Generator charging batteries 2021 Isata 5 30FW

[TitanMike]

Originally Posted by msusslin

Thank you for your feedback. As far as I'm concerned, the converter is not the issue, it's the proper settings I might need to finetune.
I don't see a setup on our firefly to set the charger to Bulk mode, as the charger is set to Float.
Attachment 280656

Depending on the make/model of your converter (or combination Inverter/Charger) you may need to go to that device to change settings rather than via the Firefly.

The charger may be operating on factory defaults and is set for a smaller battery bank.

Out of curiosity, have you touched the "Gear" icon (Settings) in the lower LH corner to see if you can change the charge settings there? Had to ask.

[Phreak480]

Originally Posted by Chuck_S

It's helpful to think of the battery sucking power from the charge source and the strength of the sucking is based on voltage differential. An 11 volt battery will suck hard but since surface voltage increases rapidly this tapers off quickly. (Voltmeters only sense surface charged so a reading of 12.7vDC does NOT always indicate a full battery.) A charger voltage of 13.8v only results in a trickle charge. Smart chargers (and even my converter) boost their voltage to keep the differential high.

I read (somewhere) that taking a battery from 80% to 100% takes just as long as going from 20% to 80% which makes trying for a 100% battery a long process. WW2 diesel electric submarines had to run on the surface to charge their batteries and I also read it was common for them to run in the 20%-60% charge level. Batteries at this level absorb power very quickly.

-- Chuck

Your explanation is applicable to lead acid, but lithium batteries behave very differently. OP has lithium batteries in their coach.

[msusslin]

Originally Posted by TitanMike

Depending on the make/model of your converter (or combination Inverter/Charger) you may need to go to that device to change settings rather than via the Firefly.

The charger may be operating on factory defaults and is set for a smaller battery bank.

Out of curiosity, have you touched the "Gear" icon (Settings) in the lower LH corner to see if you can change the charge settings there? Had to ask.

This is the converter we have on our RV.

MagnaSine MS2812 Inverter / Charger with pass through, without a remote control installed.

Here are the Inverter/Charger settings set via our Firefly panel. I'm not sure what the absorption time setting should be, currently set at .1 hours.

[twp5253]

Yes, I said and meant plural. I have an extra Magnum Hybrid to run my fwd AC while tooling down the road. I opted to purchase the advanced remotes as that allows me to customize the charge parameters. One nice thing about having two is that allows me to charge my batteries quickly when on shore power but I don't find that much of a benefit. In fact, when on shore power, I usually turn the chargers off and let the solar keep the 600AH Li units up near 100% SOC

Now, boondocking and running the GenSet is a whole new ballgame because I can push some serious amperage into the Li batteries using both the Inverters/Chargers. Less time running the GenSet to get the pack up to 100%. THank you Greg for giving me a genset that is useable! Camp Dynamax for the WIN!

[TitanMike]

Originally Posted by msusslin

This is the converter we have on our RV.

MagnaSine MS2812 Inverter / Charger with pass through, without a remote control installed.

Here are the Inverter/Charger settings set via our Firefly panel. I'm not sure what the absorption time setting should be, currently set at .1 hours.

Attachment 280670

That question is best answered by the battery manufacturer. What brand are they?

An absorption time of only 6 minutes (.1 hr) seems inadequate, especially if your battery bank is not fully top balanced. For my 200 ah battery bank Battleborn recommends one hour (30 min/100ah battery). The purpose is to make sure the cells are fully balanced which only happens at the higher voltage, usually the charging voltage.

I seem to recall that FR was using Relion batteries at one time and if so Relion recommends 0-15 minutes of absorption time. Don't specify if that is for a single 100 ah battery or a group of 100 ah batteries in parallel.

FWIW, upping absorption time won't really speed up charging of your batteries but it will help ensure proper cell balance and max stored energy.

[twp5253]

Originally Posted by msusslin

This is the converter we have on our RV.

MagnaSine MS2812 Inverter / Charger with pass through, without a remote control installed.

Here are the Inverter/Charger settings set via our Firefly panel. I'm not sure what the absorption time setting should be, currently set at .1 hours.

Attachment 280670

I purchased one of these for each of my Magnum Inverters https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

By using the advanced features you can really control the way your Li battery bank gets charged. Unfortunately, Relion has not posted much in this area. BattleBorn has posted specific instructions using this remote I am pretty sure. I found a guy on YouTube that thought he knew how to setup the Magnum for doing a Li battery bank. Especially the part about long term storage at something close to 50% SOC.

[Captain Insaino]

Originally Posted by msusslin

We do get some solar charging during the day which will reduce the Amp usage during the day slightly, just not enough to recharge the batteries as they would under full sun. 800W in series panels on the roof.

LOL Nevermind. That's a lot of solar!

[toshu]

Originally Posted by msusslin

We do get some solar charging during the day which will reduce the Amp usage during the day slightly, just not enough to recharge the batteries as they would under full sun. 800W in series panels on the roof.

I think its time we got a group of Xplorer owners and did a detailed analysis of charging amps and watts. I can get up to 400 amps delivered to my batteries at times. HOWEVER, Dynamax has told me that the rear 4 panels are supposed to deliver up to 30% less than the front set because it has 12 ft of wiring

[Aussieguy]

Originally Posted by toshu

I think its time we got a group of Xplorer owners and did a detailed analysis of charging amps and watts. I can get up to 400 amps delivered to my batteries at times. HOWEVER, Dynamax has told me that the rear 4 panels are supposed to deliver up to 30% less than the front set because it has 12 ft of wiring

30% loss from wiring I'd say someone goofed?



if you getting power/voltage drop because of 12ft
look at increasing the wire's gauge ?


Especially if using a suitcase and you want a LONG distance from panel to battery

[msusslin]

Originally Posted by toshu

I think its time we got a group of Xplorer owners and did a detailed analysis of charging amps and watts. I can get up to 400 amps delivered to my batteries at times. HOWEVER, Dynamax has told me that the rear 4 panels are supposed to deliver up to 30% less than the front set because it has 12 ft of wiring

Good idea.

Do you get 400 amps from your solar panels? We have 800 W of panles on the roof.

I started this thread due to trying to understand generator charging times and proper I/C settings for the LI 400A battery bank, not the solar charging as that's working great.

We don't need to run the generator while boondocking if we have full solar.
We are planning a fall trip for 2 weeks staying at the North Rim of the Grant Canyon and the allowed generator run time is a total of 4 hours per day. Last time we stayed there we had maybe 20% of solar charging due to the beautiful tree coverage. As others we shut down the fridge at night to conserve power. However, to get the from 65% SOC to 100% SOC, it takes more than 2 hours of generator run time and I'm trying to figure out if that's normal or what I can do with the current setup to keep the batteries at 90%SOC.
Since the fridge is running during the day the solar charging is not sufficient to keep the batteries charged and by 4pm the batteries are at about 70% SOC and with the allowed 2 hours we can get them ready for the night.
Now running the RV engine does that trick in 1 hour.

Could you Xplorer gents share your I/C setting page to see if we all have the same settings. I have a call into Relion to ask for help.

[Aussieguy]

I still say you need a LOT of good professional help to get the best value from your investment.
Did you ADD the 400ah capacity or was it factory?
Did the Installers really look at what you got.

I'm not an expert
but I did notice your usage was -129 from blue phone screen
which I assume is reading directly the battery's APP


if that 129 is your average daily usage
it should NOT be that hard to setup a system to replace that!


400ah may be better used by splitting the bank ??
get a better charger ??
change the wiring on the batteries OR solar ??

[Mike946]

I was questioning the 8kw generator as well on our 28ssx. It seems the inverter charger only puts out 30 amps for us into the batteries. Can run the truck engine and get 140 easily.
I was thinking of putting a separate charger just dedicated for charging to use more of the generator capacity.
It does seem like a huge boat anchor if the only use (at least for us) is to charge the batteries when we have a more capable engine already on board.

[msusslin]

Originally Posted by Mike946

I was questioning the 8kw generator as well on our 28ssx. It seems the inverter charger only puts out 30 amps for us into the batteries. Can run the truck engine and get 140 easily.
I was thinking of putting a separate charger just dedicated for charging to use more of the generator capacity.
It does seem like a huge boat anchor if the only use (at least for us) is to charge the batteries when we have a more capable engine already on board.

Mike946, what firefly software version do you have and what are your I/C settings for your LI batteries.
The prior software version had a fault setting where the Generator as only charging at 20%. Software ver 4.6 fixed that. Additionally, the I/C settings need to be specifically set for the LI batteries, set under custom settings.

As Toshu mentioned we should all share our Xplorer firefly settings to find the best setups. I will ask my RV tech to figure out how to best use the Onan 8K capacity to its fullest.

[Chuck_S]

Can run the truck engine and get 140 easily.

Not a chance.

Note that batteries charge by voltage differential so to get 140 amps thru your wiring will take a literal short circuit. Battery at 11 volts (pretty dead) only has a 3 or 4 volt differential between it and the alternator and you're unlikely to get a high amperage flow. Without a shunt type meter on your system I can't even guess but with my "250 amp" alternator camper battery will draw 30 amps for a couple of minutes until the battery surface voltage increases and makes the voltage differential (and draw) much lower -- maybe 10 amps for a while until the voltage gets even higher. After that it's just a couple of amps at most.

Because the truck battery voltage is high the voltage regulator will keep amps low. Emergency vehicles use a separate alternator to run vital equipment.

Complete battery charge usually takes overnight on a good charger or a couple days drive if on the engine alternator.

DC to DC voltage booster is an option but there's no free lunch.

-- Chuck

[TitanMike]

Originally Posted by Chuck_S

Not a chance.

Note that batteries charge by voltage differential so to get 140 amps thru your wiring will take a literal short circuit. Battery at 11 volts (pretty dead) only has a 3 or 4 volt differential between it and the alternator and you're unlikely to get a high amperage flow. Without a shunt type meter on your system I can't even guess but with my "250 amp" alternator camper battery will draw 30 amps for a couple of minutes until the battery surface voltage increases and makes the voltage differential (and draw) much lower -- maybe 10 amps for a while until the voltage gets even higher. After that it's just a couple of amps at most.

Because the truck battery voltage is high the voltage regulator will keep amps low. Emergency vehicles use a separate alternator to run vital equipment.

Complete battery charge usually takes overnight on a good charger or a couple days drive if on the engine alternator.

DC to DC voltage booster is an option but there's no free lunch.

-- Chuck

What you are describing is typical for lead/acid batteries.

The OP's batteries are LiFePo4 batteries with low internal impedence. They'll draw as much current as the charging source will deliver. An alternator could deliver up to it's rated capacity minus any power used by the vehicle, limited also by connecting wire resistance.

DC-DC chargers are often used with LiFePo4 batteries to limit charge current, especially in motorhomes where alternator to battery distances can be short and wire gauges larger.

Charging with an engine mounted alternator, unless driving, is very inefficient fuel-wise.

Generators are far better but can only charge at max rate determined by inverter/charger or converter charger they are powering.

Sent from my SM-N950U1 using Forest River Forums mobile app

From online specs the OP's inverter/charger is rated for a max of 125 amp DC.

Should be able to recharge his 400ah battery bank from 100% DOD to 100% SOC in 4 hours max--- -----with proper settings. Pretty clear that THAT's the issue.

[bclemens]

Originally Posted by toshu

I think its time we got a group of Xplorer owners and did a detailed analysis of charging amps and watts. I can get up to 400 amps delivered to my batteries at times. HOWEVER, Dynamax has told me that the rear 4 panels are supposed to deliver up to 30% less than the front set because it has 12 ft of wiring

That's not exactly what we said....I know, because I am the one that said it.

"they are not supposed to" they just can have a variation based on certain factors.

1. The solar panels do not start charging until they are +5 volts from battery voltage. So, due to the length of run from the front panels vs. the rear panels, the front panels were going into bulk mode first. (as they were seeing a +5 voltage first) every time.

Also, the rear panels were not set up the exact same way as the front panels so there can be some variation there as well. I don't recall what my calculations ended up being....but I think 30% was an extreme case.

[Mike946]

Originally Posted by msusslin

Mike946, what firefly software version do you have and what are your I/C settings for your LI batteries.

The prior software version had a fault setting where the Generator as only charging at 20%. Software ver 4.6 fixed that. Additionally, the I/C settings need to be specifically set for the LI batteries, set under custom settings.



As Toshu mentioned we should all share our Xplorer firefly settings to find the best setups. I will ask my RV tech to figure out how to best use the Onan 8K capacity to its fullest.

I can't tell you as we are on the other side of the world, New Zealand. The answer will have to wait until April next year when we return.

[Chuck_S]

What you are describing is typical for lead/acid batteries.

Battery type makes no difference. Power flows based on voltage differential. Obvious extreme differentials are a short circuit ("infinite" difference) and a full charged battery (of any construction) with a infinitesimal difference between the battery and charging source.

A "12v" lithium ion battery has a fully charged voltage of 14.4vDC vs a lead acid battery's fully charged voltage of 12.7vDC.

Compare the two charts. Lithiums require much higher DC voltages to charge and these voltages are seldom available with DC generators and truck alternators. "Voltage drives the bus" and the voltage regulator in vehicles is kept low to avoid overcharging the vehicle battery.

Lithium

Lead acid


13.2vDC is the typical voltage output of a vehicle alternator. The Lithium chart shows this ain't gonna get that battery to full charge unless the differential can be increased.

-- Chuck

[Phreak480]

Originally Posted by Chuck_S

Battery type makes no difference. Power flows based on voltage differential. Obvious extreme differentials are a short circuit ("infinite" difference) and a full charged battery (of any construction) with a infinitesimal difference between the battery and charging source.

A "12v" lithium ion battery has a fully charged voltage of 14.4vDC vs a lead acid battery's fully charged voltage of 12.7vDC.

Compare the two charts. Lithiums require much higher DC voltages to charge and these voltages are seldom available with DC generators and truck alternators. "Voltage drives the bus" and the voltage regulator in vehicles is kept low to avoid overcharging the vehicle battery.

Lithium

Lead acid


13.2vDC is the typical voltage output of a vehicle alternator. The Lithium chart shows this ain't gonna get that battery to full charge unless the differential can be increased.

-- Chuck

Battery chemistry very much makes a difference. Lead acid batteries have a lower ability to accept charge as they progress towards full, and lithium can be charged at a high rate almost the entire time. Also we aren't talking about vehicle alternator charging, we are talking about the generator powering an inverter charger with a lithium charging algorithm.

[MNtraveler]

Agree with the comment that you shouldn't worry about getting to 99 or 100%. Just refill the batteries with the power you pulled from them. If you can charge them to the 12.4-12.5 range (tested after being off charge for at least 30 minutes), that is normally fine.


When plugged into shore power, the converter will fill the batteries to 100% but it may be over 2-3 days to completely charge them up. It's not needed for daily usage.