What make do you have & wud u recommend them?
I have Valence XP 130 Ah 12v times 4, wired in series parallel to give a 260Ah 24v bank.
It is necessary to modify/change your charging system to give them the regime they require.
I treat mine very gently, they are only charged to about 85% of capacity and are not taken below 35%
under these conditions it is reckoned that the number of cycles available is many many hundreds.
LiFePO4's are very happy never being fully charged (unlike lead acids they do not suffer sulphation problems)
They also can be discharged to a lower percentage of charge than a lead acid without shortening it's life.
I bought mine second hand over a year ago but since then that batch of secondhand Valence batteries are beginning to get in short supply
(they have already gone up a bit in cost)
Would I recommend them? certainly
Would I still have changed to LiFePO4s if I had had to pay the full price ? possibly not.
My 4 batteries cost me just over a thousand squids, new batteries of approximately the same rating would cost about two and a half thousand squids ...... a bit more than an old age pension can easily stretch to
(anyway an actuary would probably tell me that at my age there is a fair chance that a set of lead acids would possibly outlast me, negating their main benefit
)
The biggest advantage I see in them for liveaboards is the ease and speed of charging, they suck power up like it's going out of style and there is none of this buggering about with trying to force the last 20% of charge into them with it taking ages and ages. LiFePO4's just suck it up until they are virtually done.
If you do only partly charge them..... they care not like mad, unlike the problems you get with Pb constantly part charging.
The only downside in my book is the one off cost of an installation