Combining technologies

[grizzzman]

What is CG2? I’m new to this so please forgive my ignorance. I am the OP and still working through leaving my AGMs in place when I add the Lifepo. I was of the same mind as you. Make the Lifepo primary with a charge profile to suit. I may put a battery switch in to isolate the two chemistries but is that really necessary. My cells are on order and as soon as the Lunar holiday is over maybe they will ship.

Please don't take this wrong. It would NOT be a good idea for you to combine LFP and CG2.

 

[emeraldcoastcamper]

So YES you can string them all together but depending on the battery you set the SCC to, you will either over charge one set or undercharge the other ... ALSO - with LFP we run our abtteries down to 10% with zero issues BUT if you have them strung with WET CELLS or AGM then you have to be constantly monitoring the AGMs to make sure you not below 50% ....

The way we did it until we finally got rid of our legacy systems was initially had one BANK of solar panels that fed 2 SCC through an A/B switch ... We also had a bank of LFP batteries and a Bank of GC2 also controlled to the inverter by an A/B switch ... And a battery meter with an A and B input connected to both. SO we would always charge the LFP with the LFP SCC first while having the Inverter use the GC2 batteries .. when the LFP got to 100% we would then switch it vice versa and have the GC2 charge via its on SCC and use the LFP bank to operate the inverter ...

And we found doing it that way was significantly better than stringing it all together....

Good plan. Simple and effective.

 

[emeraldcoastcamper]

If you want to run both, you'll have to isolate them with a switch so your either running the AGM's or LFP but not both. Then you have to consider the charging aspect and even with BB's you still have to be within a certain spec for them, a 2 stage charging process.

Tesla Packs are not LFP and that is even more persnickety and their voltage range has to be adjusted for. DIY is likely the better option, you can make a 200 / 300 or even 400AH 12V pack. 200AH cells can be had for as low as 71 USD ea, 4 cells = 12V plus BMS & Shipping

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Catl Lishen 3.2v Lifepo4 202ah Lithium Batteries 3.2v Lifepo4 200ah Battery For Ess,Off Grid,Home Solar Energy - Buy Catl,3.2v Lifepo4,200ah Lifepo4 Product on Alibaba.com

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EDIT: Adding switch link

e-Series - Blue Sea Systems

350 Amps continuous rating for inboard gasoline or diesel engines.

www.bluesea.com

I’m liking the Battery switch as a way to keep my agms in play yet isolate them from the new LifePo. Am I correct is saying connect positive lead from li to 1, connect AGM to 2, connect load (inverter) to Common. It just seems too simple.