Skip to main content ↑ ↓
Topic: 600 AH Lithium Battery Installation (Read 8079 times) previous topic - next topic

Re: 600 AH Lithium Battery Installation

Reply #40 –
I think you'd be fine with 1200w & 600ah.  As long as you have decent sun exposure you should be able to fully recharge every day, and possibly go for several days depending on how conservative you are with your usage.  I'm doing fine with 1065w and 400ah of BB's, and I do have a residential fridge.  I like keeping my roof a little more accessible than it would be with more panels.

Re: 600 AH Lithium Battery Installation

Reply #41 –
Our 1200 watts of solar will recharge the watts we use from our 600 amp hrs of LiFePO4 batteries on most days.  Sun angles, clouds, partial shade from trees and lots of other factors come into play in that equation. 

After a week in the Tetons on solar and battery alone with some shade every day and one all day rain we ended up about 2000 watts short of what we used.  If it had been only a partial day of rain we would have broken even.

So I am considering adding 2 more panels, maybe 600-700 watts.  That does a couple things, makes some shade and a rain day in a week easy to recover from and probably will add a few weeks on either end of the season where we are likely to get enough solar to be self powered without a generator.  How much you can get on the roof depends on panel size and arrangement and how much room you want to leave for access.  The newer 60 cell panels are shorter and can be higher power than my 300 watt panels.

We are in an RV park in Alabama now, plugged in.  We are using land line power for the residential refrigerator, run one or two diesel cycles a day on the AH, otherwise off, inverter/charger is off, my small smart charger is off.  Very little other land line use. We are cycling between 100% SOC and 90% SOC day to day. We're back to 100% before 10AM today. 

As long as your daily watts used are well within your battery capacity with enough reserve to get through a rain day you have enough.  For many with an LP refrig 400 amp hrs seems to be enough.

Make sure your max charge rate is not more than 20% of capacity for maximum battery cycle count.  This can be as high as 5000 for Battle Born batteries.  100% to 50% and back to 100% is a half cycle.  For the same use, a bigger battery set will use smaller cycles, more life and more reserve.

So far this experience has been better that I expected in every regard.

Re: 600 AH Lithium Battery Installation

Reply #42 –
We are at 1140 watts and 400ah. RV fridge. We have a 50" 4K tv and use the microwave and latte maker in the morning but never start the generator. All lighting is LED. We do shut off the inverter at night or when gone from the coach for any length of time. Even in winter, we are at float before noon. Overcast takes only a little longer. AGM batteries are going on 12 years old and still working fine.

I just removed the old Taytronics inverter and replaced it with a sine wave 1500 watt and an old Trace 1500 watt for a back up. Just turning the Taytronics on really dropped the voltage plus you could hear the hum throughout the coach. The new Chinese inverter can remain on with very little idle current. The Trace is also very good and with the setting at pulse, almost no idle current.

Our coach is 36 feet and the panels were purchased we got home from buying it in 2008. The newer panels are much more efficient and we could have 1700 watts up top with the smaller footprint of the new panels.

Usually, about 65% continuous of inverter RMS rating is the figure for maximum life.

If you frequently camp where shade reduces the output of the panels then the more the batter.

The old style inverters (heavy-transformer) will triple the start up wattage while the newer pure sine wave (weigh nothing) will double the start up wattage for a limited amount of time. I have a couple of switches so I can switch between inverters when I want to start a small compressor.

Pierce

Re: 600 AH Lithium Battery Installation

Reply #43 –
For Joe Allen's question about the steel supports.

Could they be cut to allow easy access to the space behind.  And then construct strong attachments to re-position the steel support so it could do its job.

Re: 600 AH Lithium Battery Installation

Reply #44 –
Thanks, Pierce, Roger and Bdale.  I usually use between 20 and 25% of my 300ah daily and generally fully charged up by 11:00, so It seems like 1000 to 1200 with 600AH BB should be fine.  I don't expect to be using computer, TV, micro or Instapot anymore than I do now, so the real variable will be how much more the lights (will be going to 100% led) and Foretravel internal coach systems draw over the current class C.  I'm guessing the the auto-leveling, and other internals, along with the luxury if using the propane furnace a bit more often than we do is going to be the  greatest draws.  We've been are full time and very spoiled by the solar/BBs.  :)  The biggest issue is forgetting to give the generator a run once a month or so.

Re: 600 AH Lithium Battery Installation

Reply #45 –
I just ordered two Lithionics GTX315s for ours. We had 600aH of AGM & 740w on our fifth wheel and it was just barely enough. Any shade during the winter pretty much meant the generator was coming out. I figure between the added draw of the FT and the residential fridge,  630ah of lithium should still be plenty but I'll have room to add a 3rd battery if I really want to get crazy. Hoping for 8x180w panels on the roof but we'll see... I don't want racks to elevate them above the AC/Vents and un-shaded space on the roof is at a premium with the wineguard traveler in play.

Re: 600 AH Lithium Battery Installation

Reply #46 –
Elliott,
Ours are about 1.5" above the roof, just enough to allow air and the flex electrical conduit underneath. The wattage is a maximum and rarely reached in real work conditions. The cooler the panel is, the greater the output. 36 or 48 volt panels would be great and minimize the resistance loss down to the controller. I made most of our roof mounts. Easy and the finished product is tidy. No wires visible.

Pierce

Re: 600 AH Lithium Battery Installation

Reply #47 –
Quote from: Barry & Cindy –
For Joe Allen's question about the steel supports.

Could they be cut to allow easy access to the space behind.  And then construct strong attachments to re-position the steel support so it could do its job.

In the 9l-01 coaches with a slide there is a steel truss abou 8" high that extends from the from bulkhead to the rear just under the floor and just inside the bays.  This is primary structure, don't alter it in any way.  I remove much of the fiberglass skin inside and out to allow for access.  In this space sized as it is the only way to get six batteries in there is to use the GC2 size.  Measure very carefully, it can be an expensive error if you do not.

And for forward wall of the battery space supports the fuel tank.  The back wall has all of the big 12v wiring connections on the other side.  And the inside wall supports both sides and has the AH on the other side. 

Work with the space you have.

Re: 600 AH Lithium Battery Installation

Reply #48 –
If you ever want to get your hand under the panel to attach nuts and bolts then 2" or more is helpful. Minimize the effects of shade by wiring all of the panels in parallel.  Some argue you can save a few bucks on wire costs with series wiring but that comes at a major performance degradation in partial shade.  A few bucks on wire cost is insignificant compared to the whole project.

Re: 600 AH Lithium Battery Installation

Reply #49 –
Great review. We just installed 500 amps of Battel Born ourselves. I was amazed while driving the 1800 miles, from San Jose to Nachodocious, that we did not need to turn the generator on an ounce! The engine recharged the system while driving. It charges so fast!

Re: 600 AH Lithium Battery Installation

Reply #50 –
Rodney, You do not want the alternator to be recharging your LiFePO4 batteries directly. Use a smart multi stage Battery to Battery charger from Sterling or Victron between the alternator/start battery and the Battle Born batteries.

We really like the performance of ours. Solar alone keeps our batteries charged back to 100% almost every day.

Re: 600 AH Lithium Battery Installation

Reply #51 –
Roger, Rodney has an IH45 with a 320 Amp alternator.  Would that make a difference?

Re: 600 AH Lithium Battery Installation

Reply #52 –
The size of the alternator doesn't matter much.  You get the maximum life (cycle count) out of Battle Borns if you charge them at no more than 20% of capacity so for 500 AH you want to keep the charge at or below 100 amps.  A Battery to Battery charger takes what ever the alternator puts out and uses what it wants to charge the house batteries in a multi step charge profile at whatever the max charge rate of the device is.  Victron makes a nice 30 amp B2B, Sterling makes a 60 amp B2B charger.  When the ignition is off (or engine is not running) they also act as an isolator so no other isolator is needed.  And as I understand it you can put these (of the same type and size) in parallel to get 60 amps from the Victrons for example. 

I have a 60 amp Sterling, it works well. Now that the Victrons are available I like the way they get setup and work and might have used those but more $ to get to 60 amps.

All of these can be set to any battery type so they are nice to all kinds of batteries.

Re: 600 AH Lithium Battery Installation

Reply #53 –
Another question for Roger.
The IH45 will run the second AC  (Kitchen area) off the inverter.  I only do this when going down the road and it is not too hot where I need to run more then 1 roof and dash AC's  Running numbers it looks like that roof AC is using around  111 amps from the alternator.  Is there a way this could be done without reducing the life of the batteries?

Re: 600 AH Lithium Battery Installation

Reply #54 –
I have to think on this a bit. Normally, the alternator, the house batteries and the inverter have a common connection point.  With a B2B charger putting in say 120 amps into the batteries and the inverters pulling 110 there isn't much net amps left going into the batteries.  Now if you add in solar there might be enough.

This might be a good question for Oscar (valento on the Forum) he has lots of Lithium capacity, inverters, solar, charging schemes and more from AM Solar to get an idea how they did it for him.