Battery Updates and Charging - Solar - Inverters

Topic: Battery Updates and Charging - Solar - Inverters (Read 6272 times) previous topic - next topic

Re: Battery Updates and Charging - Solar - Inverters

Reply #100 – July 14, 2021, 02:15:07 pm

Three pictures attached.

1 - The metal bolt and bracket for holding down the batteries does keep the batteries from moving. Unfortunately, the distance from the flooring for the batteries to the top of the screw in the bracket is too large for my design of the two shelves to go in the battery compartment. The distance to the top of the screw, including the 1/2" rubber stopper used under the battery to allow for air circulation is 12".

2 - I have attached a picture of the typical battery tray that could be used, But, I won't be using it. I do like that strap and its length, so unless I can buy the strap by itself some place else, I may just buy that package with the strap and trays and just not use the trays in this project.

It's the " NOCO BT31S Group 31 Heavy-Duty Battery Tray, Black"

3 - Two of those straps per battery would work well.

For the 12V battery bank, I'm now planning on a metal 22.5" X 22.5" X 0.5" base or appropriate metal cross bars to go perpendicular to and on top of the two 0.5" thick 22.5" long metal pieces that go on the flooring of the battery bay.

It won't be practical for me to work on that project for now. So, it is back to temporarily mounting the 12 V banks into the bay adjacent to the battery compartment.

Re: Battery Updates and Charging - Solar - Inverters

Reply #101 – July 24, 2021, 04:21:43 pm

Making progress.

The best solution for installing the house batteries in the battery compartment would be a metal frame for them. That may allow up to 8 Grp. 31 to go in there. But, no time for that now. So I took inspiration from Roger and started using some heavier pressure treated wood.

I'll be installing a total of 4 batteries in that compartment. The other 5 will go in the adjacent bay. That will provide me with 3 12V banks at 1044 AH. Again, the whole idea of separate banks is so the Multiplus II can fast charge 3 batteries at a time at 40 amps every now and then. Most of the time, all 3 banks will be combined and charged at a slow rate of about 10 to 13 amps each plus whatever charging I get from a future solar setup.

Two straps per battery is good 2 ways:

1 - With just one strap the battery could pivot around the strap. Two straps minimizes the chances of pivoting.

2 - Using straps will necessitate frequently checking them. With two straps, if one is loose before I get a chance to check them, the other one may still be tightly held in place.

Re: Battery Updates and Charging - Solar - Inverters

Reply #102 – July 24, 2021, 10:26:28 pm

You could get 6 Full River DC400-6 L16 sized batteries in that box with room to spare for 1245 amp hr capacity.

Re: Battery Updates and Charging - Solar - Inverters

Reply #103 – July 25, 2021, 07:48:35 am

Quote from: Roger & Susan in Home2 – July 24, 2021, 10:26:28 pm

You could get 6 Full River DC400-6 L16 sized batteries in that box with room to spare for 1245 amp hr capacity.

Hi Roger,

The battery compartment in my U320 is limited in size. It's 23.5" X 23.5" X 24.5". I don't know, but I suppose 6 of those L16 may fit in that compartment. But, I don't know anything about the Full River batteries. The Firefly have a good track record in boating. Also, the 74 lbs of the Firefly are heavy enough. Now that I'm getting rid of the 157 lbs 8Ds, I don't want to go over 100 lbs per battery ever again.

I'm mounting the Firefly OASIS with spacing between them and underneath to facilitate cooling, as per the manufacturer. They're also about half the price of Battleborn Lithium. Only time will tell how well they work as the House batteries in the RV.

Re: Battery Updates and Charging - Solar - Inverters

Reply #104 – July 25, 2021, 02:01:45 pm

What a great thread this is for learning about the 12 volt electrics of our coaches.

I have not read every entry in this thread and wonder if weight distribution has been considered when changing the location of equipment and batteries. I weighed all four corner of my 1996 U320 and discovered that the passenger side was lighter then the driver side both front and rear. I moved two of three 8D house batteries from driver front to passenger rear. I also eliminated the chassis battery bank from the passenger rear. Three 8D AGM deep cycle batteries provide about 600 amp hours for house and 3000 CCA for starting (Cummins recommends 1800 CCA for M11). This simplifies the 12 volt wiring and has been working for me for 10 years.

I am considering Lithium batteries for house but unfortunately they provide very low CCA so I may have to revert back to house/chassis battery banks before converting to Lithium.

Re: Battery Updates and Charging - Solar - Inverters

Reply #105 – July 26, 2021, 10:35:31 am

Hi Wyatt,

I haven't looked into the specifics of the weight distribution because I'm only adding about 300 lbs of additional weight in 3 additional Firefly batteries, new inverter replacement, switches, cables and lumber for battery framing. That additional weight gets me about 370 AH more for the 12 V in the coach for a new total of 1044 AH.

The 3 old Deka Solar 8G8D were 225 AH and 157 lbs each. The 9 new Firefly Oasis are 116 AH and 74 lbs each.

Once I get this setup going and the RV fully loaded, I'll put the RV on a scale. That weighing will give me an idea of what I can do for a future 48V battery bank system.

Re: Battery Updates and Charging - Solar - Inverters

Reply #106 – July 26, 2021, 04:15:02 pm

More pictures

Re: Battery Updates and Charging - Solar - Inverters

Reply #107 – July 27, 2021, 06:23:42 pm

Installation moves into the bay.

1 - 4 x 4 framing mounted with bolts into the same support brackets that used to support the Joey bed. The mounting is such that there is no weight on the floor of the bay. All weight is on the 4 corners where there is support from the RV chassis.

2 - Four 4 x 4 cross pieces to support up to 16 of the Firefly Oasis batteries. I still have one of the 8Ds temporarily in the RV until I get delivery of the Multiplus II.

3 - Eventually, there will be a vertical piece of plywood in front of the batteries to support a future Quattro 48/10000. The Multiplus II will most likely go into the same bay where the Xantrex 2.5 is now.

The next work is the installation of 4-position switches, bus bars, shunt, power posts, fuses and battery cabling.

Re: Battery Updates and Charging - Solar - Inverters

Reply #108 – July 28, 2021, 08:26:31 pm

The new Multiplus II from Victron is still on backorder. I cancelled that order. I will use the Xantrex 2.5 with the Firefly Oasis for now.

The attached pictures show the planned wiring for the up to 4 banks, for both the 12V and Ground connections. Those 4 switches will allow me to control how well the Oasis batteries get charged and which banks are in use for the 12V and 120 Vac needs of the bus.

One change I may do to the wiring diagram is to add a second SmartShunt. That is, have a shunt for the 12V distribution ground and another shunt for the ground from the inverter/charger. The reason for this is as follows:

- A shunt dedicated to the inverter/charger may allow me to know when the absorption charge current is down to about 0.5A. Firefly recommends absorption charging at 14.4 V until the current gets down to 0.5A.

- A shunt dedicated to the ground for the 12V distribution in the coach will allow me to essentially have a record of the power needs of the 12V distribution system as I use the coach in the future. This is equivalent to having a watt-meter for that circuit, except that I may be able to get a lot more historical data with the Victron App that works alongside with their SmartShunt.

I still have to finish reading the exciting 120 page manual for the Xantrex, so I still don't know if it would be worthwhile or useful to spend money on a second shunt.

All wiring for the batteries and up to the last bus bar for the grounds and the fuses for the 12V are 4/0 quality tinned copper marine cable with ratings at 105 degrees C dry and 75 degrees C wet. For now, I plan to continue to use the existing wiring provided by FT for connecting from the House battery bank to the inverter and to the 12V distribution system.

4/0 cabling bought from Amazon, but supplied by Common Sense Marine

Re: Battery Updates and Charging - Solar - Inverters

Reply #109 – July 28, 2021, 09:32:34 pm

The Xantrex 2.5 can charge at 100A, depending on the configuration for the total amp-hours for the banks getting charged. Since the two 4-position switches shown above provide for controlling 4 battery banks, I plan to have 3 banks of 3 batteries each using the Firefly Oasis and the 4th bank using two of the old 8D batteries that used to be in the RV. That will give me a total of 1494 AH at 12V. For now, that will provide for both the DC and AC distribution for the bus.

By connecting 2 of the Deka 8Ds in parallel as a separate bank, it allows the Xantrex to charge them with 50 Amps each. For the other 3 Oasis banks, I could charge them at a maximum of 33 Amps per battery. With some solar in the future, I should have enough charge current to satisfactorily do the periodic restoration of those batteries, as recommended by Firefly.

I think this setup will work well for the following reasons:

1 - I should be able to have at least 1 AC unit running while driving for 4 or 5 hours with plenty of spare power for microwave, coffee maker, etc. Finally, no need to run the generator while on the road.

2 - At 100 Amp charging, the batteries will be fully charged relatively quickly while plugged into shore power at an RV park and ready for the next drive down the road, even if the stay is just one night. In addition, if staying at a Thousand Trails park, the electric for it should be free at some parks.

3 - Camping overnight at a Harvest Host should be very doable with all 110V and 12V needs covered.

Note the following: This setup is not as practical for boondocking for multiple days as an equivalent KW-hour 48V battery bank would be. This is because with the 12V battery bank and the Xantrex 2.5, we're limited to 1200 W of charging. The generator may be capable of putting out somewhere between 8 KW to 10 KW continuously, but at 1200 W of charging, I would need to run it for up to 15 hours to fully charge the batteries from empty. With the same 18 KW-hr worth of batteries, but set up as 48V banks and getting charged at 140 Amps from a 48/10000 Quattro, it would only take about 2.5 hours for the generator to fill them up. That is the beauty of 48V systems compared to 12V. Faster charging and more effective use of large generators.

Because of this charge current limitation for 12V battery banks and their chargers, I will try to find out the actual 12V power needs of the bus over the next year or so. Then, I could split those 18 KW-hr of batteries into an appropriately sized 12V set of banks and use the remaining batteries with a 48V bank setup along with a future installation of the 48/10000 Quattro to meet the 120 Vac needs. This would allow for more efficient use of the generator when off grid for multiple days at a time.

For boondocking: The future 48V bank charging at 140 A = 6720 watts. The 12V bank charging at 100 A = 1200 watts. So the two future banks together will be charging at about 8 KW. That number would be a good use of the 10 KW generator to bulk charge the batteries for a couple of hours early in the morning. Then, let solar finish charging with an absorption charge. Discharge starts late in the afternoon and night. Next day, rinse and repeat.

Re: Battery Updates and Charging - Solar - Inverters

Reply #110 – July 29, 2021, 01:43:01 pm

Ground wiring updated. Two SmartShunts used. One for the 12V distribution. The other for the inverter/charger path.

Re: Battery Updates and Charging - Solar - Inverters

Reply #111 – August 01, 2021, 05:43:21 pm

Tools of the trade.

- Betooll J40 Cable Cutter

- Jokari Model 10160 Cable Stripper

- Tempco Industrial TH1818 Cable Terminal Crimper

- Seekone Heat Gun SDL-2816

Re: Battery Updates and Charging - Solar - Inverters

Reply #112 – August 07, 2021, 01:24:25 pm

This is the weekend I get this done.

1 - I've decided to just have 3 batteries inside the battery compartment. That simplifies the wiring for the banks. Bank 1 will be inside the compartment. The other 3 banks in the storage bay.

2- On the back of the picture, you'll see the power post and the 350 Amp fuse. One set up for the 12V distribution from the batteries to the bus. The other for the 12V connection to the Inverter/Charger.

3 - On the right in the picture I have the ground bus bar and the two Victron SmartShunts.

Git-R-Done!

Re: Battery Updates and Charging - Solar - Inverters

Reply #113 – August 08, 2021, 01:56:44 pm

Battery bank 1 charging.

1 - I disconnected the AC in to the inverter and wired in a 20A line from the house. I set the switches in the Xantrex 2.5 as follows:

Switch 1
1 - DOWN (GEL setting, which works for AGM as well)
2, 3, 4 - Not Used
5, 6 - Both DOWN for Warm 50 to 80 degrees Farenheit setting. Not sure yet if it would make sense to set these differently.
7, 8 - UP for Load Sense Disabled. I may change this setting later.

Switch 2
1 - UP for audible alarm
2 - Not Used
3, 4 - DOWN for 30 A input
5 - DOWN
6 - UP
7, 8 - DOWN. The setting for 5, 6, 7 and 8 tell the charger that there is more than 1400 AH of batteries. This forces the charger to pump at maximum of 100 A.

2 - Three batteries for bank 1 for 348 AH. The batteries started at 12.7 V for OCV. Fully charged is around 12.9V for the Firefly OASIS.

3 - VictronSmart Shunt is reporting charging at just over 14V at about 15 A.

4 - The four 4 position switches are mounted on 1/2" plywood. I have added two hinges and a latch to the switch assembly. The hinged setup will allow me to get access to that battery compartment.

5 - In the picture showing the wiring inside the compartment, in the back, the right side of the lower fuse is connected to the 12V wiring for the Inverter/Charger, cable B4. The cable ground from the inverter is cable B10. That is connected to the system ground side of the SmartShunt. The upper fuse is for the 12V distribution to the RV. The output from that fuse will eventually be wired to cable B11. The 12V distribution ground, cable B8 will then be connected to the system ground side of the upper SmartShunt dedicated to the 12V distribution.

6 - A battery ground from each bank will go to the bus bar. That bus bar is already connected to the Battery side of both Shunts.

7 - While that bank charges, the next work is the framing for mounting the switches.

Re: Battery Updates and Charging - Solar - Inverters

Reply #114 – August 08, 2021, 03:52:19 pm

I thought the closest setting for AGM was the wet setting. I know it is with the Xantrex SW 3012

Re: Battery Updates and Charging - Solar - Inverters

Reply #115 – August 08, 2021, 05:51:14 pm

Quote from: craneman – August 08, 2021, 03:52:19 pm

I thought the closest setting for AGM was the wet setting. I know it is with the Xantrex SW 3012

I have the Xantrex 2.5. The switch 1 settings for the battery type are on pages 25 and 26 of manual. With that inverter, I can only set for either Flooded or Gel. On page 25 of manual, "Sealed batteries should be charged as gel batteries even though they may have a liquid electrolyte."

Re: Battery Updates and Charging - Solar - Inverters

Reply #116 – August 08, 2021, 05:55:07 pm

I just finished testing the 12V switch for bank 1. I had both the inverter charging bank 1 and the same bank providing 12V to the bus. So the setup seems to be working as expected.

Both Shunts are running and reporting voltage/currents. I still need to inspect what the Shunts are saying with a read of the actual currents.

Re: Battery Updates and Charging - Solar - Inverters

Reply #117 – August 08, 2021, 06:23:31 pm

I'm going to investigate mounting a thermostatically-controlled fan for that battery compartment. It's going to get hot in there when the switch panel is in the upright position. I have the temperature sensor from the Xantrex connected to the ground for one of the batteries in that compartment. I figure that out of all 4 banks, that one in there will be at the highest temperature.

Re: Battery Updates and Charging - Solar - Inverters

Reply #118 – August 09, 2021, 01:23:14 pm

Second bank of 3 Firefly installed in the bay. Charging nicely. The two 8Ds are in the bay as well but not connected yet.

Re: Battery Updates and Charging - Solar - Inverters

Reply #119 – August 10, 2021, 02:10:47 pm

Third bank of Firefly installed and fully charged. The 8Ds will be wired this weekend.

Re: Battery Updates and Charging - Solar - Inverters

Reply #120 – August 11, 2021, 04:33:08 pm

The pictures show the battery terminal connectors I had bought for the 8D cabling. Update: I threw them away. They are really bad quality. Not much copper on them. Roger is right, see his thread below. Buy one of those instead. I'll keep the picture of the one not to buy here so no one else makes that mistake.

Re: Battery Updates and Charging - Solar - Inverters

Reply #121 – August 11, 2021, 06:48:02 pm

Perhaps a better choice is military style connectors.
Amazon.com: Ampper Military Spec Battery Terminal End, Top Post Battery...

Or these, maybe longer bolts, three lugs max in any case.
Amazon.com: A-Team Performance Military Style Top Post for Dual Battery Lead...

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Battery Updates and Charging - Solar - Inverters

Reply #122 – August 11, 2021, 07:56:23 pm

Quote from: Roger & Susan in Home2 – August 11, 2021, 06:48:02 pm

Perhaps a better choice is military style connectors.
Amazon.com: Ampper Military Spec Battery Terminal End, Top Post Battery...

Or these, maybe longer bolts, three lugs max in any case.
Amazon.com: A-Team Performance Military Style Top Post for Dual Battery Lead...

Yep. Those are most definitely better quality than what I bought. Threw mine away and bought the military type that Roger recommended.

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Battery Updates and Charging - Solar - Inverters

Reply #123 – August 19, 2021, 12:22:08 pm

All set. All 4 banks installed. Last House bank and Chassis batteries charging now.

Big test next week. I plan to have 1 AC running from the 4 banks without running the generator on my first leg of a trip to FL. That first day will be a five hour drive on Wed. 8/25 from NW New Jersey to Winchester VA. I expect those batteries to handle the AC fine for those 5 hours. Two days later, two Harvest Host sites for two consecutive days in GA. Obviously, some generator help will be needed for that stay.

Refrigerator will be running on propane. While driving, the engine will warm the water. Off grid, the Aquahot will be on diesel. I'll turn the AC off if I need to make coffee, burn bread or run the microwave at a rest stop. At 2500 Watt, the Xantrex 2.5 is really only good to service 1 AC and not much more.

It was a lot of work to get to this point. I'm not happy with how a few things turned out. For example, the location and 4/0 wiring for the four 4-position switches makes it impossible to set the switch assembly vertical. No big deal. I'll change that wiring at a future time. The plan is to keep track of how much power the Chariot needs for 12V power. The SmartShunts will help to figure that out. Then, at a future time, the battery banks will be split up between 12V banks for DC needs and 48V banks for 120Vac needs. At that time, the switches will be repositioned and rewired. For now, the setup is ready for use.

I used the Flojet Maserator model 18555 000 for the first time to empty the tanks. Seventy five feet of 3/4" waste line. It worked great.

I couldn't get the Dometic to start on gas. I tried and tried, nothing. I turned on the gas burners in case it was air in the propane lines. Nothing. I tried running from 120Vac, nothing. I wasn't getting 120V to plug in the back of the refrigerator. Panel breaker was fine. Just weird. I checked both fuses from the back of the refrigerator, they were fine. I ran a direct 120 Vac line from the sticks and bricks and connected the black plug from the refrigerator to it. The refrigerator started on 120Vac. I waited 5 minutes. I switched the refrigerator from electric to gas. I heard a bang, louder than usual. It stayed running on gas. What I think may have happened is water got in there. Yesterday, I finished pressure washing the RV and I may have gotten some water in there. I tried to be careful with the pressure washer around the outside by the refrigerator, but some water may have gotten in there. But, other than messing with the electric, I don't know how water would interfere with the works for propane. But, all is well that ends well.

Git-R-Done!

Re: Battery Updates and Charging - Solar - Inverters

Reply #124 – August 20, 2021, 12:00:33 am

When did Aqua Hot switch to propane from diesel?

Affiliate Notice