Charging system question

John Vista · 06-26-2019, 06:57 PM

I have decided to replace the four 12V house batteries with six 6V deep cell RV batteries wired in series/parallel, so that the output is 12V. I found a local store with batteries made by East Penn, around $120 ea. Each battery is rated at 230 Ah, and the wiring should result in about 690 Ah from what I have read, plus the other benefits that this changeover results in. This will give me more Ah than my current setup.

My question is related to the charging system in our 2019 Winnie Vista 35f - can anyone confirm that I can replace the batteries as described, and that the charging system will be OK with it? I figure if the batteries are wired to provide 12V to the coach, that the charging system shouldn’t notice the difference. I thought it wise to check with this forum to see if I am on track or not. Having to change out the charging system might sway this decision, big time.

Thanks to all in advance for your input. John

Kayak73 · 06-27-2019, 06:29 AM

Your inverter is also the charger. I believe someone said it is a ME-2012. If so it is an excellent charger and a manual equalize is even available. It is indeed compatible with your new deep cycle batteries. That was taken from the previous thread when an owner with a similar rig indicated the ME-2012. That inverter is a modified sine wave and it has a capable charger, very much in tune with your new battery purchase.

Now the answer to this question needs input from you...what is the model of your installed inverter? As the owner you should look this up and find it and be familiar with the inverter. They can trip a breaker etc. so go find out what your inverter/charger model is and report back and your question can be answered with more accuracy.

**creativepart** · 06-27-2019, 07:45 AM

The ME- 2012 is a Pure Sine Wave inverter/charger.

When two 6v batteries are wired in series the pair becomes one 12v battery. Your inverter charger sees the pair as one battery. So there is no issue with charging what will be 3-12v batteries wired in parallel.

You’ll need to change the charging profile from AGM to FLA in the ME-MR remote in your RV. Also you’ll need to figure out proper parallel wiring schemes for your new bank. If not wired correctly your bank won’t be properly balanced. Lastly, I strongly recommend you install a battery bank watering system.

Are you sure the stock AGMs are shot?

al1florida · 06-27-2019, 10:31 AM

Quote:

Originally Posted by creativepart

The ME- 2012 is a Pure Sine Wave inverter/charger.

When two 6v batteries are wired in series the pair becomes one 12v battery. Your inverter charger sees the pair as one battery. So there is no issue with charging what will be 3-12v batteries wired in parallel.

You’ll need to change the charging profile from AGM to FLA in the ME-MR remote in your RV. Also you’ll need to figure out proper parallel wiring schemes for your new bank. If not wired correctly your bank won’t be properly balanced. Lastly, I strongly recommend you install a battery bank watering system.

Are you sure the stock AGMs are shot?

From the details in this topic it sure sounded like there was at least one bad battery http://www.winnieowners.com/forums/f...ge-354768.html

al1florida · 06-27-2019, 10:37 AM

Quote:

Originally Posted by John Vista

I have decided to replace the four 12V house batteries with six 6V deep cell RV batteries wired in series/parallel, so that the output is 12V. I found a local store with batteries made by East Penn, around $120 ea. Each battery is rated at 230 Ah, and the wiring should result in about 690 Ah from what I have read, plus the other benefits that this changeover results in. This will give me more Ah than my current setup.

My question is related to the charging system in our 2019 Winnie Vista 35f - can anyone confirm that I can replace the batteries as described, and that the charging system will be OK with it? I figure if the batteries are wired to provide 12V to the coach, that the charging system shouldn’t notice the difference. I thought it wise to check with this forum to see if I am on track or not. Having to change out the charging system might sway this decision, big time.

Thanks to all in advance for your input. John

1st: If you haven't purchased the batteries yet, to to Sam's Club or Costco for the golf cart batteries. They are less than $100 each, usually about $90.

2nd: Once you have all 6 batteries installed, you need to re-program your inverter charger to tell it you now have 660AH of battery instead of the 400AH that the old setting probably was.

Changing the setting to either 600AH or 660Ah should provide more amps going to the batteries when charging.

**creativepart** · 06-27-2019, 10:38 AM

Quote:

Originally Posted by al1florida

From the details in this topic it sure sounded like there was at least one bad battery http://www.winnieowners.com/forums/f...ge-354768.html

I agree. I'd remove the AGMs and have them load tested before switching to 6v GC batteries.

But then I wouldn't switch to 6v batteries at all. 660aH of GC batteries yields ~ 320aH of usable amps. I'd bite the bullet and spend $2,800 for 3-LiPo batteries. I know the GC batteries only cost $720. But with maintenance requirements and the shorter lifespan that's a false savings.

**creativepart** · 06-27-2019, 10:43 AM

Here's a good diagram for balanced series/parallel wiring for 6-6v batters in a 12v RV.

al1florida · 06-27-2019, 10:44 AM

When you install your 6 batteries you will want to cable them like this picture:
http://www.marxrv.com/12volt/wiring1.gif

With one exception, since you now have 6 batteries. I would install the ground and 12V cables going to the RV to the center pair of batteries.

Cabling to the center set of batteries gives you the same cable length to the two outside batteries. This provides better balance in the current draw or charging to all batteries.

Kayak73 · 06-27-2019, 10:50 AM

I really do not have a "dog in this fight" however the manufacturer states this is a Modified Sine Wave Inverter series. Since I don't have the exact model number in the series I'll defer but here is the manufacturer's link:

https://www.magnum-dimensions.com/pr...rger-me-series

That's why the OP should post the model number.

**creativepart** · 06-27-2019, 10:52 AM

In the standard wiring diagram for WBGO's 4-12v batteries in parallel they have two positive and two negative take offs.

One positive connection in the middle of the bank goes to the inverter and the other is at the end of the bank and goes to the chassis 12v source.

The negatives are wired the same way - one neg in the middle of the bank goes directly to the inverter, the other at the opposite end goes to the chassis ground.

The solar controller is connected separately as well - but it's at the ends of bank and opposite end of the bank.

Wiring diagram for 2019 Vista LX 35F

**creativepart** · 06-27-2019, 10:54 AM

Quote:

Originally Posted by Kayak73

the manufacturer states this is a Modified Sine Wave Inverter series.

https://www.magnum-dimensions.com/pr...rger-me-series

Oops, my bad. It's the MS2012. Since all the Magnum accessories are "ME" I've gotten that stuck in my head.

https://www.magnum-dimensions.com/pr...rter-charger-0

John Vista · 06-27-2019, 12:09 PM

Thanks all for the information....very informative. Will get model # this weekend.

**creativepart** · 06-27-2019, 02:42 PM

FLA vs LiPo

https://www.youtube.com/watch?v=Rp8Hspi4BC4

al1florida · 06-27-2019, 06:30 PM

We have used lithium since Jan 2016 and I would not switch back to lead acid even if you gave me top of the line Trojan batteries.

HOWEVER, we dry camp and boondock about 50% of the nights we are traveling. Also we travel from 5 to 9 months of the year. There are times we are off the grid for 10 days to 30 days at a time or more. On our 2016 Alaska trip we were w/o elect for 4 1/2 months, except for 2 nights in a city run RV park. We also have 650 watts of solar to charge 400AH of lithium and our daily power use is from 100AH to 200AH, usually closer to 100AH.

My recommendation is: If you only dry camp for several days and then back on elect and just do this 2-4 times a year, it is really hard to justify the cost of lithium.

If you can justify the hit to your pocketbook then by all means go with lithium rather than the 6 golf cart batteries.

JoeC · 07-03-2019, 07:20 PM

I wholeheartedly agree with "creativepart". Lead-acid of any type is old school and can't compare with LiFePO4 lithium batteries. Half the weight, 50%+ more usable power and charge in 4-5 hours from 20% SOC instead of 24 hours for lead-acid and will last 2-5 times longer with little degradation of capacity. Lead-acid batteries start dying as soon as you start using them.

So ,if you are really going to use the batteries for something other than ballast, go lithium. I couldn't wait for the original batteries to die (one did in less than 3 years and the other is very degraded). I now have 300 ah of LiFePO4 battery and 400 watts of solar panel. Who needs hookups? Even with a DC only fridge I'm good for more than 2 days of total darkness and only 4 hours of generator time. 100% good with clear to partly cloudy days and about 50% on light overcast days. You'd be dead in your tracks charging 24 hours per day with lead acid batteries.

If everywhere you go has hookups, sure, take the lead acid route and keep them for ballast.

Pianotuna · 07-03-2019, 10:01 PM

That is not balanced.

Have a look here:

SmartGauge Electronics - Interconnecting multiple batteries to form one larger bank

Quote:

Originally Posted by creativepart

Here's a good diagram for balanced series/parallel wiring for 6-6v batters in a 12v RV.

Kayak73 · 07-04-2019, 06:37 AM

Quote:

Originally Posted by JoeC

Lead-acid batteries start dying as soon as you start using them.

You'd be dead in your tracks charging 24 hours per day with lead acid batteries.

If everywhere you go has hookups, sure, take the lead acid route and keep them for ballast.

This is pretty extreme. I also wish to point out that LiFeP04 batteries "start dying as soon as you start using them", normally have a longer life however.

I would not be "dead in my tracks" and I would NOT be charging 24 hrs per day. I've never been in total darkness for two days? However...if I were in total darkness for two days I would assume the Zombies had taken over and have all my weapons and ammo out for quick access - the batteries would be my last thought - kick on the generator. If it is worse than the Zombies the batteries don't matter at all.

I am also "good for two days and nights" with my FLA batteries and ZERO charging from anything running my 12vdc compressor fridge. Now after that...but if you want to talk normal I can boondock just as long as you with those expensive batteries - now and after finding a few problems and knowing how to deal with them. I dealt with them, instead of immediately assuming that dropping another $2 or $3k into an unknown issue would be helpful. I've still got a few things to do to make it better but I stand or sit ready to go boondocking with you and see who can park the longest time with no power pole. I'll stay as long as you can.

Of course LiFeP04 is desirable to reduce generator run time and boondock quietly. They are also half the weight. Both these are desirable things but not necessary things.

Sure, if you want to drop $3k my way I'll put those darned lithium jewels in my rig. Otherwise I'll use my two T-1275 ballast boxes for the next four years and be happy. I spent exactly $300 for both of them, 300AH. That included taxes, tag and title.

Yes, FLA keeps my rig low to the ground and well balanced to off set the slide on the other side

Kayak73 · 07-05-2019, 06:27 AM

I also did not question it but the stock refrigerator for the Itasca Spirit 2015 27QP is two way, LP/electric. With the LP fridge you should or could have never needed the LiFeP04, a whole lot cheaper and more efficient to just use the thing on LP. One tank of LP would run that refrigerator months.

I guess you changed it out for a 12VDC only compressor refrigerator?

jcurtisis · 07-10-2019, 11:06 AM

John, I’m no expert in this area, but the guy who does maintenance on my RV says you really don’t buy much by going with 6V batteries; rather, the best benefit is to go lithium. The posting above about lead acid vs lithium is quite eye opening and validates all I’ve been hearing about upgrading batteries for more off grid RVing: go lithium!

Kayak73 · 07-13-2019, 06:18 AM

jcurtisis,

Here's what the lead acid buys the OP, John Vista. Functional, operating 12volt power for his rig.

To get those amp hours in LiFeP04 costs $7000.00 cool green cash. He could save weight, the batteries last longer perhaps and they recharge faster.

Price point is 10:1 which makes it a financial decision for most folks. My take is pretty simple, all those saying we should dump that much cash into lithium might want to provide a long term low interest loan or even set up a freebie donation pool where the proponents and advocates of lithium just dump cash into the pool so us poor, unrefined, tasteless and misguided owners with FLA or AGM can become part of the elite group...

Let's see, he went FLA for 1/10th the cost. He can replace those 10 times before reaching the cost of lithium. Even if he abuses the batteries and they only last 4 years that's about 40 years of batteries in his rig - doing exactly what he needs. I don't believe any of the info about it being cheaper in the long run to buy lithium. It certainly is not today, it is simply spin by proponents.

Say you spent the $7k - can you get a replacement at Costco, Sam's, the local battery shop? How long will the company be in business who sold you the $7k setup? Say 10 years from now?

LiFeP04 is very desirable - just not practical for me yet. Maybe when at least two companies can post usage instructions and install instructions which agree. When RV techs won't hammer the system if it has to go in the shop, an unlikely thing since they usually kill even FLA. When the price point is perhaps 2:1 or even 4:1 I will consider it a viable solution.