A typical Bosch S5 battery is lighter than an old school leisure battery. A battery does not have to be heavy to be long lasting, it is now the technology of a batteries Plate construction that is important, not it's thickness or Lead content. In fact a high Lead, heavy battery is bad on so many levels, bad for the environment in terms of lead poison; increased fuel usage pulling the extra weight; danger of back injury carrying it; etc.
Think you have lithium on the mind today
This is the way I'm going to go. More expensive I know, but if you have a 100Ah battery you can use most of the 100Ah (what is it, 50Ah on a normal 100Ah battery?), lighter and they can be charged a lot faster.
I think as a work solution that means not having to be on hook-up, the price is justified.
The two advantages most people quote is weight and usable capacity. From a 100AH battery you get 50Ah usable from lead, and 85AH from Li... Between a quarter and a third of the weight which is important for us and for EV's.
But there are other factors that I like as well. Round trip efficiency. With a lead acid battery you can only get out 85% at most of the energy you put in. With Li you get close to 100%. This is especially important for Motorhomes running on solar. That is an extra 15% usable energy on top of the 35% from moving from lead to Li.
Then there is charge speed. You can charge an Li battery much faster than a Lead battery without cooking it. And with Li it is a straight forward 2 stage charge not 3+ stages so faster on time as well.
Finally there is the number of cycles. With lead depending on who you believe you can get between 300-500 full charge/discharge cycles out of a battery. With a lithium it is counted in the 1,000's Anything from 2,000 to 5,000 are quoted. Lets pick the middle figure and just say 2500 and lets pick the best case for a lead battery of 500. This is 5 times the number of cycles... So an Li battery will last 5 times longer, so even though the up front cost of an Li battery may be higher, it provides much more utility, is more efficient and lasts a lot longer. You also gain some minor fuel efficiency from not carrying so much lead around and free up quite a bit of space.
I am loving Lithium and over the last 6-12 months it has come into my price range.
These are the ones I am looking at.
Out of stock at the moment. But four of these and use the bottom balance technique you can run them extremely safely in a motorhome as the leisure battery.
Do you have the voltage and size of the ones you linked to?
Also assume they need some kind of BMS but guess you have probably looked into this and charging?
Would love to hear your thoughts on a complete lithium solution when you have a few minutes.