Topic: Kepworth 300AH LiFePO4 Batteries (Read 627 times) previous topic - next topic

Hello folks:
I scheduled an install of the Dreiha Atmos 4.4 air conditioner unit for next week at SDG in Indiana.  In anticipation, I took out my 2 Dragonfly batteries and replaced them with two of these batteries.  Currently $978 for the pair, for 600AH!  I figured it was worth a try and so far so good. 

This is in a 2021 Wonder RL and it was a fairly easy swap to get 3 times the current in the same place.  I took the Dragonflys out and removed the two battery trays.  Then I cut off the ends of the trays, as the Kepworths are longer.  The end result was that I reinstalled the rear-most tray iback with the original screw locations, let the first battery seat itself into the tray (it is only a smidge wider).  Then I put the second battery in with only the strap, that I connected to the first battery.  There is plenty of clearance for the positive bus bar behind the batteries.

All the original cables were usable, but I needed to buy 2 new longer battery bolts (for the posts with 2 cables) and that was it.  I already had an 18" 2/0 cable to put the Victron SmartShunt back into the system.

The original Xantrex Inverter/charger is set to 14.5v as when set to 14.6, the Xantrex produces 14.69v, and I think is too close to the 14.8 HV cutoff.  Float is set to 14.3v.

When I placed a 1500 watt load on the full batteries, I saw the voltage remain at 13.24 volts while drawing 113A for 90 seconds.  Then I tried an 800 watt heater and the voltage stayed around 13.36v for this 60A draw. 

When I get my Atmos installed next week, I'll see if these batteries maintain as well with a longer draw. Reportedly, the Atmos will have an average draw of around 90A. 

Happy to answer any questions.  I've spent most of my time in the LTV FB groups for the past 3 years of LTV ownership and I am hoping this forum will be more technical posts and less selfies.

Standing by for update from RV Meca....Northern Indiana.  Light that thing up with those batteries!

All went wonderfully.  Install had no issues and we were out of the shop by 11 AM!  The high points:

In driving home, we used the AC several times, including 2 4 - hour bursts when we stopped for the evenings in the HOT midwest.  Batteries performed flawlessly and we took them down to 48% (a 303AH draw).  The Atmos 4.4 seemed to use an average of 50A per hour in the 90+ degree temps with similar humidity levels..

We left the refrigerator on Auto while driving, thus it took a lot of our Sterling BB1230 B2B output in this hot environment.  When the 3 day trip home was finished, we found our net battery status ended at 65%...a 203AH deficit.  Since the drive was about 25 hours, it appears that we needed 8A more charging as we drove to have ended up full.  Solar was impaired by clouds. 

The plan appears to be to generate another 20A of current while driving by replacing the Sterling B2B with a Victron Orion XS 12|12-50A B2B and that should give is a cushion. 

Parking in a no solar input situation with full batteries (600AH) should give us at least 12 hours of AC without having to turn on the generator.  We do make use of the Fantastic fan once the day cools.

Everyone uses power differently, but using a lot of AC, coupled with our usually long driving days seems to work with this much battery.

Found that BattleBorn finally cleared out their backorders and have the Victron Orion XS 50A B2B charger in stock.  Called them and mine should arrive Wednesday.  That should seriously increase my ability to recharge the 600AH.  I think my Sterling BB1230 barely produced any current past what was used by the refrigerator on our drive home as I think it reduced its output and most of the charging amperage I saw in the SmartShunt was from the solar.

If you make a little effort, there are BattleBorn discounts to be had.

Wow ... that is awesome run time.  How is the noise level on the Atmos ?

I never checked the decibel level of the noisy Dometic, but the Atmos was 46.6 db the one time I checked it...then later that evening, after it cooled and I turned it off, I used the same app to check the noise level of the Fantastic fan.  They were nearly identical at 46.6 and 46.5 db. 
DEFINITELY much quieter, and no hard starts as they added a SoftStart Breeze prior to install.  The fan has 4 speeds, I think, and I just put it on Auto.  Noise is NOT an issue with the Atmos.

Given the now much larger battery use with the inverted Atmos A/C, and the battery bank of 600AH, I replaced the Sterling BB1230 B2B charger with the new Orion XS 12|12 - 50.  No Sterling noise and an easy swap since the Transit has a Consumer Connection Point with a 60A fuse coming in and I added a 60A breaker between the Orion and the batteries.  LTV did installe 6 AWG wires in my 2021 WRL, so it can handle the increased charging.  I am expecting much better output from the Orion, than the constantly reduced (due to heat) Sterling.  Time will tell if I need an external fan to help push the air around, but so far, I set it at 47A input and that is netting me 46.7A output when in Bulk Charge stage

I generally have a daily use of around 35 AH on no A/C days.  When  I need to run 4 hours of AC, that amounts to another 200AH.  So 235AH is a usual day with A/C.  Leaving the Dometic on 12 volts while driving, the 50A Orion will net us around 35A for each of our driving hours.

So driving 6 hours a day (we usually drive longer) should net us 210 AH back into the batteries and hopefully the 400W of solar will keep us topped off.  In any case, we'll have a goodly reserve at the end of each day with the 600AH of Kepworths.  I think this will be a good balance.