Replace Keystone SolarFlex 400i with 24v system - Battery Choice?

[dcadotte]

Per the title Im looking to redo my factory Solar Flex 400i to get a bit more flexibility and still run an ac.

I have two Victron mppt one 150 | 70 and the 2nd the factory victron smart solat 100 | 30. I am planning to replace the the 12v 400W array with two 24v 250w panel arrays from Rich Solar feeding each mppt. The fist array is 9 panel( 3 strings of three in parallel). 2nd array is just two panels. Im reusing existing keystone wiring. My two Mach 15 Q have soft start but I only expect to run 1 at a time when boondocking. Factory solution had a xantrex 2000w inverter with built-in transfer switch which I'll replace it with a single Victron 24V MultiPlus-II 5kVA 120V Inverter – 95A Charger to avoid issues with power assist when running two inverters and a 15amp house cord while moochdocking. Factory solution includes victron shunt which I'll keep. ll add cerbo gx and touch 70. Ill add a single victron Orion 24v to 12 converter.

I intend to remove the two factory Dragonfly 100ah batteries but Im torn on what to use to replace them. Battleborn are just way too expensive for me. Two Epoch Elite 24v 230ah (460ah) still seems pricey given recent issues/reviews plus I can get 3 eg4 LL 24v 200ah (600ah) for only$200 more than epoch.

Looking for feedback all around as Im sure my choice of setup is a head scratcher for some and Im not ashamed to admit Im possibly overlooking something.

Thanks!

 

[HRTKD]

If you're going to run the A/C off the battery, make sure you have plenty of forced ventilation to handle the generated heat from the battery and the inverter. The Orion Tr 24-12 converter will generate a good amount of heat, so you'll have to account for that as well as the solar charge controllers. I have the Orion Tr 24-12/30 and it generates more heat than I expected.

If you plan to run the A/C very long during the day you're going to want more PV.

Do you have an onboard generator? I'm not sure how the built-in transfer switch from the Xantrex will come into play. If there's no generator then just run the shore power into the Multiplus AC-in1 and there's no need for a transfer switch at all.

The Touch 70 could be eliminated if you have an Android tablet sitting around that isn't in use.

 

[dcadotte]

If you're going to run the A/C off the battery, make sure you have plenty of forced ventilation to handle the generated heat from the battery and the inverter. The Orion Tr 24-12 converter will generate a good amount of heat, so you'll have to account for that as well as the solar charge controllers. I have the Orion Tr 24-12/30 and it generates more heat than I expected.

If you plan to run the A/C very long during the day you're going to want more PV.

Do you have an onboard generator? I'm not sure how the built-in transfer switch from the Xantrex will come into play. If there's no generator then just run the shore power into the Multiplus AC-in1 and there's no need for a transfer switch at all.

The Touch 70 could be eliminated if you have an Android tablet sitting around that isn't in use.

Thanks for the feedback and for the tips. The Xantrex will be eliminated and replaced by the single multiplus 2 which would have its own transfer switch.

As for heat, I know from past solar shed project that these converters get hot.

I agree the epoch elite battery bank might be a constraint both power or cost and why I am questioning if EG4 LL is a smarter solution.

 

[HRTKD]

I agree the epoch elite battery bank might be a constraint both power or cost and why I am questioning if EG4 LL is a smarter solution.

Size is also a consideration. How much storage space do you have to give up?

 

[justinm001]

The EG4 should have a BMS that'll integrate with the CerboGX. Not sure about the Epoch but that alone is worth the $200 and makes the shunt redundant. This will be a massive upgrade for you and a great solution. I think spending the extra few bucks on whatever is best makes the most sense. I'm not sure if EG4 is better than Epoch but I have 2x 12V EG4 400ah and the BMS fried on them both. They replaced the batteries completely under warranty which was super nice but required me to ship the entire batteries. I did notice their BMS doesn't monitor the individual cells but just 4 packs of 4 which seems odd.

BMS monitoring is amazing, my EG4's don't have them as they're older but I have SOK's in my 48V system and its so nice as they control the charge rate, voltage and monitor SoC. Also I get alerting through Cerbo if any issues with the batteries themselves.

Do you have 12V slides? This is usually the concern as they might use more power than the 24/12 converter will handle. Some run a battery inline to help with the spike.

 

[dcadotte]

Thanks for the mention on the slides. I suppose I can reuse those dragonflies for the slides. I'll look for into that as an option