Generator newbie question?

[Lakesidemn]

I currently have a RoadTrek Sprinter that charges the coach batteries with the "underhood generator", plus solar. I'm not familiar with traditional generators.

I'm currently looking at a Leisure Travel Serenity with two 6V coach batteries and a 3.6kw LP Onan. I'm wondering how fast the Onan should charge the two coach batteries? Also, would the engine alternator charge the coach batteries? It does have a 200w solar panel, but I know they take a lot of time to charge. Thanks.

[rowiebowie]

Originally Posted by Lakesidemn

I currently have a RoadTrek Sprinter that charges the coach batteries with the "underhood generator", plus solar. I'm not familiar with traditional generators.

I'm currently looking at a Leisure Travel Serenity with two 6V coach batteries and a 3.6kw LP Onan. I'm wondering how fast the Onan should charge the two coach batteries? Also, would the engine alternator charge the coach batteries? It does have a 200w solar panel, but I know they take a lot of time to charge. Thanks.

Engine generators will charge coach batteries. An Onan generator is good for when you need to power your A/C or microwave, and will charge the Serenity coach batteries as well. But, unlike lithiums, lead batteries take a long time for that final 5-10% top-up. So a generator is not ideal for charging. We plug in overnight every few days to make sure coach batteries get a full charge. Otherwise, even when driving, they are only 90-95% charged some days. No problem getting through the night, however.

Remember, almost anything you get will have less battery power and inverter capacity than your Roadtrek.

[Lakesidemn]

Originally Posted by rowiebowie

Engine generators will charge coach batteries. An Onan generator is good for when you need to power your A/C or microwave, and will charge the Serenity coach batteries as well. But, unlike lithiums, lead batteries take a long time for that final 5-10% top-up. So a generator is not ideal for charging. We plug in overnight every few days to make sure coach batteries get a full charge. Otherwise, even when driving, they are only 90-95% charged some days. No problem getting through the night, however.

Remember, almost anything you get will have less battery power and inverter capacity than your Roadtrek.

I'm going to visit with the LTV sales guy again about this, but do you know if the AC or microwave can operate while the vehicle is running? If you have a Serenity, do they allow the geni to run while the vehicle is running? Thanks!!

[rowiebowie]

Originally Posted by Lakesidemn

I'm going to visit with the LTV sales guy again about this, but do you know if the AC or microwave can operate while the vehicle is running? If you have a Serenity, do they allow the geni to run while the vehicle is running? Thanks!!

I do not own a Serenity, but to my knowledge, no RV except those with separate under-hood generators (designed to replace the traditional coach generator) add the capacity to run appliances while driving.

Onan states it is ok to run their generators while driving.

.

[booster]

Originally Posted by rowiebowie

I do not own a Serenity, but to my knowledge, no RV except those with separate under-hood generators (designed to replace the traditional coach generator) add the capacity to run appliances while driving.

Onan states it is ok to run their generators while driving.

.

Most of the van before the standalone engine generators had 50 or 80 amp circuits from the engine alternator. Unfortunately, the inverters, if they had one, tended to be too small to run much over 500 watts, and they were modified sine wave.



Roadtreks since they went to separators was at 80 amps and that is just short of what it takes to run the Dometic microwave. It definitely will reduce how much you use out of your batteries. You need at least a 1500 watt PSW inverter to reliably run the micro IMO.



The only issue would be if you keep tripping the auto reset breakers in the wiring, which will often cause the inverter to drop out if you have a big enough one to actually supply the microwave.

[GBail]

Since the lp genny would take a really long time to fully charge up your coach batteries, here’s my solution....

1. Have easily accessible battery charging terminals linked to your system and installed on the inside of your rig.

2. Buy a small, portable fast charging battery charger.

3. When needing to charge up your coach when boondocking, start the genny, plug in your portable charger, attach the charger’s cables to the new terminals and charge away....

You can also do this on shore power when camped at a park with electric hookups of course.

I did this after I found out from the manufacturer of my rig that the best way to charge my batteries was not via the propane generator as it would take too long to do it that way.

I was told that, without this separate portable battery charger set up, because of the low speed of charging batteries by running power through my coach’s converter, the order of charging effectiveness would be:

1. Driving the rig, 2. Hooking up to shore power, and 3. Using the genny.

[NFRicaS]

A friend told me I could run my generator while driving..2004 Pleasure Way..have only run it while parked..just curious..true?

[booster]

Originally Posted by GBail

Since the lp genny would take a really long time to fully charge up your coach batteries, here’s my solution....

1. Have easily accessible battery charging terminals linked to your system and installed on the inside of your rig.

2. Buy a small, portable fast charging battery charger.

3. When needing to charge up your coach when boondocking, start the genny, plug in your portable charger, attach the charger’s cables to the new terminals and charge away....

You can also do this on shore power when camped at a park with electric hookups of course.

I did this after I found out from the manufacturer of my rig that the best way to charge my batteries was not via the propane generator as it would take too long to do it that way.

I was told that, without this separate portable battery charger set up, because of the low speed of charging batteries by running power through my coach’s converter, the order of charging effectiveness would be:

1. Driving the rig, 2. Hooking up to shore power, and 3. Using the genny.

I guess I don't understand what benefit you get with the "faster" charger, unless you have a very old fixed voltage converter in the van. All this assumes non lithium batteries, however.



The vast majority of the long charging times has to do with the acceptance rate of the lead acid batteries, not the chargers unless they are horribly too small or too low of a voltage. The batteries will start to taper what they will accept by 70-80% SOC, depending on how big the charger and batteries are, and by the time they get full, the batteries will only be accepting .5-3% of the capacity in ah in amps. High end for 20ah of batteries would 6 amps which is pretty small, low end would be 1 amp.


It will take 6+ hours in most cases to go from 50% to full on lead acid batteries, and the charger isn't going to get rid of that time, so that is a long generator run.


What van, charger(s), batteries do you have? How are you keeping track of what your state of charge is?

[booster]

Originally Posted by rowiebowie

Engine generators will charge coach batteries. An Onan generator is good for when you need to power your A/C or microwave, and will charge the Serenity coach batteries as well. But, unlike lithiums, lead batteries take a long time for that final 5-10% top-up. So a generator is not ideal for charging. We plug in overnight every few days to make sure coach batteries get a full charge. Otherwise, even when driving, they are only 90-95% charged some days. No problem getting through the night, however.

Remember, almost anything you get will have less battery power and inverter capacity than your Roadtrek.

What shore charger are you using in your van? I don't recall if you have a battery monitor.

[GBail]

Tried to reply at length to the questions about using the separate portable battery charger but the buggy forum website wiped out my answer

[GBail]

Originally Posted by NFRicaS

A friend told me I could run my generator while driving..2004 Pleasure Way..have only run it while parked..just curious..true?

When I had my Forest River Lexington B210 I was told I could more safely run my GAS generator while driving to keep my 2 way (110 and propane) fridge cold, rather than running it on the propane, since having the propane tank open while driving was not recommended.

So, yeah, if you have a gas generator, it sounds like it’s okay to run it while driving....but I wouldn’t do that with a propane one.

[GBail]

Originally Posted by booster

I guess I don't understand what benefit you get with the "faster" charger, unless you have a very old fixed voltage converter in the van. All this assumes non lithium batteries, however.



The vast majority of the long charging times has to do with the acceptance rate of the lead acid batteries, not the chargers unless they are horribly too small or too low of a voltage. The batteries will start to taper what they will accept by 70-80% SOC, depending on how big the charger and batteries are, and by the time they get full, the batteries will only be accepting .5-3% of the capacity in ah in amps. High end for 20ah of batteries would 6 amps which is pretty small, low end would be 1 amp.


It will take 6+ hours in most cases to go from 50% to full on lead acid batteries, and the charger isn't going to get rid of that time, so that is a long generator run.


What van, charger(s), batteries do you have? How are you keeping track of what your state of charge is?

I have a 2011 Provan Tiger, with two AGM (I think) 6V golf cart batteries to power the needs of the coach. Battery health is monitoring by a wall mounted digital readout that shows charging levels and output. I also have a 125W solar panel on the roof, with its own separate monitor panel also showing battery charge/output levels.

I never had any problem keeping the batteries charged while driving or while plugged in at a park with shore power, but while boondocking, they ran down after about three days due mostly to the use of a compressor fridge. The single solar panel wasn’t enough to keep them charged up while they were being used while dry camping, and running the propane generator for a few hours didn’t fully charge them back up either.

The manufacturer told me that the generator wasn’t actually the best way to fully recharge the batteries, unless I ran it for many hours, because the power from the generator runs through the 12V converter and that slows down the charging rate.

Supposedly, the system is set up this way to protect your coach batteries from being overcharged while staying hooked up in a park and leaving your rig plugged into the shore power.

So the solution suggested to me was to figure out how directly hook up a portable, quick charge battery charger directly to the coach batteries, and then run that charger while it’s plugged into a wall outlet in the rig with the propane generator running.

Basically, by doing it this way, the time to charge the batteries would be about half the time or less than it would take to charge the batteries just running the genny and powering the charge through that slow converter. It’s the same concept essentially as plugging a battery charger in in your garage and hooking it up to your car battery when your car battery needs a boost.

I hope that helps explain things a bit better.

[Bud]

Originally Posted by GBail

When I had my Forest River Lexington B210 I was told I could more safely run my GAS generator while driving to keep my 2 way (110 and propane) fridge cold, rather than running it on the propane, since having the propane tank open while driving was not recommended.

So, yeah, if you have a gas generator, it sounds like it’s okay to run it while driving....but I wouldn’t do that with a propane one.

If the b has an inverter, I can't think of a reason to run the generator. Well, if more a/c is needed than the inverter can provide which would not be a refer.

Bud

[GBail]

Yeah, mine did not have an inverter.....thus the generator use suggestion.

[booster]

Originally Posted by GBail

I have a 2011 Provan Tiger, with two AGM (I think) 6V golf cart batteries to power the needs of the coach. Battery health is monitoring by a wall mounted digital readout that shows charging levels and output. I also have a 125W solar panel on the roof, with its own separate monitor panel also showing battery charge/output levels.

I never had any problem keeping the batteries charged while driving or while plugged in at a park with shore power, but while boondocking, they ran down after about three days due mostly to the use of a compressor fridge. The single solar panel wasn’t enough to keep them charged up while they were being used while dry camping, and running the propane generator for a few hours didn’t fully charge them back up either.


As a point of reference, we have 440ah of Lifeline AGM batteries and can charge from the alternator at 200 amps continuous (until it starts to taper due to battery acceptance) or from a 100 amp Magnum shore charger. To get to true full, where the batteries are only accepting .5%C (2.2 amps) from under 50% SOC takes a minimum of 8-10 hours on charge.


The manufacturer told me that the generator wasn’t actually the best way to fully recharge the batteries, unless I ran it for many hours, because the power from the generator runs through the 12V converter and that slows down the charging rate.

Supposedly, the system is set up this way to protect your coach batteries from being overcharged while staying hooked up in a park and leaving your rig plugged into the shore power.

So the solution suggested to me was to figure out how directly hook up a portable, quick charge battery charger directly to the coach batteries, and then run that charger while it’s plugged into a wall outlet in the rig with the propane generator running.

Basically, by doing it this way, the time to charge the batteries would be about half the time or less than it would take to charge the batteries just running the genny and powering the charge through that slow converter. It’s the same concept essentially as plugging a battery charger in in your garage and hooking it up to your car battery when your car battery needs a boost.

I hope that helps explain things a bit better.

I understand what you are saying, but it really doesn't make any sense to me.


I can't imagine that any manufacturer in 2011 would use a single stage charger, and that is the only way I can think of that would make it so slow. It would also make it so the batteries would never get full. Of course many/most 3 stage chargers don't get the batteries full a lot of the time either, but they go to float so even better for the batteries than a fixed charger unless it is extremely low voltage.


What charger are you using for the quick charger? Do you know what charger they put in the Tiger? It would be very interesting to know, I think, to try to understand.


How much time are you talking about for charging to full and how do you monitor your state of charge? We have heard of lots of different charging setups on the forum, but I think this is a first for this kind of operation, at least that I remember.


As a point of reference, we have 440ah of Lifeline batteries and can charge at 200 amps off the alternator or 100 amps off the shore charger. To get from under 50% SOC to true full (.5%C amps or 2.2 amps to the batteries) takes a minimum of 8-10 hours on charge.

[GBail]

I feel like I’m hi jacking this thread so I’ll keep my reply short.

As to: “What charger are you using for the quick charger? Do you know what charger they put in the Tiger?”

These are questions I cannot answer at the moment as my rig and gear in it are in offsite storage for the winter.

As to: “How much time are you talking about for charging to full and how do you monitor your state of charge?”

I’m not as technologically educated as some of you guys, so I’m not sure I can answer this accurately. My digital wall readout and my solar monitoring display tell me what my current battery output is....anywhere from @ 14.1 to 12.5 or so (these numbers are from my memory from last trip). I understand that when the numbers are in the high 13’s my batteries are in good charge and functioning properly and when the numbers drop to the high 12’s I’m needing to recharge them.

I’ll return to this discussion to add more information the next time I go over the check up on my stored Tiger.

[booster]

Originally Posted by GBail

I feel like I’m hi jacking this thread so I’ll keep my reply short.

As to: “What charger are you using for the quick charger? Do you know what charger they put in the Tiger?”

These are questions I cannot answer at the moment as my rig and gear in it are in offsite storage for the winter.

As to: “How much time are you talking about for charging to full and how do you monitor your state of charge?”

I’m not as technologically educated as some of you guys, so I’m not sure I can answer this accurately. My digital wall readout and my solar monitoring display tell me what my current battery output is....anywhere from @ 14.1 to 12.5 or so (these numbers are from my memory from last trip). I understand that when the numbers are in the high 13’s my batteries are in good charge and functioning properly and when the numbers drop to the high 12’s I’m needing to recharge them.

I’ll return to this discussion to add more information the next time I go over the check up on my stored Tiger.

Sounds good, thanks, all information is valuable.