Recharging Battery w/Honda 2000i

[Zardoz-ESC]

Anyone have an idea how long it takes to recharge a single 12V battery at 50% capacity (12V's) up to 100% capacity (12.6V's) using a Honda 2000i generator?

 

[padlin]

I never had the patience to let it go to 100%. As it goes beyond roughly 90% the charge rate goes slower and slower. I also had 2 batteries so I can't give you a good answer. I let mine run for about 4 hours before the noise drove me to turn it off.

 

[Bobbito]

We have 2 deep cycle 6 volt batteries in our Escape 21. When boon docking and the batteries get very low, we find that running the Honda 2000i for 3-4 hours brings the capacity high enough to last 2-3 days unless it is extremely cold and the furnace is running a lot. As already stated, a full charge is impractical on a generator and would take days.
Bob K


Sent from my iPhone using Tapatalk

 

[rubicon327]

Anyone have an idea how long it takes to recharge a single 12V battery at 50% capacity (12V's) up to 100% capacity (12.6V's) using a Honda 2000i generator?

This is a loaded question and difficult, if not impossible, to answer even with more information. It is highly dependent on the battery amp-hrs and the converter charging amperage. A more practical concern might be how long it would take to get to 80% capacity (roughly 12.4V) since typically the final 20% of charge takes much more time and there are likely limits to how long you want to run a generator to charge batteries. In reality I would guess in this situation you are operating your batteries in the 40-80% charge range which doesn't maximize your usable amp-hrs, but may get the job done. With the charging system on most RV's I would guess most of us are operating here even if we don't think so. I don't think it hurts the batteries, unless you go too low, too often.

The only real world experience I can offer is similar to Padlin & Bobbito, but with a Scamp. Single deep cycle group 24 battery, Progressive Dynamics PD9130 converter (similar charging characteristics to the Escape stock WFCO 8955) and Honda EU2000i gen. Extending boondocking with no solar. Had to use the gen every couple of days (cold temps-furnace running) when returning from fishing and it took multiple hours (at least 3) to get the battery up to ~80%. We were in a remote field not bothering anyone. If this had been closer to people it would not be very courteous to say the least.

If you haven't seen this before the 12 Volt Side of Life is a great write up on the topic of low voltage power, batteries, charging, etc.:
The 12volt Side of Life (Part 1)

 

[Brian B-P]

The Honda EU2000i has a 12-volt DC output which can be used for battery charging, but it is very limited (only 8 amps as I recall) and is a very poor charging source. Since the trailer has a 55-amp converter/charger (in recent models), the way to go is definitely to plug the trailer into the generator's 120 V AC outlet and let the converter/charger handle it.

Since the converter/charger only needs about 700 watts to run at full output, and the EU200i can put out much more than that continuously, the generator is not a limiting factor. It will take the same time to charge the battery with the generator as it would plugged into shore power.

The Group 27 (standard) and Group 29 (optional) single batteries offered by Escape, at 50% discharged, are only 50 amp-hours short of being fully charged.

Since the converter/charger can put out 55 amps, from 50% to nearly fully charged shouldn't take much more than an hour (if you're not using much 12 volt power for other things at the same time). It's that "topping off" time (after the end of the bulk charge phase) that takes a long time. Lead-acid battery charging is far from perfectly efficient - more than an amp-hour must be put in to increase the charge level by one amp-hour - but that inefficiency doesn't double the time required.

I agree that it doesn't make sense to completely charge the battery on a generator. Getting most of the way there in a reasonable time seems like a better use of the generator... that seems like a couple of hours at the most, for the single battery.

 

[Zardoz-ESC]

Thanks!

Well, it's clear that my ignorance was showing but that's a small price to pay for enlightenment. I really appreciate everyone's thoughts and comments. Once again, many thanks.

 

[rubicon327]

Since the converter/charger can put out 55 amps, from 50% to nearly fully charged shouldn't take much more than an hour (if you're not using much 12 volt power for other things at the same time).

Brian...I had thought about the 55 amp rating of the WFCO, but it seemed highly unlikely to me that that is the actual charging rate. I've seen battery charging rates recommended at maximum C/10 with C being amp-hours. That would put us at say 9-12 amps for a single 12V battery (depending on group #). It is my guess that the WFCO is not putting out anywhere near 55 amps (and if it is, not for very long) and that is a reason for longer charge times involved. Obviously overall battery bank amp-hrs need to be considered too. Thoughts?

 

[Brian B-P]

Brian...I had thought about the 55 amp rating of the WFCO, but it seemed highly unlikely to me that that is the actual charging rate. I've seen battery charging rates recommended at maximum C/10 with C being amp-hours. That would put us at say 9-12 amps for a single 12V battery (depending on group #).

C/10 (one tenth of the capacity, or a full charge over ten hours) is a good rate for charging a battery... but there's nothing about the battery which makes this a limit: if you push it with more voltage, then more current flows. It's the same as discharging: it's best for efficiency and battery life to keep power used from the battery at something moderate such as C/10 (so, yes, 9 to 12 amps for an Escape's single 12 V battery), but if you can certainly take it out much faster (over 100 amps when using a 1500 watt inverter at full load, for instance).

Automotive starting batteries (about the same size as the smallest Escape battery, but constructed to handle higher currents for shorter times) can discharge at a few hundred amps, but chargers for them are routinely limited to 15 amps or so... because that's a good rate for charging. Still, a small charger often has a "fast charge" or "boost" mode at two or three times that current, in case you don't want to wait all day for a charge.

It is my guess that the WFCO is not putting out anywhere near 55 amps (and if it is, not for very long) and that is a reason for longer charge times involved. Obviously overall battery bank amp-hrs need to be considered too. Thoughts?

The converter/charger capacity is probably chosen to be high enough to handle any expected DC loads, (such as running all the lights, and the furnace, and the water pump), not for rapid charging; however, the converter/charger has no way to "know" whether it's running lights or charging a battery. A charger puts out as much voltage as necessary to push its rated current output, until it climbs to a set voltage (14.4 volts at the end of the bulk phase according to the WFCO manual)... and then charging slows down because the charger's reduced output voltage (13.6 volts for absorption according to the WFCO manual) is pushing against the battery's internal voltage which is still rising. A small enough battery could have enough internal resistance to limit the current to less than the WFCO's rated output, even at the bulk charging voltage... so I suppose a charger could be oversized for the battery. In that case, it might never take the full charger output current.

The WFCO charger's rated output is 55 amps. If it can only sustain that at a low voltage, then charging could certainly be slower as the voltage rises; however, the WF-8955 specs include an output power of 940 watts - that would be 55 amps at 17 volts, so WFCO says it can certainly sustain charging voltages at the full 55 amps.

 

[rubicon327]

Brian...thanks for all the info. My father is using the trailer as we speak on a steelhead fishing trip off Lake Erie. No solar (yet). He is running the Honda EU2000 about an hour and battery voltage goes from 12 to 12.5. Seems pretty reasonable for dual Interstate 6V's. Based on this timeframe the amperage must be pretty high as you have indicated.

 

[Ray B.]

This question will show my lack of experience. How do you attach the Honda generator to the trailer to charge the batteries?

 

[SFDavis50]

Plug the trailer power cord into the generator. The trailer comes with an attached cord and you can get the removable power cord as an option. Also may need a pigtail to go from the 30 amp to the regular 3 prong outlet.

 

[Karen H.]

This question will show my lack of experience. How do you attach the Honda generator to the trailer to charge the batteries?

While I think it more efficient to hook the generator directly to the battery terminals with alligator clips, the very few times I have used a generator I just plug the cord (same one that came with the trailer) into the generator.

 

[Brian B-P]

This question will show my lack of experience. How do you attach the Honda generator to the trailer to charge the batteries?

I'm suggesting that you plug the trailer's "shore power" (30 amp, 120 V AC) power cord - the one you would normally plug into an outlet at a serviced campsite - into the generator. You'll need an adapter, since the EU2000i only has regular 15-amp outlets (the same as the ones your house), not the 30-amp RV style of outlet. The trailer's converter/charger will then charge the battery.

There is also a 12 V DC outlet on the EU2000i, which could be used with suitable cables to connect directly to the trailer's battery; however, I'm suggesting that you not do that because the 12 V DC outlet cannot provide much power.

 

[Brian B-P]

While I think it more efficient to hook the generator directly to the battery terminals with alligator clips, the very few times I have used a generator I just plug the cord (same one that came with the trailer) into the generator.

Plugging the shore power cord into the generator actually works better, as explained above.

It might be more efficient to use the generator's 12 volt output (because there are fewer electronic devices involved converting power from one voltage and frequency to another), but it's not very effective.

 

[padlin]

FWIW... Don't know if things have changed, but the one time I hooked my Honda up to the trailer the surge protector tripped. I don't recall the error code, may have been an open ground, but it was a wiring mismatch of some sort. Seem to recall you could make a cheater plug or some such although I just turned off the surge protector to proceed.

Does anyone know if this is still the case?

 

[gbaglo]

Just plug the shore power cord into the outlet on the generator.

 

[Patandlinda]

FWIW... Don't know if things have changed, but the one time I hooked my Honda up to the trailer the surge protector tripped. I don't recall the error code, may have been an open ground, but it was a wiring mismatch of some sort. Seem to recall you could make a cheater plug or some such although I just turned off the surge protector to proceed.

Does anyone know if this is still the case?

Bob found the same , surge tripping . My brother made me the cheater plug , still tripped . Had to shut down surge for gen to run . We have a older 1000 watt Honda gen . Pat

 

[padlin]

Suppose mine might be an "older" generator too, it's roughly 8 years old.

 

[rbryan4]

This question will show my lack of experience. How do you attach the Honda generator to the trailer to charge the batteries?

It's providing AC power, so think "how do I attach the trailer to AC power?" The answer is, via your trailer's power cord.

Since your trailer power cord has a 30 Amp plug, and there isn't a 30 amp receptacle on the Honda 2000, you need a 30 amp to 20 amp adapter - sometimes called a dogbone. Plug your trailer power cord into the adapter, and the adapter into the generator. Your trailer's charger will do the charging of the batteries.

Having said that, the Honda doesn't have a 30 amp receptacle for good reason - it can't provide that much power. It still should be sufficient to run the air conditioner however, as long as you don't try to run much else. For just charging the batteries, it will work fine, albeit a bit slow.

When it comes to a generator, the simplest way to think of it is, it's shore power that you can move.

 

[Patandlinda]

Suppose mine might be an "older" generator too, it's roughly 8 years old.

Got you beat Bob 24 years old ,metal case and still looks new too . Pat