Generator charging battery

parbob1 · November 8

Battery charge time with Generator is my aprox math correct.

The battery manufacturer says
Voltage Setting 48 VDaily Charge (Absorption) 58.1Equalize 61.9Float 54.0
my Honda generator is limited to 21amps At 240V. hooked up to SW4048 to charge batteries

I have 48V X 470AH =22,560 watts and if I run the batteries to 70% I have to replace 6,800 watts
( these are net number that the ComBox shows going into and out of batteries)
So if my Generator is putting 56 volts and 2,200 watts per hour back to my battery bank then it should take about 3 hours to recharge my bank?

The ComBox and the battery monitor are not getting along, the BM is showing 95% SOC however the voltage is 48.1 and the hydrometer shows 60%-70% . I have disconnected the BM and going to fully recharge batteries then reconnect BM and adjust. Thanks Bob

Raj174 · November 8

Hi Bob,
Do you mean the SW charger voltage setting is 56 volts? If so, it will take much longer to charge the bank. I recommend setting to your stated absorb voltage of 58.1V. That way you will get the maximum current until the battery bank reaches absorb voltage. The charging time will be extended after the battery bank reaches absorb voltage because batteries will take less and less amperage as the batteries approach 100%. So foe example, discharging to 70% over 3 hours may take 4 to 4.5 hours to recharge. Also, I believe most battery monitors reset to 100% only when the absorb cycle completes.

Rick

mike95490 · November 8

Do you have an effiency number or Power Factor (PF) for the charger side of the SW ? That will influence what the generator can drive.

parbob1 · November 8

Rick. The SW is set at 58.1 bulk and 58.1 absorption for 180 min. I think that because my batteries are 13c temp the SW is limiting the charge..
I equalized the batt bank then hooked up battery monitor. Then ran a charge cycle.. I should have taken hydrometer reading before hookin up BM. .
todays project check hydrometer readings .. if needed recharge BB to full and then add BM and change setting on BM .. bob

Estragon · November 8

Maybe worth noting that at 13°C the bank will need a higher voltage absorb for proper charging. If the charger is set up to use a remote temp sensor, it should hold maybe 60-61v (rough guess) in absorb. If not, you may want to work our the compensated voltage and adjust manually.

BB. · November 8

The equation for calculating the actual charging voltage is:

(Batt Temp - Std Temp) * compensation value * number of cells = Voltage offset

For example of a typical flooded cell lead acid battery bank:

(13C batt temp - 25C standard temp) * -0.005 volts / C / Cell * 24 cells (48 volt bank) = +1.44 volt increase over Vbatt-std-chrg
59 Volt charge (FLA @ 25C) + 1.44 volts offset = 60.44 volts actual charging voltage

Note, many AC inverters have a 15/30/60 VDC limit on input voltage... You have to look around for AC inverters that are at least 16/32/64 VDC or so maximum input voltage (12 volt / 24 volt / 48 volt battery banks).

For our friends in the north, shutting down AC inverters during charging can be an issue in winter.

-Bill

parbob1 · November 8

Yes today went from good to bad. The Inverter compensated for the 13-15c battery temp and the absorption voltage was 59.6. My hydrometer showed a 1.25 adv reading then I hooked up the BM
.. the Battery temp sensor then read 50c . When in fact the batteries were 14c
attached 2 device reports. If you look you will see to different tempature from the same BTS

. Is anyone fluent in Schneider ComBox?

My emails/tech support or Schneider go unanswered and the people who sold me the system are unable to help, ( but very good about answering my calls or email). I am having lots of issues with my Schneider equipment

t00ls · November 10

parbob1 said:

I have 48V X 470AH =22,560 watts and if I run the batteries to 70% I have to replace 6,800 watts

heres the problem I am seeing lately...DC amps and AC amps can not be used interchangeably ....they are different

when you are using 1 amp AC.....you are probably using 2 or 3 amps dc

also, you cannot use wattage for how long a battery will last.....you have to use amps....that is why renewable energy batteries are expressed in AH amp hours....or how long a battery will last drawing 1 amp an hour.....it wont work saying you are drawing 1 watt an hour

so to figure out how long it will take to fully charge your batteries you need to know what the charge amperage is

there is a formula to figure this out...dont remember where it is...but I can tell you if you have 470 AH of 48v battery bank...it will take 4-6 hours to charge at 30 amps...at 90 amps...which is what I think the conext SW 4048 will charge at with a generator supply power....then it will take maybe 3 hours to get to float.....unless you set your absorb time lower, default should be 180 minutes

I dont recommend charging at 90 amps....it will destroy a battery if it is done all the time
batteries like to take a charge slow....and in return the battery power will last longer also the battery will last longer

when needed, as a battery starts to sulfate, make sure to do a real good equalize charge with higher voltage and higher amperage...this is to break up the sulphation

t00ls · November 10

the other thing is....your generator may be limited to 21 amps....AC

the inverters built in charger will put out 90 amps ...DC

as I said above...the 2 are completely different as long as you have your generator sized right for your inverter....you should size the gen larger than your inverter size to allow for surge wattage

the 4048 should have a 6000 to 9000 watt generator...any smaller and you run into surge problems

mike95490 · November 10

t00ls said:

........................t he 4048 should have a 6000 to 9000 watt generator...any smaller and you run into surge problems

Well, that all depends on if you configure things properly. While re-jucing my NiFe bank over 9 days, I ran nights on a eu2000 and a autotransformer. Never a bit of problem. And my regular generator is only 3kw. When you program it properly, it just works !

parbob1 · November 10

after watching manny videos on ComBox and other Schneider products and accessories i see one common thread....
no one use the ComBox to set perimeters.. they all us Conext SCP. You watch the video and the ComBox sits on the wall and goes unmentioned.. all you here is “push this button three time to home screen” on the SCP.
the set up menus on the ComBox and the owner’s manual are not the same ..many setting have like terms but are located in different set up section.
For example my BTS is reading two different temps. ( see earlier post).

Thinking the problem is the “default temp”. I looked through owner’s manual, and it is not found ) and the ComBox will not let me change setting
I hoping someone has Schneider products and can help.. as most of you who have commented have other manufactures equipment... maybe I picked the wrong horse.

mcgivor · November 10

How many temperature sensors are being used? Rationale being, there may be conflict between more than one reading. One sensor should share the information via Xanbus to al other devices.

parbob1 · November 10

mcgivor , I am Only using 1 BTS. According to owner manual “ if more than on BTS is used.. the higher temperature will be used”.
FYI I have updated the firmware on all of my devices, the AGS is removed from the system for the time being.

If the BTS is plugged into inverter I get the above results. If the BTS is plugged in BM the temp reads 70c and the whole system shuts down. I have tried two different BTS and get same results
thanks Bob

mike95490 · November 11

1) are all the proper xanbus terminations installed at both ends of the bus ?

2) i routinely use both combox & SCP to make measurements and change settings. both work well, and I've not seen any negative interactions in the system.

If I'm running the generator, I use the SCP to ramp up the charging amps as the generator warms up. If I'm in my office, I use the combox over wi-fi to adjust any settings. I have summer and winter settings that I alternate between.

parbob1 · November 11

Mike, yes all the proper xanbus terminations installed., and thank you it’s good to hear system will work properly. Bob

Estragon · November 11

Might be worth checking the RTS jacks. A bit of crud/corrosion or bent jack conductor can do this sort of thing, and in my experience phone and ethernet type jack connections are prone to this. I've seen some pretty high-tech system problems eventually solved with a Q-tip and contact cleaner.

parbob1 · November 12

Cleaned all of the jacks and switched positions same outcome. I’ve asked for a replacement BM

Generator charging battery

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