[OurNewelllife]

Hey fellow Newell owners! We just purchased #637 and drove her home to Florida from Arizona. What a beauty she is however we have been having some charging issues along our 4 day adventure back to Florida. Now home we realize that yes, the the cranking batteries are new however our house batteries are toast and need to be replaced yesterday. Tom has been an amazing resource of information to us from the start and we are so thankful to him and this site.
We are trying to locate 4 AGM batteries and having some difficulty getting them fast. I did locate 4 Lifelines but they are pricey which made me begin to consider Battleborn or equivalent Lithium Iron Phosphate batteries.
Our coach has 2 ProSine 3.0 inverters and only 4 house batteries dated 11/08.  I want to make the best longer term decision knowing we will probably go with solar down the road and enjoy boon-docking.

My question is, how many BB batteries do I need for (2) 3000 watt inverters and how is the install different that standard AGM batteries?

Thank you in advance.

Brian

[Richard]

Welcome! Hope you enjoy your new toy. We will definitely get together when Rhonda and I get back to Florida in the fall. We live over in Inverness.

Ok, slow down, breathe............

The answer surrounding batteries highly depends on how you plan to use the coach. If you go pedestal to pedestal then any battery will do to keep the frig and stuff running during the day. If you plan on boondocking and running the AC while off grid then that is a whole another animal.

So can you elaborate on your planned use?

The amp hours you will need is really not a function of powering two inverters, but it is a function of how much power you will consume while off grid. Hence the question on your usage.

[bikestuff]

Brian,

To answer your question....How many BB batts do you need? It depends on Richard's question. What are you gonna do? More batts equal more time to run without generator. 4 BBs will allow you to park, watch TV for a while, run the 12V water pump for a shower and still have battery left in the morning. 6 will extend that time...8 will extend that time more and 12 will extend that time even more.

You will be limited by the available space. If you have 4 8D batteries, I suspect you will be easily able to install 8 BB batts.
They are essentially drop in replacements.

I would definitely research the battery state of charge (SOC) options for the Xantrex. Here is why....With Lead-acid batts, the voltage will drop as you use energy out of the batts. With lithiums this does not happen. They keep the voltage high until the very end. This means you will not ever know how much stored energy you have left. A state of charge system will count the amps in and subtract the amps out and tell you how much (in percent) you have left.

The BBs are 100 Amp-hour (Ah) capacity batts. So are most of the 8D AGMs and lead acid batts. This is misleading though. You can not really use more than 50% of the lead acid battery capacity without seriously degrading the battery. You can use almost all of the capacity of the lithium batts. So one BB has almost twice the capacity of a single L-A battery. AND...AND...AND... they weigh 1/3 as much.

CONS: So getting lithium batts is pretty much a no brainer? Not so fast! There are a couple of huge downsides with Lithium batts.
1). They are heckin expen$ive. Nuff said about that.
2). This is more important. Lithium batteries have very little internal resistance. This means that if they are empty they will accept as much current as you provide them. 8 batteries will consume hundreds of amps on re-charge. The inverter probably can handle this with no problem....but the alternator cannot. The alternator will put out its maximum to recharge the batts and will eventually get hot and melt down if not robust enough. The more batteries you have the more this is a problem. BB batteries do not talk to each other so if one is empty, they will all be empty and will all pull as many amps as they can. (See State of Charge above).

A good idea if boon docking is to crank the generator to charge the batteries BEFORE you crank the engine. Just cranking the engine will cause the isolator to start sending a massive amount of current to the batts. (Potentially melting the isolator too).

I know this is a lot of random thoughts (hopefully some use to you)....but the path to lithiums is paved with dead electronics.

Cheers,
bill

[folivier]

As another BB user I would have to agree with the above comments. The most important factor to consider is how will you use your coach? The same approach goes to considering solar panels. The longer you plan to be unplugged will be the deciding factor on how many batteries.
I'm somewhat surprised your coach has 2 inverters with only 4 batteries. Unless it was designed to use the engine alternator to provide power through the inverter(s) to run your air conditioners. And this would only apply while driving down the road. Most all of us use the generator to run the air conditioners and rely on the house batteries to power the fridge and other stuff.
Unless you need to replace your house batteries now I would evaluate your usage for a while. I would strongly recommend installing a Victron BMV712 or other SOC (state of charge) meter. Your inverter(s) may have one already. That will allow you to see just how many amphours you will use overnight and in a 24 hour period. I could give you a WAG but it could be high or low and could cost you more or less when buying batteries.
That being said I love my BBs and am glad I bought them for our Alaska trip last year. However, for our typical usage going forward they are somewhat overkill. Very nice for the few times we dry camp but unnecessary for typical usage where we are driving with or without the generator running if air conditioning is needed.
The biggest usage will be for your residential fridge and that will use anywhere from 100-150 amphours by itself. The other usages will be water pump, lights, radio, charging laptops & phones, fans, etc. that you will be able to control.
One thing about BB and other Lithium Iron Phosphate batteries is they are frequently called "drop in replacements" for lead acid batteries. That is true in the sense that the physical size is similar and they have a negative and positive post but they do need a different charging profile. Not difficult to do but it does take some design and thought.
None of this is to dissuade you but to help you in deciding what you want and how to do it.
Search this forum and you'll find a few discussions on installing the BBs and others. And ask questions here on the forum. There is quite a bit of knowledge here and helpful folks for you to bounce ideas off of.

[Latitude 28]

Brian,
Back in May we had an immediate need for house batteries and wanted to go with LifePo4.....still want to go Lithium but will gradually work into them all the while setting my current system with upgrades keeping that in mind. Now having said that Tom recommended Oreilly's for their AGM batteries. I purchased six of them for $396 ea. (ask for a discount). Those batteries are USA made by Deka....my local store here in Wildwood, FL had them the next morning from the Lakeland warehouse. The manager even delivered them to our house and picked up the cores....great service!

Back to the lithium, this guy on You Tube, Will Prose, (https://www.youtube.com/watch?v=E4pN4DVPOcY) has a channel on LifePo4 batteries that has helped me in understanding all the details. Glad I am waiting and gradually stepping into the LifePo4 world.

Steve

[OurNewelllife]

Thank you for the great information guys. It’s much appreciated. I decided to go with AGM as I only needed four and most likely won’t be Boondocking that much. I found company by the name of Millikan battery and electrical in Orlando. Cecil, the owner was great to deal with and his technician Eddy not only delivered them to my house but gave me a hand installing them! I tipped him well and thanked him for his time and expertise. I would highly recommend them for sure.