End to end lead acid battereies?

[Stinsy]

I have 4 Rolls 500 batteries in series. They are 11 years old, and apart from being a bit thirsty, still do the job. J read somewhere that it is a good idea to end to end them occasionally. I never have, partly because they way a ton and not brilliantly accessible. Any ideas?
Thanks,

Mike

What are your plans to replace them?

[Sunrisemike]

Bit of a dilemma ere, was thinking about lithium, but it seems hard to get them sorted for a 24 v system. mine are basically a yachtie version that I am familiar with bigger batteries than we had on the yachts. Had gel and AGM, but that was sometime ago. Looks as if these lithiums need a load of monitoring and would cost as much as a house to replace the Rolls 20 kwh I have at the moment. What say you? I'd be interested to know the options.

Mike

[John_S]

Mike

I can't answer all your questions, but I can give a few thoughts and ask a few questions which might help you narrow down your choices.

I have been sailing most of my life, sometimes offshore racing when young and single, cruising when newly married, not much when kids were young, latterly in a family partnership where, in a Covid mistake, we bought a 15m Dutch steel trawler displacement yacht (24v system). Alas, a bit big and heavy and one of the partners wished to sell, so sold at a loss after two years. now, a small share in a day planing motor yacht.

I too looked at Lithium batteries, albeit with no urgent need to replace. I never quite got my head around whether Lithiums could cold crank enough amps to power a bow thruster and/or stern thruster and/or anchor windlass with/without main engines running. However your setup of big Rolls and small daily load looks much more manageable. TBH, three years ago, I new much less about battery management systems and balancing lithium cells etc than I do know.

Are you going to stick to 24v or go the 48v and invert to AC for everything route?

I reckoned that it would be fine to replace lead acid with lithium having ~50% of the Amp hours of the lead acid bank.

Hope this helps

John

Edit - PS, I have 2 Pylontech 5000 house batteries for 9 months now. Alos 2.1kWp solar and an EV with Octopus Intelligent Go