Upgrading House Batteries to Lithium

[AJMike]

Originally Posted by creativepart

The reason is your Charger is charging so your solar isn't needed. The solar charge controller sees the voltage coming from your Dc to Dc Charger.

Turn off the DC to DC charger and the Solar charger will go to work. But as I said previously - once ANY charger starts charging your batteries the Solar Charger sees the voltage and scales WAY back.

If I am interpreting what I am seeing correctly that is the opposite of what I am seeing.

When my batteries are down, say at 70 or 80%, and the charger is running when the sun is out, what I seem to see is that the charger output decreases and the solar output is high. That is, the Trends display on my Victron smartphone app shows a lower output than it is rated at and the solar charger display seems to correspond to what I see on that app display. For example:

Early morning. No noticeable sun. Charger running. Victron app shows 20 amps (rated output of charger).

Later morning. Sun out. Charger running. Victron app shows 15 amps. Solar shows 5 amps.

Near noon. Sun bright. Charger running. Victron app shows 12 amps. Solar shows 15 amps. Difference perhaps compressor fridge.

When the battery reaches 100% the solar display goes to 0, but it is not 0 until the battery gets to 100% (or near enough to not matter).

The charger output seems to be decreasing while the solar is high. The question then becomes whether seeing an output display on the solar controller means that is actually being applied to the battery.

[DavidM]

Yes, the opposite can occur from what creativepart indicated. It all depends on the voltage settings in charging parameters of the two sources of charge. In most cases with two separate charging sources, as the batteries get more fully charged (and here I am speaking about FLA batteries as I am less familiar with lithiums) one charging source will dominate and essentially turn off the other. But when the batteries are low they both will contribute

David

[Winterbagoal]

Does anyone know how, exactly, in layman's terms, the Zamp CC and the other charging hardware know whether or not to send charging current to the batteries? How are priorities decided? Does it sense/measure internal resistance to charge current and as it increases, the current sent decreases? Does it *ping* the battery with a brief micro-draw to see what current is sent back in response? Does it use the equivalent of a DVM to measure available voltage? How do these things decide to charge, or not to charge?
Do we need a charge controller/electronics/electrical engineer to answer this question?

[AJMike]

Originally Posted by DavidM

Yes, the opposite can occur from what creativepart indicated. It all depends on the voltage settings in charging parameters of the two sources of charge. In most cases with two separate charging sources, as the batteries get more fully charged (and here I am speaking about FLA batteries as I am less familiar with lithiums) one charging source will dominate and essentially turn off the other. But when the batteries are low they both will contribute

I have both the Renogy 20 amp and 40 amp chargers and both act exactly the same way. I never really see more than the rated amps going to the battery, regardless of the status of the battery (that is, how charged it is, or how charged it is not) and the amount of solar.

If what you are saying is correct (and I have no reason to doubt it) it leaves me with a couple of questions.

1) How does the charger even know how much solar is being produced and applied to the battery? If it decreases based on the solar power, how does it know?

2) The major question would seem to be of what use is the charger if it is only going to decrease its output as the solar increases? Sure. It will charge the battery if I am driving at night, or on a heavily overcast day, but for normal usage it is redundant since its output just drops as the solar increases. It seems like a waste of money.

3) And how is the dominant power source determined? Can it be changed? If so, how?

[creativepart]

Originally Posted by AJMike

Early morning. No noticeable sun. Charger running. Victron app shows 20 amps (rated output of charger).

Mike, you must be getting huge amounts of power during the night then.

Perhaps you're reading or interpreting the History display incorrectly?

[creativepart]

Originally Posted by AJMike

3) And how is the dominant power source determined? Can it be changed? If so, how?

It's not so much a question of "dominant" but battery voltage. The more voltage your solar controller sees on the house batteries the more it cuts back on attempting to charge them. Because... it thinks they are at or near full charge. The Victorn Solar Charger is a smart charger.

YOU could determine the "dominant" source by turning off any other charger.

Which is essentially what you do when you boondock/dry camp.

Unless you are paying for electricity then all that matters is that the batteries are charged up and ready to provide all the power you need. It shouldn't matter WHERE the charging came from.

[AJMike]

Originally Posted by creativepart

Mike, you must be getting huge amounts of power during the night then.

I don't understand the comment.

Dry camping, with no input to the batteries. In the morning they are perhaps at 70% when we start driving. There is little or no noticeable sun and no solar power. The charger is on and giving its rated output of 20 amps. Given that I don't understand what you are suggesting. Perhaps I am missing something?

Originally Posted by creativepart

Perhaps you're reading or interpreting the History display incorrectly?

Anything is possible, but it is pretty hard to misinterpret the Trends graph on the smartphone app, or the solar display on the Zamp controller.

I see a charging rate of perhaps 20 amps early in the morning. There is no solar input so all of that 20 amps must be coming from the charger. What else could it be?

I have the Trends display set to Charging Current and State of Charge.

[AJMike]

Originally Posted by creativepart

It's not so much a question of "dominant" but battery voltage. The more voltage your solar controller sees on the house batteries the more it cuts back on attempting to charge them. Because... it thinks they are at or near full charge. The Victorn Solar Charger is a smart charger.

YOU could determine the "dominant" source by turning off any other charger.

Which is essentially what you do when you boondock/dry camp.

Unless you are paying for electricity then all that matters is that the batteries are charged up and ready to provide all the power you need. It shouldn't matter WHERE the charging came from.

The solar controller is the OEM one from Zamp, not a Victron controller. It (the Zamp controller) does not dial back the solar input until the batteries are essentially at 100%, so at 98% I still see perhaps 15-17 amps of solar displayed on the Zamp lcd screen. I assume all of that actually gets to the batteries but, of course, I do not know that to be the case.

What I do see is a constant drop in the input to the batteries as seen by the Victron battery monitor while the solar display shows a high amount of solar power being produced by the solar panels. Assuming both displays to be correct and assuming that the solar power is getting to the battery the only explanation seems to be that the DC-DC charger is lowering its output as the solar increases. If that is actually what is happening I just wonder how it (the DC-DC charger) knows that is going on with the solar.

Renogy, who makes the charger, is no help since you can't really get any information from their support folks. I called their help line right after they opened and was told that I was number 54 in the queue, so I just hung up. I sent an email to their support folks, but they are even less help. The last time I asked for help it took them 3 weeks to get back to me, and still did not get an answer to my question.

I was going to get a Victron charger but they are all out of stock and the last estimate I got for delivery was sometime in October, maybe, so I am trying to get on with the Renogy charger.

[jcurtisis]

Originally Posted by TheArthurs

Ah, great summary!! Thanks...i am going to be getting a bundled system through battleborn and I believe it includes something like what you describe as option 2 (BIM??what does this stand for?). But just to be sure, I am going to ask them specifically if they have something to protect my RV alternator.

Just called Jessie at Battle Born Batteries ((855) 292-2831) and asked about the engine alternator issue. He said I should have been told to measure the alternator current charging the batteries to determine if a DC/DC isolator is needed. If 120 amps or more then an isolator is needed. Why wasn’t that mentioned when I called them the first two times? 😒. I was offered a discount on a DC/DC isolator if it is needed (as I wasn’t told this the first time).
Soooo...now I need to figure out how to measure the alternator current going to the battery when the engine is running.
Suggestions?

[AJMike]

Originally Posted by jcurtisis

Just called Jessie at Battle Born Batteries ((855) 292-2831) and asked about the engine alternator issue. He said I should have been told to measure the alternator current charging the batteries to determine if a DC/DC isolator is needed. If 120 amps or more then an isolator is needed. Why wasn’t that mentioned when I called them the first two times? 😒. I was offered a discount on a DC/DC isolator if it is needed (as I wasn’t told this the first time).
Soooo...now I need to figure out how to measure the alternator current going to the battery when the engine is running.
Suggestions?

I can't speak for them but I assume they want to know the capacity of your alternator. I checked with Ford (who made the chassis for my Winnie Fuse) and they told me 210 amps was the rated capacity of the alternator. I told BB and they told me to get a DC-DC charger and to not use a BIM.

Personally I have come to believe that different people at BB will give you different advice, even for the same equipment. Lichtsinn's service department told me that they would install the Winnie Lithium package and that includes a BIM that BB told me to not use.

[JLUSoCal]

Originally Posted by jcurtisis

Just called Jessie at Battle Born Batteries ((855) 292-2831) and asked about the engine alternator issue. He said I should have been told to measure the alternator current charging the batteries to determine if a DC/DC isolator is needed. If 120 amps or more then an isolator is needed. Why wasn’t that mentioned when I called them the first two times? 😒. I was offered a discount on a DC/DC isolator if it is needed (as I wasn’t told this the first time).
Soooo...now I need to figure out how to measure the alternator current going to the battery when the engine is running.
Suggestions?

I'm in the process of putting in a 40 amp MPPT to charge my Lithium and debated as to whether the alternator on my 2016 F53 chassis needed some changes.

The few times I had the batteries down (Lion Energy 105ah x 2) the alternator hit 50 amps at idle. I'm not sure above idle what it hits but I get a faster charge with the engine on then I do with my 55amp converter from Progressive Industries. I'm guessing it's the length and gauge of wire but I stopped worrying for now. I'll ask my wife to look next time we're on the highway with low batteries to see how high the amps go. Or I guess I can just rev the RPMs in the driveway - just the meter is midway !

I'm hoping my 360 watts of solar can hold me over on my long weekend trips of dry camping, if not I'll start the generator that I have to exercise once a month anyhow. I've made the mistake of not exercising the Genset in my last motorhome and always had a tough time getting it started. Was about to replace the carb when I sold it for the unit I have now.

[JLUSoCal]

"Soooo...now I need to figure out how to measure the alternator current going to the battery when the engine is running.
Suggestions?"

I put this in and it works great - https://www.amazon.com/AiLi-Voltmete...430080&sr=8-45

[BobC]

The easiest way is a digital multimeter with a clamp-on ammeter probe that reads DC amps. But make sure it goes high enough. There are some relatively inexpensive ones and they're very useful for many other applications on your RV and at home.

Amazon has a lot of options but they don't always give full specs so you might have to Google for the user manual for details. Here's one that will handle up to 600 amps AC/DC for $46:

https://www.amazon.com/KAIWEETS-Mult...xpY2s9dHJ1ZQ==

[creativepart]

Originally Posted by AJMike

I don't understand the comment.

Sorry, Lame attempt at a joke. You had said, and I quoted, that with no sun apparent you were seeing 20-amps of charging and I thought you meant from the panels. Not the charger.

I also forgot that you still have the Zamp Controller. I "thought" when you upgraded everything that you also upgraded that to a Victron.

Sorry, I'd claim it was a Senior Moment, but at my age they are all "Senior" and are just regular moments. Kind of like Mexican Food in Mexico, or French Food in France.

[AJMike]

Originally Posted by creativepart

I also forgot that you still have the Zamp Controller. I "thought" when you upgraded everything that you also upgraded that to a Victron.

No. We have the Victron battery monitor and the Renogy DC-DC charger for the BB batteries. All the other stuff is original Winnie equipment.

We ended up driving through San Antonio directly since we got there on a Saturday afternoon and traffic was relatively light. Are they ever going to finish all of that construction on I-10?

Also noticed that you have not avoided all of this heat. We were at 113 F when we got back to Phoenix but it was also pretty hot in western Texas and around San Antonio. Although we did find out that the AC in our Fuse works and that fortunately the noise does not make it all the way back to the bedroom slide.

[creativepart]

Originally Posted by AJMike

Are they ever going to finish all of that construction on I-10?

I think it's scheduled to be done the day before they tear it up to start redoing it all over again.

If you think I-10 is bad it's good you didn't attempt to go directly through town on Hwy 281. It's Houston-level torn up.

[Winterbagoal]

Feb 2019 we bypassed San Antonio, bailed onto 46 at Seguin and picked up I-10 again at Boerne. Turned out it took longer then if we'd just stayed on I-10.

[AJMike]

Originally Posted by Winterbagoal

Feb 2019 we bypassed San Antonio, bailed onto 46 at Seguin and picked up I-10 again at Boerne. Turned out it took longer then if we'd just stayed on I-10.

Interesting. That is pretty much the way we were planning to get around San Antonio, although we were going to Kerrville to get back to I-10, not Boerne. I guess I am glad we ended up going through San Antonio itself instead.

[Winterbagoal]

Originally Posted by AJMike

Interesting. That is pretty much the way we were planning to get around San Antonio, although we were going to Kerrville to get back to I-10, not Boerne. I guess I am glad we ended up going through San Antonio itself instead.

We bypassed on our way out to Yuma, and went through San Antonio on the way back. The return leg took half the time, even with the construction and traffic.
It was a nice drive, though. Got to see a different version of Texas. Spring Branch is (almost) along that route. Is that hill country up there? Our drive was hilly, iirc.
I would add that Texas interstate rest areas are some of the best we've seen, and many have RV dump stations. Sonora eastbound has one. We've used it.

[AJMike]

Originally Posted by Winterbagoal

We bypassed on our way out to Yuma, and went through San Antonio on the way back. The return leg took half the time, even with the construction and traffic.
It was a nice drive, though. Got to see a different version of Texas. Spring Branch is (almost) along that route. Is that hill country up there? Our drive was hilly, iirc.
I would add that Texas interstate rest areas are some of the best we've seen, and many have RV dump stations. Sonora eastbound has one. We've used it.

We make the drive from the Phoenix area to San Antonio, and sometimes to South Padre Island, once or twice a year and I always like the drive. But I have to say that we always seem to run into strong winds between El Paso and Junction and they always seem to be head winds or cross winds, and sometimes they are very, very strong.

It also seems odd to me that half of the diesel stops we make in Texas are B20 stations and that almost always gives us terrible mileage. Perhaps that is the B20 diesel or perhaps that is the headwinds, but our normal 18-19 mpg drops to about 14-15 mpg. Of course the cost of the diesel is also very low. We saw $1.84 on our last trip a couple of days ago.

Mostly the roads are in very good shape so Texas must be spending a lot of money on road upkeep.