So I've got a little beginner's system I put 3 x 35aH AGMs on in parallel for a total of 105ah. Panels are 200W for now, but not a factor for this question...
I can use a couple of those AGM's on another application, which would leave me one 35aH AGM. I want to upgrade the system to LiFePo4, so if I bought a nice and cheap 100aH LiFePo4 to replace the 2 AGM's, could I wire the LiFePo4 and the one remaining 35aH AGM just to get the addtional amp hours? Would the AGM drag down the LiFePo4 and ruin it?
Let's go one further: If I left the 3 AGMs inline and added the new LiFePo4 so the mix was more balanced would it have bad affects on the LiFePo4? 105ah AGM to 100ah LiFePo4?
On a sailboat, off grid mostly I have;
six fullriver 2v AGM in series for 12v
16 280ah eve cells in 4s4p with overkill 120 BMS 12v
six 330w solar on an aluminum fabricated hard top 3s2p 120v dc
two midnite solar classic 150's each 150v 100a
I programmed the MPPT controllers for the AGM's years ago to the fullriver tech's specs, they like a good two hours a day at 14.7v if possible
when I added the Lifepo4 to the system, I paralleled them using a victron lynx
with a victron battery protect on the lithium side, set to connect and disconnect the lithium to about 90% of their capacity
so approx 2kw of solar 15kw agm and 15kw of lithium all working as it should,
fulltime monitoring on a cerbo GX and quattro give me enough power for air conditioning, 5 gal domestic water heater fridge (obviously) lights tv's computers etc etc
the fullrivers are about six years old now but show no signs of degradation, after a couple of cloudy or rainy days, when the lithiums have removed themselves from the equation and the voltage is starting to drop, the cebo sends me an alert and I can either turn off the big loads and wait,
or, start the 8k genset and recharge everything.
so if you take your time and make sure your individual chemistries get the volts and amps that suits them
It's like ebony and ivory living together in perfect harmony, on pianos