Newbie Power/Battery Questions

[tpc66]

Hello all - I'm a new 19D owner with a couple of electrical questions that have me stumped. I previously had a 35' Class A Georgie Boy that was the most simple machine in the world, so my new (to me) Navion has me a little puzzled.

The coach batteries were original, so based on some research and recommendations, I switched to Epoch Lithiums this past week. The installation went well, I changed the battery type on my Zamp solar and the batteries are charging.

My issues are related to the Inverter, Converter and Alternator.

- My understanding is that if I start the motorhome, the alternator will charge the house batteries. I'm monitoring the Epoch's via the App, and when I start the coach, there's no change in charging at all.

- I started the generator, turned on the circuit breakers (including the converter), and once again, no change - I thought the converter would also charge the batteries, as that's what it used to do on my GB Class A.

- The inverter (again, to my understanding) will provide 110 power to AC based appliances - in essence, I should be able to run the microwave when it's turned on. When I power up the inverter and look at the outside display, it shows 13.3V on the first screen, but 0.00 on the 2nd (which tells me there is either no output or no draw).

Apologies for what may be a simple response, but this has me stumped. I have not yet hooked up to shore power for fear of blowing something before I make some kind of configuration change.

I've read all the manuals on my inverter and converter, and I see nothing about any type of lithium changes that need to be made.

Devices installed are:

- Zamp Solar
- Progressive Dynamics PD9245C Converter
- Magnum CSW1012

Any help or guidance is greatly appreciated!

[d23haynes57]

I don't know what a 19D is. If one of the sprinter or Ram based van conversions these usually do not have alternator house battery charging ability. For the Mercedes adding this is often limited to 40 amps. Adding Lithium, you would need to add this capability using a DC-DC charging system. If the vehicle spec is a 40-amp limitation that really limits you to a 30-amp charger.

Also have to wonder why you would have a separate power converter/charger and inverter? Does the inverter have a pass-through relay? Being separate there has to be some appliances that only work on generator or shore power and some for the inverter. What size is the inverter?

[creativepart]

Lots to unpack here. But here’s an easy first comment. That’s a 1000w (max) inverter. It will never run the microwave, the toaster oven, the electric coffee maker, or anything with resistive heating. Those devices use more than the maximum that inverter can put out… no matter how many amp hours of battery you have installed.

In fact, Winnebago doesn’t even wire that inverter to high load outlets in places like the kitchen or microwave cabinet.

Also, your manuals are all written for the lead acid batteries your RV was built with. So, there wouldn’t be any instructions for changing to Lithium Iron Phosphate batteries. If you want to make that kind of change it’s all on you to do the necessary research and modifications necessary for such a change.

The Converter you have is not set up for Lithium batteries, you will need to change out the Converter to the Progressive Dynamics PD69R or other capable model to add a proper charging profile for LFP batteries. Also you should research the topic of charging LFP batteries with your stock alternator. The majority of experts discourage that practice.

There is a lot to learn about RV electrics, batteries, inverters, Converters and charging. But you’ll find a great deal of info on these topics on forums and especially on YouTube.

https://www.youtube.com/watch?v=mvSCNvk2hcA

[OMMM4747]

My understanding is that a non-Li to Li upgrade is not a simple plug-n-play. Inverter modifications are required if the existing one is capable of said modification, and if not capable, a new inverter and possibly converter combination may be required.

Presuming everything was working as designed before the Li upgrade, I'd say you're not completely done w/the conversion. Hardware/software mods and/or new equipment are likely in your future. If true, I'd recommend a professional. Incorrect electrical modifications can not only fail and/or cause damage to other equipment, they can be also be catastrophic.

Good luck

[tpc66]

Yep I had watched this video prior to the conversion - his inverter is capable of handling lithium so it was an easy reconfigure. I have a feeling mine is not and will probably need to be swapped out. Everything I've found so far has no reconfiguration instructions for the converter or inverter, so my guess is that they are not lithium compatible.

Originally Posted by creativepart

Lots to unpack here. But here’s an easy first comment. That’s a 1000w (max) inverter. It will never run the microwave, the toaster oven, the electric coffee maker, or anything with resistive heating. Those devices use more than the maximum that inverter can put out… no matter how many amp hours of battery you have installed.

In fact, Winnebago doesn’t even wire that inverter to high load outlets in places like the kitchen or microwave cabinet.

Also, your manuals are all written for the lead acid batteries your RV was built with. So, there wouldn’t be any instructions for changing to Lithium Iron Phosphate batteries. If you want to make that kind of change it’s all on you to do the necessary research and modifications necessary for such a change.

The Converter you have is not set up for Lithium batteries, you will need to change out the Converter to the Progressive Dynamics PD69R or other capable model to add a proper charging profile for LFP batteries. Also you should research the topic of charging LFP batteries with your stock alternator. The majority of experts discourage that practice.

There is a lot to learn about RV electrics, batteries, inverters, Converters and charging. But you’ll find a great deal of info on these topics on forums and especially on YouTube.

[oldenavy]

Above comments are spot on. Your RV apparently wasn’t built with Lithium in mind, so you will have to change out additional components to make it work as you desire. The 1000w inverter is just for charging your phone and running the TV. It won’t run any appliances. However, you don’t need to change any settings on an inverter for Li batteries. The converter is another story. Yours puts out a fixed 13.6VDC, not high enough to fully charge your new batteries. If they are totally depleted, you will get a partial charge but won’t ever get to cell balancing.

One additional thought. You said it wasn’t charging when on generator or engine running. Is that from an app for the batteries? Were they depleted when you tried it? If they are already full, it doesn’t matter what charging source you connect, they won’t take a charge if they are already full.

[tpc66]

EDIT/UPDATE: Thanks everyone - the advice given here (and also on the one of the facebook groups) led me to the following:

I tested my inverter directly at the inverter on the GFI - it's working fine - test light works as it should and the inverter starts to show current drawn on the display when the light is one.

My converter is not capable of charging lithium properly - I will upgrade to a newer unit.

My Microwave wasn't working off of the generator because (sad to say) I had not fully seated the power cord into the receptacle in the storage compartment. Hey - we all make mistakes, right?

As far as the alternator, I'll have to dig into that one further to see if I need to make changes/updates.

Thanks again for all of the advice and assistance! I like to consider myself pretty intelligent, but sometimes we go down a path and get so focused on something, the answer escapes us.

[Persistent]

That is a good plan!

Given the current configuration, thing may work okay.

Solar
The solar controller will charge and balance your new lithium batteries just fine.

Converter/charger
Shore power or generator power charge through the same converter/charger or inverter/charger. The charger will charge the lithium almost completely. The charger will not balance the cells.

The batteries do not need to be fully charged and balanced on every charge cycle, so the solar controller will complete the function when it gets enough sunlight.

If the solar system is charging the almost fully charged or fully charged lithiums at 14.4 volts, the converter/charger will not add anything. The lead acid charging profile will usually be applying a lower voltage of 13.6 or so. This does not hurt anything. The solar will finish the job.

Alternator
Alternator charging will work similar to converter/charger. It will charge the batteries to almost full. It will not balance the lithium cells.

The alternator is vulnerable to overload when lithium batteries are deeply discharge and charging fast. A 200 amp hour lithium bank may draw 100 amps from the alternator. If it does for more than a few minutes, the alternator may get hot and fail. The alternator is most vulnerable when not moving and engine is idling.

There are several solutions. The easy one is to disconnect alternator charging of the house lithium batteries.

There are several types of limiting devices including DC to DC chargers that will limit total current and provide the full charge and balance. Each method has advantages and limitations.

[tpc66]

Great information - thank you! I'm not too worried about the alternator - most of the camping we do is in a campground and 99% of the time I'll be hooked up to shore power, so I don't foresee running the batteries down very far. That should offset the need for a higher amperage charge from the alternator, but either way I'll keep an eye on it!

Originally Posted by Persistent

That is a good plan!

Given the current configuration, thing may work okay.

Solar
The solar controller will charge and balance your new lithium batteries just fine.

Converter/charger
Shore power or generator power charge through the same converter/charger or inverter/charger. The charger will charge the lithium almost completely. The charger will not balance the cells.

The batteries do not need to be fully charged and balanced on every charge cycle, so the solar controller will complete the function when it gets enough sunlight.

If the solar system is charging the almost fully charged or fully charged lithiums at 14.4 volts, the converter/charger will not add anything. The lead acid charging profile will usually be applying a lower voltage of 13.6 or so. This does not hurt anything. The solar will finish the job.

Alternator
Alternator charging will work similar to converter/charger. It will charge the batteries to almost full. It will not balance the lithium cells.

The alternator is vulnerable to overload when lithium batteries are deeply discharge and charging fast. A 200 amp hour lithium bank may draw 100 amps from the alternator. If it does for more than a few minutes, the alternator may get hot and fail. The alternator is most vulnerable when not moving and engine is idling.

There are several solutions. The easy one is to disconnect alternator charging of the house lithium batteries.

There are several types of limiting devices including DC to DC chargers that will limit total current and provide the full charge and balance. Each method has advantages and limitations.

[tpc66]

A final update on this - I was about to order a new converter but thought I'd check with Progressive Dynamics first - here's what they said:

PD9200 Lead Acid Charger use with LiFePO4 (Lithium) Battery.
It is not directly compatible. But can be used manually.
To use the PD9200:
Use the Pendant (PD92201) and press the button to give the Lithium a good charge when necessary.
It will not do it automatically .
Pressing it once a month is recommended for Lithium. When pressed it will give 14.4 VDC for 4 hours.

[SafariBen]

Will Prowse, the Li guru, says batteries need to be balanced "every few months" so not as critical as people on here make it out to be. If you have solar it will balance the batteries once they're full, so could be everyday if you plug in all night, or whenever you're not using it.



The alternator needs to be protected, not just "they'll be full most of the time". That protection can be as simple as a longer medium gauge wire serving as a resistor to limit the current to an absolute max of 50A or so. The Li will never drop to a low voltage, so resistance to limit the current is easy.

[tpc66]

Originally Posted by SafariBen

Will Prowse, the Li guru, says batteries need to be balanced "every few months" so not as critical as people on here make it out to be. If you have solar it will balance the batteries once they're full, so could be everyday if you plug in all night, or whenever you're not using it.



The alternator needs to be protected, not just "they'll be full most of the time". That protection can be as simple as a longer medium gauge wire serving as a resistor to limit the current to an absolute max of 50A or so. The Li will never drop to a low voltage, so resistance to limit the current is easy.

Would it make sense to put some kind of inline switch to isolate the alternator from the house battery charging? If I'm plugged in most times or solar is topping me off, I probably don't need to be charging while I'm going down the road. Anyone ever do this?

[d23haynes57]

Originally Posted by tpc66

Would it make sense to put some kind of inline switch to isolate the alternator from the house battery charging? If I'm plugged in most times or solar is topping me off, I probably don't need to be charging while I'm going down the road. Anyone ever do this?

Auto battery relay with full override capability.
Blue Sea 7622
https://www.bluesea.com/products/762..._-_12V_DC_500A

[SafariBen]

Sure, a manual battery disconnect could be used, or any switch matched to the current capacity and fuse of the connecting wire.