I asked this question over on the whirlpool forum and got some great answers, one of which strongly recommended Victron inverter and BYD batteries. He also suggested I ask the same question here so.....
"I have a 48v stand alone system with 3.6Kw solar, 3.5 kva latronics inverter, Plasmatronics PL60 charge controller and Raylite 1380ah flooded lead acid batteries.
The batteries need replacing.
I have managed to get 13 good years from them so I am happy with that.
But now, with a budget of around AU15 – 16k, what do I do?
I have had companies tell me to throw everything away and start again with a relatively small lithium setup.
I have also been told I can integrate lithium into the current system with significantly smaller capacity.
I have been quoted on several flooded and gel packs all of which seems to be at the upper end of the available budget.
Cycle life seems to be all over the shop depending on who you are asking and each outlet will tell you that their chemistry or construction or configuration is "the only way to go".
The amount of information/misinformation is intimidating and I don't quite know who to believe so I am turning to the well experienced people here to offer there suggestions and reasoning.
The replacement of these batteries is of course, time critical as the gennie is getting a flogging at the moment.
Many thanks in advance,"