Are lithium leisure batteries worth it now?

Some reading:

https://www.t6forum.com/threads/lithium-lifepo4-12v-batteries-time-for-an-upgrade.11157/

We have a lithium system in our van and it’s been great. You can run them much deeper without issue

Thanks not sure why I didn't check on vwt4/5/6forum!

Just trying to fit one to our Movano for the same reason - dead old leisure batteries.

Thread hijack: Trying to hook up a Renology DC to DC charge controller. Anyone happen to know what is the best fuse to use for the D+ signal wire? What colour wires feed that fuse?”

Oh ok. I've not got a dc-dc charger, only vehicle to leisure via voltage sensitive relay. Should I get one if I go lion?

<p style="text-align: right;">I didn’t do the research, my husband did, but he said the battery info told him he needed to get the different charger. We’ve got the  renogy 40 amp one, because it was cheap and would do the job! You can get others that have phone connection thingies so you can see the charge and stuff. But this one is on offer and we’re skint so:</p>
https://uk.renogy.com/12v-40a-dc-to-dc-on-board-battery-charger/?Rng_ads=786795c4debd115f&gclid=CjwKCAjw_uGmBhBREiwAeOfsdwT9UA131LdoUkoUYcPey2KmKoV2Y-PbmPU_VuFWfFP_9bpRlLfFgBoCG_4QAvD_BwE

I had discounted Lithium a couple of years ago. Equivalent power output (I know they are better for other reasons) was not far off £1k which was out of my price range and we are seldom off grid for more than about 24 hours anyway. The above price surprised and it looks like they are only about £100 - £150 more than a good quality lead acid battery. Just checking if my CTEK 250SE is lithium compatible then may take the plunge.

As above - when I replaced my 4x110ah lead batteries 3 years ago, lead won quite easily. The table seems to have turned now and lithium from the likes of renology / eco-worthy / frog star drift make a very compelling case. 80% depth of discharge vs Leads 50%, the higher absorption rate should increase efficiency of the installed solar array and promises a longer cycle life to boot.

Over their life the new generation lithium work out fairly good value (if claims are close to reality).

The Renology MPPT/Batt2Batt charger looks like a good interface between solar / alternator /shore power / starter batteries / domestic bank and help make them closer to a drop in replacement.  Not sure how I feel about a potential single point of failure though - will need to plan for some redundancy there, perhaps using parallel 1/2/both switching. Not worked that out yet.

Think we'll be going over to lithium when this bank of batteries dies. Plan to keep a 130ah(ish) lead battery for engine start and another for windlass so got a reserve capacity if the BMS trips so the whole boat doesn't go dark at an inconvenient time.

One question I have outstanding is that it seems to be the thing that lithium trips the BMS when it gets to around freezing. Not sure how that would work with regards being used in a Scottish winter. Some have a self heating capacity, but not sure how hard that would hammer the usage. If it's a lot I may need to then add in a wind turbine for keeping topped up during winter, which seems to be problematic for connecting lithium, to then has to go to lead and then b2b back to the lithium which feels quite inefficient.

So more planning to do, but fairly set on Lithium when the time comes to go battery shopping again.

I'd be careful going for the cheapest lithium batteries as in the Fire Service we're seeing a big increase in fires caused by the lower end kit. Expect more regulations to come in before too long.

Chestrockwell - agreed but leisure batteries noted above are LiPo4 Not lithium ion. It's lithium ion, such as found in cheap e bikes and smart phones which are of the unstoppable fire inferno. LiPo4 is different chemistry and not an explodey fireball of death

tl;dr not worth it this time, maybe next

This is my understanding after some reading and questions to eg 12v planet. I know nothing so if you know better then please correct me.

Current engine charge is +ive vehicle to +ive via voltage sensitive relay, and the  -ive just goes to chassis. It's a SLA battery. This charging setup is only a goer with SLA batteries, so no good for LiPO, and no good even for AGM or Gel. To make it work I need a DC-DC charger. My setup is what they call non-isolated, and a non-isolated DC-DC charger is a little more money (200 vs 100). So choice is pay a little more or the hassle of running a cable for the -ive, which will mean some dismantling of cab and living area.

Then there is battery management. LiPO need protecting from over charge and use at high/low temperature. The cheapest batteries do not have this build in, so you can either set that up yourself, or pay a bit more for a battery with built in management.

On the plus side, my victron mains and solar chargers support LiPO already.

So I'm looking at:

DC-DC non-isolated charger (victron: ~200)

100 ah LiPO battery with in built management (renology: ~440)

Misc cables and fuses (30)

Total of near to £700 vs drop and replace SLA battery £100

I have plans for camping in September, do not have the time to fiddle if it is problematic, and £700 is just a little too much for me right now. I will take the drop and replace option, but fit a non-isolated DC-DC over winter when I have time to do it properly, which should extend the SLA life a little, but next time my options will be greater.

I am beginning to wish we hadn't bothered swapping either. The weight saving has value to us, and I'm sure it will be great in the end, but it has taken Mr STWHannah many hours of faffage and it's still not connected up to the weird and complicated pre-existing system. Looking forward to having it all working... van now in garage having new ignition something or other installed because it kept running after you turned the key and took it out. FML.

LiFePo4 is totally worth it, imo. Fairly comparable prices over the lifespan of the battery, lighter, more usable capacity, and higher charge/discharge rates.

My setup is what they call non-isolated, and a non-isolated DC-DC charger is a little more money (200 vs 100).

Are you comparing like for like? Does one have a higher charge rate than the other? I'm surprised there's that much difference.
I don't think there'd be anything to stop you running an isolated charger non-isolated (i.e. with a common ground).

Are you comparing like for like?

Good point. Yes like for like, not much difference in price. Could I use an isolated charger? I asked 12v planet they said don't. Maybe it would work. Maybe I waste an afternoon fiddling around and then sending it back.

I bought a new battery a 2 years ago and went agm with a b2b sterling charger. It was all a bit confusing - alphabatteries were super helpful in explaining what I needed for what and what was best for my usage.

The set up is still great, lithium may be great now I dont know. I will be speaking to alphabatteries again when the time comes!

Could I use an isolated charger?

Victron staff seem happy that you could use a common ground:

https://community.victronenergy.com/questions/75538/orion-tr-smart-12-12-18-isolated-wiring-question.html