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Topic: combining AGM and Lithium ..... please hear me first .... (Read 1159 times) previous topic - next topic
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combining AGM and Lithium ..... please hear me first ....

This is technical question and starting a new thread in technical forum rather than posting this delima in alaska trip thread ...  as I am filling in details in Alaska trip I realize that we will be in US and Canadian National parks for weeks and weeks without shore power :-( If push come to shelf we will deal with it with a smile but if I can make life little easy why not .... but before execution I want to see if I am going in the right direction. This is very new to me ...

Biggest power hog and problematic area is bipap machine humedifier ... I can turn the humedifier off for a day or two but shutting it down for weeks (especially when inside and outside temp difference is high) will have significant impact on my life style but it is not life and death but again looking for alternatives ... Bipap with humedifier depletes fully charged 500W battery pack in 6-7 hours means bipap (mostly humedifier) use on average of 500/12/6 (around 7 amp per hour, three times more then I estimated initially). Humedifier is no the only culpirt, my pressure settings are little high as well.

Now if I buy something like this Amazon.com: SCREAM POWER LiFePO4 Battery 12V 400Ah Up to 7000 Deep Cycle... and it is also available at ebay as well for little less ... it will give me 400ah for about 12-1300 dollars and life will be easy for few years. Problem is charging this monster battery ... I don't think foldable solar pannels will be enough ... tell me I am wrong, please .... and if you can send me a link for pannels which can keep this battery charged I will be very thankful. I will not be moving the battery it will be in the bed room (we have full bed setup which give some space between bed and sofa) and solar wires will be coming out of bedroom window.

Other option is to use the alternator and I am not ready to perform a major surgery and am not willing to put time in change the converter (to get more current out of the alternator). I have two six volt agm batteries connected in series under the fridge which are connected in parallel to batteries on the other side outside battery box. If I run the wire from the agm batteries sitting under the fridge and put a dc to dc charger in series and connect the wire to this monster 400ah battery, will this mechanism work? Of course I will always have to turn off dc to dc charger off when truck is not running and other unknown to me is if this dc to dc work just one way or both ways means is there any chance of current flow from lithium to agm batteries? Will stock converter and say 20amp dc to dc charger eliminate additional pressure on the alternator? Another unknown is current converter will create enough current to charge both coach batteries and one new battery.

Reason for this message was to pick your brain on why this is not a good plan. Hope this message is clear enough. I am not sold on this idea and can easily wait for agm battereis to die (and I will start abusing them now)  and at that time if we decide to continue with Lazy Daze perhaps I can find an expert to do the things in the right way. Our plans to get expedition vehicle and go out of US/Canada is not as charming as it used to be after we saw crime ridden places in South America. I think there is enough in US and Canada to keep us busy for rest of our life. In the best case senario we can goto Ausgralia and NZ and rent RV for couple of moths instead of having a headache dealing with shipping agencies, insurances etc. etc.

Regards,

As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.
Re: combining AGM and Lithium ..... please hear me first ....
Reply #1 –
May I suggest a solar generator?   I'm not happy with the generic name as there is no generation of any type from this setup just a battery with assorted plugs and doodads.   With the addition of a couple of solar panels this could be the solution you are looking for  Most solar generators come with a solar controller so you can connect the solar panel directly to the solar generator.

I have both a Jackery and Bluetti.  
Best BLUETTI Solar Generators: What Are They?
Jackery Best Solar Generator, Portable Power Station & Solar Panels

I would recommend the Bluetti as it has better chemistry and doodads. 

glen
personal fine art photo stuff
TF Mack | Flickr
It's all good .......
2014 Twin King
Re: combining AGM and Lithium ..... please hear me first ....
Reply #2 –
Thanks you are suggesting what I looking at for couple of weeks. Guess seeing 400ah power battery was tempting. Solar generators or battery packs if I am lucky perhaps I will get for 2000wh which will be close to 160ah.
Thanks for the validation.


Quote from: colddog  - 
May I suggest a solar generator?   I'm not happy with the generic name as there is no generation of any type from this setup just a battery with assorted plugs and doodads.   With the addition of a couple of solar panels this could be the solution you are looking for  Most solar generators come with a solar controller so you can connect the solar panel directly to the solar generator.

I have both a Jackery and Bluetti.  
Best BLUETTI Solar Generators: What Are They?
Jackery Best Solar Generator, Portable Power Station & Solar Panels

I would recommend the Bluetti as it has better chemistry and doodads. 

glen
Re: combining AGM and Lithium ..... please hear me first ....
Reply #3 –
Here's a suggestion about your BiPAP or CPAP: try using it with water in the reservoir, but with the humidifier (heater) turned off. You'll still get some humidification due to evaporation, but power consumption will be greatly reduced. This might be a workable compromise solution.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: combining AGM and Lithium ..... please hear me first ....
Reply #4 –
Quote from: Muhammad  - 
I will not be moving the battery it will be in the bed room (we have full bed setup which give some space between bed and sofa) and solar wires will be coming out of bedroom window.
I concur with Glen on the BLUETTI AC200P Portable Power Station, as it’s versatile in terms of charging and outputs, making it more useful to you and will cover what you need.  Your link has double the battery, but the Bluetti is also an inverter, has many inputs/outputs and far more user friendly for what you are attempting, especially at the last minute.

I’m assuming the back king bed in a MB is the same as my TK, width wise, with the same style couches.   If so, you should be able to use the space under the bed (couch) circled, hooking up the Bluetti to both the AC and 12v outlets for recharging purposes.  Then run your BiPAP cord to the Bluetti.   Occasionally you’ll run your generator to top off the Bluetti on days you don’t drive enough to recharge it.  Or just have it sit in the corner on the bed.

Your situation is exactly why I spent a pretty penny last May adding 400ah of Lithium, 850 watts of Solar, and a 3000 watt inverter.   My wife uses a CPAP with a humidifier, that, with StarLink I needed that much power.
Dave

2017 TK
Re: combining AGM and Lithium ..... please hear me first ....
Reply #5 –
Quote from: Muhammad  - 
Reason for this message was to pick your brain on why this is not a good plan. Hope this message is clear enough. I am not sold on this idea and can easily wait for agm batteries to die (and I will start abusing them now)  and at that time if we decide to continue with Lazy Daze perhaps I can find an expert to do the things in the right way.

In the best case scenario we can goto Australia and NZ and rent RV for couple of months instead of having a headache dealing with shipping agencies, insurances etc. etc.
Don’t get hung up on waiting for your AGMs to die before upgrading to LiON batteries.  AGMs aren’t fitting your RV use case needs.   My AGMs were still fine when I tossed them for my upgrade.

If you are considering a RV rental down under, a Bluetti makes even more sense, assuming it’s possible to ship them, since rental RVs are very likely NOT to have enough battery capacity for you.
Dave

2017 TK
Re: combining AGM and Lithium ..... please hear me first ....
Reply #6 –
Glen and Dave,

When knowledgeable folks talk I listen ..... and that is the reason I keep coming here and I do wish I can help somebody in future as well. I executed on your advice, it was not very expensive to think too much about it ....

I am dreaming about getting rid of propane and generator (along with four AGM batteries) ..... time will tell ... now new Lithium batteries whose power I will never use is  about 1K next phase should be size and weight amd more standard components to put them togather (we are seeing some of it in the battery pack)

Anyway, my horizon is short and instead of going for more famours brands and too many features I went for OK quality but made sure that batterytype  and solar material is familier to me.  I am not sure I need Y connector do I need it? and also not sure if solar controller is part of the pannel ... all the battery packs do have inverter built in but I dont think we have any 120V applience except for shaver and tooth past charger.

I know I need some kind of wire extension from solar controller which may be in the back of the solar pannel to bring power to the battery pack which would be in the bed room. As for bed room, we have the same setup as yours. We use one sofa and put a full bed on the other side. Both of us are not overly heavy and our travels keep us same way so full bed works. I you are aware of what kind of extention I need let me know. We have 15 days before we leave :-)

Re: combining AGM and Lithium ..... please hear me first ....
Reply #7 –
"I would recommend the Bluetti as it has better chemistry and doodads.  "

I have had a small Bluetti for a bit over a year now and find it quite useful for my 300-watt rice cooker, and my 45-watt Hot Logic.  This may not be usable for a CPAP machine, but it certainly has filled the bill for what I needed it for.

We didn't get a chance to try it out before he passed away, but we had acquired a 12-volt cable for my husband's CPAP machine.  In use with a stand-alone battery, power usage will likely be less by plugging in a 12-volt appliance rather than utilizing the conversion feature to take it to 110.

When deciding how to beef up my "power plant", I am looking hard at a high-capacity Anker unit.

Anker Portable Power Station Expansion Battery 2048Wh - Anker US

It has two particularly nice features which allow a 30 amp connection, as well as expansion modules.

When stacked up against the "features" of a fuel-using generator, it has great appeal.  But there are also many other considerations that tip the balance one way - and then the other - depending on the intended usage, and circumstances available for recharging with various methods.

If a generator is already in place, it could be utilized to recharge the Anker when it is propitious to run the generator, and then utilizing the "quiet power" of the Anker when it is "Quiet Time".

If solar panels are in place on the roof, having them charge the Anker during times when there is an abundance of rays would extend your ability to use power at night.

The battery on my Pleasure-Way is an 80-Ahr AGM, for a paltry run time of 40 Ahrs.  I'm thinking that by adding a good-sized Anker unit, I can start out with a fully-charged unit, and then combine input power from the 12-volt portion when driving, regenerating power when plugged in at a campground, running the generator (sparingly) if/as needed, and then observing if solar panels will be required.

The idea here is to leave the in-place power system to run the coach as was intended when it was built, and to provide an auxiliary source for all of the electrical doo-dads that we now find ourselves helpless to live without.

The biggest stumbling block, though, is SIZE.  The Anker is so huge that it has its own retractable handle and wheels for moving it around.  Still working on that aspect.


   Virtual hugs,

   Judie
Re: combining AGM and Lithium ..... please hear me first ....
Reply #8 –
Quote from: Dave Katleman  - 
Don’t get hung up on waiting for your AGMs to die before upgrading to LiON batteries.  AGMs aren’t fitting your RV use case needs.   My AGMs were still fine when I tossed them for my upgrade.

If you are considering a RV rental down under, a Bluetti makes even more sense, assuming it’s possible to ship them, since rental RVs are very likely NOT to have enough battery capacity for you.
Dave,
LD was a proof of concept and Alaska will be a good test case ... so far I was not spending any time on RV improvement but I am realizing how lucky we are to be here in this beautiful country in peace and friendly people and I do not have much desire to go out. Lets see how we feel after seven months togather in tight space :-)
Be well and I will be looking for you in Penensula .....
Re: combining AGM and Lithium ..... please hear me first ....
Reply #9 –
Judy,
These battery packs are just comodoties ... I have no name two 500 watt power packs and they have the same function as any other ones ... battery chemistry is important so is the solar pannel material (but I am not an expert here). As for bipap, it use 18 volt and I had a wire which convert 12V from coach battery to 18V, does not make sense to make the two changes and wate in between. Bipap pressure make some differnce but real deal breaker is humedifier .... my 500W did not last for more then few hours when I keep the same settings when I am at home or when we have shore power. Beside bipap I was very surprised that 95% of the campground from Glacier National park till we go to Palmer Alaska do not have shore power. Our AGM are two years old and not sure how much I can trust them and beside Bipap I was also looking for some assurance that we will not suck  for basic needs.

Nice to hear from you after a long time. Hope you are doing well and start travelling.

Regards,

Quote from: Judie Ashford  - 
"I would recommend the Bluetti as it has better chemistry and doodads.  "

I have had a small Bluetti for a bit over a year now and find it quite useful for my 300-watt rice cooker, and my 45-watt Hot Logic.  This may not be usable for a CPAP machine, but it certainly has filled the bill for what I needed it for.

We didn't get a chance to try it out before he passed away, but we had acquired a 12-volt cable for my husband's CPAP machine.  In use with a stand-alone battery, power usage will likely be less by plugging in a 12-volt appliance rather than utilizing the conversion feature to take it to 110.

When deciding how to beef up my "power plant", I am looking hard at a high-capacity Anker unit.

Anker Portable Power Station Expansion Battery 2048Wh - Anker US

It has two particularly nice features which allow a 30 amp connection, as well as expansion modules.

When stacked up against the "features" of a fuel-using generator, it has great appeal.  But there are also many other considerations that tip the balance one way - and then the other - depending on the intended usage, and circumstances available for recharging with various methods.

If a generator is already in place, it could be utilized to recharge the Anker when it is propitious to run the generator, and then utilizing the "quiet power" of the Anker when it is "Quiet Time".

If solar panels are in place on the roof, having them charge the Anker during times when there is an abundance of rays would extend your ability to use power at night.

The battery on my Pleasure-Way is an 80-Ahr AGM, for a paltry run time of 40 Ahrs.  I'm thinking that by adding a good-sized Anker unit, I can start out with a fully-charged unit, and then combine input power from the 12-volt portion when driving, regenerating power when plugged in at a campground, running the generator (sparingly) if/as needed, and then observing if solar panels will be required.

The idea here is to leave the in-place power system to run the coach as was intended when it was built, and to provide an auxiliary source for all of the electrical doo-dads that we now find ourselves helpless to live without.

The biggest stumbling block, though, is SIZE.  The Anker is so huge that it has its own retractable handle and wheels for moving it around.  Still working on that aspect.


   Virtual hugs,

   Judie

Re: combining AGM and Lithium ..... please hear me first ....
Reply #10 –
Muhammad,

Glad you’re ordering a more user friendly portable battery system, it should take care of your needs.

I’m not sure a portable solar panel makes all that much sense on your upcoming Alaska trip.  I’m expecting half the days to be rainy in Alaska, doesn’t mean it will, but in all the trip reports I’ve read, it’s rains a lot.

How many stay put days will you have vs travel days?

On travel days you won’t have much time to do solar charging  Yes, there will be sunlight much later the further you travel north, but there are still only so many peak charging hours.   So it’s only useful on stay put days.

By hooking up your FFpower inputs to both your 12V outlet and AC for charging, you should get enough recharge on travel days to top it off, and you can recharge on stay put days from either your generator or electrical hookups (if available).

I find portable solar panels to be great if you are sitting for a few days or more, but not worth the effort if you are on the go frequently.  But YMMV.

I know what you mean about proof of concept trips, my nine weeks out on the road last summer was both a shakedown/upgrade trip, as well as do I really enjoy being out on the road for months at a time evaluation.     All getting ready for a much longer Alaska trip this summer.     I hear ya on the close quarters part, my trip this summer was originally solo, but my wife decided a month ago to finally retire and join me on the trip.   Which I love, but I have concerns as she has never spent more than five consecutive nights in the RV, and never boondocking.   :o

Hope to run into you sometime this summer!
Dave

2017 TK
Re: combining AGM and Lithium ..... please hear me first ....
Reply #11 –
Dave valid points .... As I mentioned I do have two 500W battery pack and 100W folding pannels and aware of the headache of setup and moving the pannel with the shadow and keep an eye on the weather.

We will go fast till Glacier NP but driving day is not more than 150 miles. At Glacier NP we will slow down (when shore power will not be present). Will pick speed after Jasper and will slow down again at Palmer. After Fair Banks (we will be making a closkwise circle in penensula) we goto Dalton or not or if we go how much we can take the risk but after Fair Banks it will be fast coming back till we reach Ontario province and then we will take 3-4 weeks to enjoy Beautiful Canadian Provisional Parks and enjoy fall folliage (not sure how much WoW factor will be left after Banff and Alaska).

Alternator in new Chasis is pretty powerful (I will say it create same amount of current as our generator) but perhaps converter is the weakest link. When we drive the truck with in few hours house battery is full (to begin with I rarely see it below 85%,, only real power usage is watching Youtube or Netflix for couple of hours) and we can start charging other batteries with the cigrate lighter all over the coach. This time around I got 400W solar pannel with relatively high voltage which will reduce the waste and hope it will help as well. We can do so much working with the unknowns and that is the reason I am getting advice here ..... and part of unknown is also keeping us sharp ;-)

We are blessed that our spouses are able to travel with us ..... we continue to bicker (according to our kids) but it is part of the fun. My wife is also an engineer and when push comes she is not shy rolling sleeves. She got me out of the bed after 7 years :-)
Re: combining AGM and Lithium ..... please hear me first ....
Reply #12 –
Quote from: Andy Baird  - 
Here's a suggestion about your BiPAP or CPAP: try using it with water in the reservoir, but with the humidifier (heater) turned off. You'll still get some humidification due to evaporation, but power consumption will be greatly reduced. This might be a workable compromise solution.
Andy, thanks and will give it a shot.
Re: combining AGM and Lithium ..... please hear me first ....
Reply #13 –
Inclosed is an image of me testing my Jacerky hookup as an external power source.   It worked.  I could have used the Bluetti also but my Jacerky was just at hand.  I have two 100 solar panels in parallel that I use to charge the solar generators.  We use them mainly for cooking with our electrical appliances i.e. coffee pots, frying pan, and pressure cookers.  Oh and also charging out assorted electronic gear.  Bluetti has a wireless charging spot.

glen
personal fine art photo stuff
TF Mack | Flickr
It's all good .......
2014 Twin King
Re: combining AGM and Lithium ..... please hear me first ....
Reply #14 –
Mentioned before but we run a hybrid or dual battery system-225AH of FLA and 400AH of lithium. They are in parallel and controlled by a marine battery switch. The FLA interfaces with alternator and starts the generator. The lithium is charged by lithium AC chargers powered by the generator and can charge the FLA with generator off. We have a 1500 watt full house inverter integrated with a second transfer switch on the generator line. Two hundred watts of solar can charge either system.

The coach is setup for sitting not traveling therefore no need to charge the lithium from the alternator. Lithium charges at 100+ amps so generator runs are brief.

A major advantage is we can start the generator without knocking Starlink and all other electronics offline. It took a lot of effort but works very, very well.
Harry 2006RB
Re: combining AGM and Lithium ..... please hear me first ....
Reply #15 –
I am very pleased with the performance of the Bluetti AC 200P that I have been using for the past year. It is the "swiss army knife"(just my opinion) of portable generators with its extensive energy input and output capabilities. I use it for charging all of my delicate electronics and direct connect to my 30 amp service so I can run the microwave and coffee maker when no shore power available. The only caveat I will mention is that the beefy inverter draws approx. 24 watts when in use so the unit may not be  efficient for a continuous 120 volt connection. I turn the inverter off when I am not using 120 volt power. All of the USB A/C and fast charge C ports run off the 12 volt side so electronics charging is very efficient and the two induction charging pads on top of the unit reduce the need for connecting cords. I see on the Bluetti site that it is currently on sale for the $1300 which makes it a great buy!

Matt
2004 26.5 Island Bed. Gumby
2006 Jeep Wrangler Rubicon
Re: combining AGM and Lithium ..... please hear me first ....
Reply #16 –
Odd, we run TWO CPAPs, wo humidifier, powered by two led acid batteries and the batteries never dip below 80%.
Note our devices are 12v. If yours is not, maybe think about getting one?


I wrote about in 2016.
The Lazy Daze Companion: CPAP


Don & Dorothy
Sold our LD in June of 2023

Our boring always non-PC travel blog
Traveling Dorothy
Re: combining AGM and Lithium ..... please hear me first ....
Reply #17 –
Humedifier is the killer for the battery. I do turn off the humedifier when in RV ... always have sinus issues and humedifier will improve the lifestyle. Reading two possible solutions here and am thankful for input .....

Quote from: Don Malpas  - 
Odd, we run TWO CPAPs, wo humidifier, powered by two led acid batteries and the batteries never dip below 80%.
Note our devices are 12v. If yours is not, maybe think about getting one?


I wrote about in 2016.
The Lazy Daze Companion: CPAP



Re: combining AGM and Lithium ..... please hear me first ....
Reply #18 –
100 amp charger !!! I thought this will not work with build in fuse protection.

So when generator is running, you can withdraw 100amp from any of coach 120V socket? non of AC fuse trip? You are withdrawing 12000W. What is our generator capacity?

Thanks and I am interested in your system and a rough hand drawn circuit diagram will be very beneficial.

Quote from: hbn7hj  - 
Mentioned before but we run a hybrid or dual battery system-225AH of FLA and 400AH of lithium. They are in parallel and controlled by a marine battery switch. The FLA interfaces with alternator and starts the generator. The lithium is charged by lithium AC chargers powered by the generator and can charge the FLA with generator off. We have a 1500 watt full house inverter integrated with a second transfer switch on the generator line. Two hundred watts of solar can charge either system.

The coach is setup for sitting not traveling therefore no need to charge the lithium from the alternator. Lithium charges at 100+ amps so generator runs are brief.

A major advantage is we can start the generator without knocking Starlink and all other electronics offline. It took a lot of effort but works very, very well.
Re: combining AGM and Lithium ..... please hear me first ....
Reply #19 –
That is 100 amps of 12 volt power to the lithium batteries which would be 1200 watts from 120 volt powered chargers for lithium batteries. The 4kw generator provides the AC power. There is also a 40 amp FLA charger.

A 30 amp DC to DC charger is used to charge the FLA from the lithium battery. Very convenient as you can silently top off the FLA over many hours and recharge the lithium in a few minutes.

My goal is to provide 200 amps of 12 volt (14.3 volt) charging power. Smart battery chargers in parallel are not additive so I am still working on that. I have two 60 amp and one 80 amp charger.

I never drew a schematic of the system but this is a link to the thread we wrote while developing it. The lithium bank consists of two banks of two 100AH lithium batteries. Each bank has it’s own battery monitor and a 200amp circuit breaker.
2003 Roadtrek hybrid battery system - Class B Forums

I  have both a Roadtrek and a Lazy Daze. The Lazy Daze has 400AH of lithium. The Roadtrek has 100AH of lithium.

The lithium chargers are connected directly to the generator through on/off switches. As wired shore power cannot power the lithium chargers. I did add a dedicated shore power input plug for them. Rarely have a use for it.

Advantages are the FLA, which can handle freezing temps, are in their original tray. Lithiums are inside and warm. I am usually in 30F night time temperatures.
Harry 2006RB
Re: combining AGM and Lithium ..... please hear me first ....
Reply #20 –
Quote from: Don Malpas  - 
Odd, we run TWO CPAPs, wo humidifier, powered by two led acid batteries and the batteries never dip below 80%.
Note our devices are 12v. If yours is not, maybe think about getting one?
BiPAPs consume more power than CPAPs, even without the humidifier.   And ones for travel are few if any.
Dave

2017 TK
Re: combining AGM and Lithium ..... please hear me first ....
Reply #21 –
Quote from: hbn7hj  - 
That is 100 amps of 12 volt power to the lithium batteries which would be 1200 watts from 120 volt powered chargers for lithium batteries. The 4kw generator provides the AC power. There is also a 40 amp FLA charger.

A 30 amp DC to DC charger is used to charge the FLA from the lithium battery. Very convenient as you can silently top off the FLA over many hours and recharge the lithium in a few minutes.

My goal is to provide 200 amps of 12 volt (14.3 volt) charging power. Smart battery chargers in parallel are not additive so I am still working on that. I have two 60 amp and one 80 amp charger.

I never drew a schematic of the system but this is a link to the thread we wrote while developing it. The lithium bank consists of two banks of two 100AH lithium batteries. Each bank has it’s own battery monitor and a 200amp circuit breaker.
2003 Roadtrek hybrid battery system - Class B Forums

I  have both a Roadtrek and a Lazy Daze. The Lazy Daze has 400AH of lithium. The Roadtrek has 100AH of lithium.

The lithium chargers are connected directly to the generator through on/off switches. As wired shore power cannot power the lithium chargers. I did add a dedicated shore power input plug for them. Rarely have a use for it.

Advantages are the FLA, which can handle freezing temps, are in their original tray. Lithiums are inside and warm. I am usually in 30F night time temperatures.

Thanks you very much, did not realized you are putting 100 amp to 12V battery and not taking 100 amp from A/C system. Now it make sense.  Fortunately now we can buy 400 amp LifoPO battery around $1K, affordable both on pocket and on space. Let me diggest bit more of your message before I start executing. After reading responses yesterday, I took briefcase solar out of my equation, it is not practical, I will assume I will have shore power or generator till I am able to get perminant solution of more solar and replace agm batteries, whenever it may be. My wife counted the number of consecutive days without shore power and both of us were not very comfortable. I keep telling her that we do have generator and not to worry but I was not comfortable using generator in a nice quite environment. Thanks again ... If you post the link of dc to dc charger and lifo charger you are using it will save me some time otherwise I can research and use amazon ranking ....

Why you cannot use the AC sockets to connect battery charger and charge your Lithium battery? Is converter the bottleneck? If yes, can I take a low amp charger and save labour of connecting directly to the generator? What is converter capacity?

Thanks again
Re: combining AGM and Lithium ..... please hear me first ....
Reply #22 –
The links for all the parts are hidden in the thread.

This is the 50amp charger. Amazon sells the 30 amp model. It doesn’t show on a DC to DC charger search maybe because they haven’t paid anybody off. It is designed for a sailboat and includes an MPPT solar controller with automatic switching between solar and alternator.

Search for Kisae on DonRowe.com or Amazon.

Kisae DMT1230 or DMT1250

KISAE DMT1230 Abso 30A DC-DC Battery Charger | DonRowe.com

KISAE DMT1250 Abso 50A DC-DC Battery Charger | DonRowe.com

It is excellent, very programmable,  and highly recommended. A few in the RV world have found it but not many. I did see one in the display case of a solar installer in Quartzsite.
Harry 2006RB
Re: combining AGM and Lithium ..... please hear me first ....
Reply #23 –
You been very helpful. Thanks.

I will read the thread you documented your work and perhaps answer is there but I am stuck at the following words from your original message here "The lithium chargers are connected directly to the generator through on/off switches. As wired shore power cannot power the lithium chargers." Can you please  explain why lithium charger cannot be connected to AC sockets in the RV when generator is running?

Thanks


Quote from: hbn7hj  - 
The links for all the parts are hidden in the thread.

This is the 50amp charger. Amazon sells the 30 amp model. It doesn’t show on a DC to DC charger search maybe because they haven’t paid anybody off. It is designed for a sailboat and includes an MPPT solar controller with automatic switching between solar and alternator.

Search for Kisae on DonRowe.com or Amazon.

Kisae DMT1230 or DMT1250

KISAE DMT1230 Abso 30A DC-DC Battery Charger | DonRowe.com

KISAE DMT1250 Abso 50A DC-DC Battery Charger | DonRowe.com

It is excellent, very programmable,  and highly recommended. A few in the RV world have found it but not many. I did see one in the display case of a solar installer in Quartzsite.
Re: combining AGM and Lithium ..... please hear me first ....
Reply #24 –
Quote from: Muhammad  - 
Why you cannot use the AC sockets to connect battery charger and charge your Lithium battery? Is converter the bottleneck? If yes, can I take a low amp charger and save labour of connecting directly to the generator? What is converter capacity?

On a Rear Bath the generator line before the Automatic Transfer Switch is available under the forward dinette seat. The ATS is on the other side of the coach behind the power panel. There really is no need but if I want to I can lift the dinette seat and plug in an extension cord from an AC outlet to the lithium chargers. I have only needed to do that once.

The converter is 55 amps. I usually have it’s circuit breaker off as I have a Xantrex 40 amp FLA charger wired in also before the transfer switch. We are rarely on shore power but if I am I turn the coach to FLA power, turn on the converter and turn all other chargers off.

On the Roadtrek we have a Kisae 50 amp charger throttled to 40 amp to charge the lithium battery from the alternator.

Starting the generator without knocking everything offline is a major advantage. Total electrical system redundancy is nice. In the Roadtrek the FLA battery failed on a very cold night. We just flipped the switch to lithium and went back to sleep. Picked up a new FLA the next day and all was well.
Harry 2006RB