts: 2,511 admin
in Solar Beginners Corner #1
I'd like to know if a Honda eu20i can produce enough juice to charge a battery bank of 8 trojan batteries 305 Ah 6V.
It's my first step to be off grid because no utility service is available at my location but I can't afford buying the whole system, so I'll try to make it scalable.
I need 4 kw/h a day to operate my house.
I'm also planning the purchase of a Xantrex XW4024.
Later I'll start getting solar panels.
Thanks
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #2
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    Re: eu20i charger, enough juice?
    • Honda eu2000i
    • 8 Trojan batteries 305 Ah 6V.
    • XW4024
    • 4 kWH per day loads
    A few observations:
    • If you are planning on using the 4kW from the XW or charging on the order of 4kW from your solar panels/charge controllers, you should have an absolute minimum of 800 AH @ 24 volt battery bank for proper charging/discharging (currently your planned bank is 610 AH).
    • Double check the XW charger--I don't know if it will work with a 120 VAC genset or not (I am no XW expert).
    • XW has a very good internal battery charger--You will be adding the cost of an "extra" external AC battery charger if you put off purchasing the XW Hybrid inverter (but I do recognize the limitations of budgets).
    From a battery point of view, we aim at the battery bank designed for 3 day of no sun and 50% maximum level of discharge:
    • 4,000 WH * 1/24 volts * 1/0.85 inverter eff * 3 days * 1/0.50 discharge max = 1,176 AH @ 24 volts "nominal bank recommendation"
    • You could go to about 1/2 that value if you plan on running a genset more in bad weather--but that would still be less than the 800 AH recommend for a 4kW inverter system.
    From a charging point of view, we use a 5-13% of battery bank capacity (20 Hour Rate) as a good starting guide:
    • 1,176 AH * 0.05 = 59 amps minimum
    • 1,176 AH * 0.13 = 154 amps nominal maximum
    • 800 AH * 0.05 = 40 amps minimum
    • 800 AH * 0.13 =104 amps nominal maximum
    Battery chargers are typically around 0.80 efficient and most run at very poor power factors (0.6 or so)... So, to account for the generic charger, plan on operating genset at 0.50 of rated load for planning (use 29 volts for Vbatt charging):
    • 59 amps * 29 volts * 1/0.80 eff * 1/0.50 gen min = 4,278 watt rated genset
    • 154 amps * 29 volts * 1/0.80 eff * 1/0.50 gen min = 11,165 watt rated
    Note that the above has a 2x rated wattage to account for the fact that most AC charge controllers have a power factor of 0.6 (1.7x derating--poor power factor draws more current).

    If you have a good charge controller (like the XW)--it is possible that an eu2000i could keep an 800 amp 24 volt battery bank reasonably happy.

    Got to go now--Questions?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #3
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    Re: eu20i charger, enough juice?

    This is a viable "scalable" plan. In fact I often recommend people start with a small generator, and battery bank/inverter for "quiet power" at night. Adding panels later when you can afford them completes the task.

    Assuming you mean the Honda EU2000i inverter generator, it's capable of 2000 Watts, minus some loss depending on where you run it, how good the gas is, age et cetera.
    If I've calculated your battery configuration correctly, you will have 610 Amp/hrs @ 24 Volts. What model Trojan is 305 Amp/hr 6 V?
    Based on that, roughly 30 Amps minimum @ 28.4 Volts = 852 Watts, so there should be no problem with the 2000 Honda (remember you want to be able to run loads while charging).

    Speaking of loads, the best place to start planning a system is by calculating your potential loads. That will give you the information you need to size both the inverter and battery bank, and hence the charging system. If you have the equipment you want to run, pick up a Kill-A-Watt (type) meter and check its actual usage over time. It's an invaluable tool for getting some realistic figures to calculate your expected power use.
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  • RCinFLA
    RCinFLA Solar Expert Posts: 1,484 ✭✭✭✭
    #4
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    Re: eu20i charger, enough juice?

    XW inverters require 240vac from generator. Also the eu20i has an H-bridge output which does not provide for a groundable neutral.

    You can run the eu20i through an isolating step up transformer to solve both issues.

    I have a Yamaha EF3000i that I run through two Thordarson 23V608 isolation transformers. You would need one for a 2kW generator.

    You could also run two 1 kW 1:1 isolation transformers with primary winding in parallel and secondary winding in series to produce 240 vac.

    Need to set max charger draw on XW to not exceed eu20i output capability.

    http://www.alliedelec.com/Search/ProductDetail.aspx?SKU=7040057&MPN=23V608#tab=Specs
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #5
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    Re: eu20i charger, enough juice?
    RCinFLA wrote: »
    XW inverters require 240vac from generator. Also the eu20i has an H-bridge output which does not provide for a groundable neutral.

    Now that's odd, because my EU2000i works fine with a neutral-ground bond (at the breaker box only, of course). :confused: Why do they make so many changes?

    The XW requiring 240 VAC input is a problem, but as you say can be solved with a transformer.

    The point of my post was that the OP should start with the loads, and see if he even needs a 4 kW inverter or 610 Amp/hr battery bank. Hint: my sig shows what I run, and it's less inverter (still overkill) less battery (could stand to be a bit more) and works fine.

    Needs more panel. They always need more panel! :p
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  • RCinFLA
    RCinFLA Solar Expert Posts: 1,484 ✭✭✭✭
    #6
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    Re: eu20i charger, enough juice?

    You run the risk of blowing out the inverter in the generator with ground bonding neutral.

    If you do not also connect to generator ground prong (chassis of generator), letting generator chassis float, you run less risk to generator's inverter but have possible shock hazard from any metal screws on generator (most of the generator case is plastic).
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #7
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    Re: eu20i charger, enough juice?
    RCinFLA wrote: »
    You run the risk of blowing out the inverter in the generator with ground bonding neutral.

    If you do not also connect to generator ground prong (chassis of generator), letting generator chassis float, you run less risk to generator's inverter but have possible shock hazard from any metal screws on generator (most of the generator case is plastic).

    Hmmm.
    Well I've been using it this way for years and thousands of hours with both the old 1000 and the 2000 without any shocks, faults, fires, or failures. The bonding was necessary to get certain other equipment to report proper grounding (yes, the whole computer/satellite/office set-up). Maybe I'll re-examine the arrangement.

    Otherwise I don't think I'll worry about this "Phantom Menace". :p

    And if only someone would put this kind of info in the owner's manuals ...
    (I've just been looking. It mentions the lack of bond, but I haven't found any warnings specifically against it. Probably a defective manual. :p )

    But seriously, the lack of specific ground connection information for generators, inverters, et cetera is quite a problem. "Always be sure your unit is properly grounded" is a pathetic "legal out" in my opinion.
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  • System2
    System2 Posts: 6,290 admin
    #8
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    Re: eu20i charger, enough juice?

    Thanks for your answers.
    That 4kw/h day is what I consume on my current home, so I extrapolate that number to the new house.
    I'll move as soon as I could generate power enough.
    I saw the specifications' sheet of the Xantrex 4024, and it allows inputs of 120/240, so maybe a smart move is to get a Honda generator who produces 120V with Electric starter who can be automatically controlled by the Xantrex.
    In such way, it doesn't matter if I have a power reserve of two or three days. The only factor is gas consume.
    Am I wrong?
    Sorry for my English, but it's my second language.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #9
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    Re: eu20i charger, enough juice?

    Your English is fine. In fact it's better than that of many of my fellow countrymen for whom it is supposed to be a primary language! :D

    I read the spec sheet on the XW4024 and it looks to me like it will accept either 120 VAC input or 240 VAC input. :confused:

    The smaller generators of course do not support autostart. You'd probably have to have at least a 3 kW model to do that. Like a Honda EU3000iSA http://www.hondapowerequipment.com/products/modeldetail.aspx?page=modeldetail&section=P2GG&modelname=EU3000IS&modelid=EU3000ISAN

    (I'm sounding like a Honda advertisement - again! :p)

    Note that you say your usage is 4 kilowatt hours per day. That does not mean you need a 4 kW inverter. To properly judge the size of inverter you need to know your maximum loads. For instance, I use about 2.4 kW/hours per day. My inverter is sized large, because some of the things I run use a lot of power but only for a short period of time. It is in fact larger than I need, but if someone turns on everything at once ... 3000 Watts.

    And yes, keeping enough gasoline on hand is an issue. Fortunately these inverter-type generators are very fuel efficient even at less than 50% load. Mine will use 2 litres for a daily complete charge of the batteries. Yours would use more with a bigger bank and higher daily loads.
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  • retrodog
    retrodog Solar Expert Posts: 53 ✭✭
    #10
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    Re: eu20i charger, enough juice?

    The EU2000 is really only a 1,600W generator, with a 2,000W surge.

    We ran into that little issue on the Vectrix because it's right at the threshold of what it takes to charge the bike.

    I have a dual burner electric stove that is a great demo for the eco-friendly mode on the EU2000. I just plug it in and then turn on each of the burners one at a time. Each one causes the gen to rev up a notable amount. People get a kick outta that.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #11
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    Re: eu20i charger, enough juice?

    Even an eu3000i with electric start is really not setup for auto-start... Looked a year or so for something that could interface an eu3000i type genset and only found those that would work with a "key fob" push button remote start. There was not any thing that could take an "Run/Stop" signal from the typical generator controller (i.e., you have to hold the start button only long enough for the generator to start).

    You will need to get a generator (and/or controller) that will be able to interface with the available solar/inverter generator controller.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #12
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    Re: eu20i charger, enough juice?
    retrodog wrote: »
    The EU2000 is really only a 1,600W generator, with a 2,000W surge.

    And at 3000+ feet above sea level they're not even that! :cry:
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  • RCinFLA
    RCinFLA Solar Expert Posts: 1,484 ✭✭✭✭
    #13
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    Re: eu20i charger, enough juice?
    Cariboocoot wrote: »
    I read the spec sheet on the XW4024 and it looks to me like it will accept either 120 VAC input or 240 VAC input. .

    Check out page 1-7 of XW installation guide. Between bold lines in middle of page.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #14
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    Re: eu20i charger, enough juice?
    RCinFLA wrote: »
    Check out page 1-7 of XW installation guide. Between bold lines in middle of page.

    That clears that up!

    They ought to make that clear on the spec sheet as well - it's misleading.

    I'll remember that in future when I'm recommending other inverters over Xantrex. :roll:
    (Well it is a bit of a limitation, isn't it? Especially on smaller systems.)
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #15
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    Re: eu20i charger, enough juice?

    Honda Eu 1000 easily powers a Xantrex TC 20 (20 amp charger) into 12 volts. It won't quite power the TC 40 due to power factor issue.

    So at a minimum an Eu 2000 would power the TC 40 or an IOTA equivalent.

    Tony
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  • cfcw
    cfcw Solar Expert Posts: 25 ✭
    #16
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    Re: eu20i charger, enough juice?

    I have an EU2000 and Xantrex prosine 2.0. At the default factory setting the EU2000 would not charge the batteries. The charging circuit was drawing more amps than the generator could provide. However, the prosine has a menu function that allowed me to alter current capacity of the incoming AC line. I adjusted it down to 13 amps, and now the pair work fine together. It limits DC charging amps to the batteries to about 70 amps IIRC. To ensure that you setup will work correctly, I would verify that the charge rate or AC breaker size can be adjusted on the inverter you plan to purchase.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #17
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    Re: eu20i charger, enough juice?

    We're drifting a bit here, folks: the original issue was could a EU20i Honda charge 610 Amp/hrs of battery; it can.

    The OP was also considering buying the XW 4024 inverter. The secondary issue was then that you can't run that inverter's built-in charger from a 120 VAC generator.

    I suggest the OP get back to us with some info about his biggest cumulative likely load. This, together with his estimate of 4 kW hours per day consumption, gives us a better starting point for determining an inverter/battery bank combination that will work for him. Evidently he'd prefer one that would work with the Honda generator.

    He might be better off to buy the Magnum MS4024 http://store.solar-electric.com/maenms4040wa.html rather than the Xantrex unit if there's no need for 240 VAC.
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  • retrodog
    retrodog Solar Expert Posts: 53 ✭✭
    #18
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    Re: eu20i charger, enough juice?

    Well, whatever you end up doing, if you get a Honda EU2000... remember to open the gas cap valve before starting the thing. I got mine primarily for backup power during power outages (hurricanes and the like) and just run it a couple of times a year to keep it operational. Seems like the last two times I was going to start the darn thing, I completely forgot about the gas cap valve and left it in the "OFF" position. I couldn't get the thing to start for anything... till I figured out that darn valve was closed and caused the tank to vacuum and not feed gas. I opened the valve and the little generator started right up.

    So remember...

    OPEN THE VALVE!!!

    :p
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #19
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    Re: eu20i charger, enough juice?

    A couple of notes:

    The Honda EU generators are great ! In my opinion, the EU 3000i (not the Handi model) is the nicest of any of them, but, it does have a manual choke, so it may be hard to auto-start -- Had wondered about trying to start it on LP Gas (aka Propane), and shut off the LP when it started.

    Also, think that Honda rates the surge @ 30 minutes, altho I have not seen this stated very often, so this may be an error on my part. Honda does seem to be conservative on its generator ratings.

    I do LOVE those lil' Honda EUs. My only complaint is that the EU 6500isa will simply not toleaate the Xantrex SW+ 5500s while charging. The generator gets yanked out of regulation when one of the inverters takes a gulp of power on the generator's output (at 240 Volts). Good Luck, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,746 ✭✭✭✭✭✭
    #20
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    Re: eu20i charger, enough juice?

    Marc,
    The xw series must have a 240VAC generator or a cluge transfomer. If you do the single phase firmware (and mod) an xw6000 inv/charger can be run from 120VAC a generator. I do not beleive there is firmware and mod to do this on the xw 4524 or the xw4548.

    Your outback experience is a different animal BTW
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

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