My lithium build

[geem]

8 CATL 280Ah cells to make my 24v bank.
JK 200 amp BMS with 2 amp active balance
Class T fuse
Victron Smart shunt.

Main part of the installation finished but still got a couple of days of wiring to finish off in the lead batteries box. We are keeping our Trojan T105 REs as back up. We will have the ability to flick a switch to shift between banks. So far so good. As an experiment I ran the 220v water maker through the lithium. We discharged at 105 amps(@24v) for 15 mins and made our normal 50 litres. All good. Also cooked dinner on the induction hob. The only issue is that we need a lot of solar to put it all back. We only have 720w but even so we harvested a record 3.9kw today through our panels.

 

[sailaboutvic]

At last you took the plung , well done you won’t regret it .
we loved our the saddest part for us was after all the money we spend and time that the new owners removed them as they like many other read stuff that wrong , ( there a fire risk)
im was plainning to build a new set on my latest boat over winter but other stuff got in the way .
what have you done about charging them ? B2B ? new alternator?

 

[Poey50]

8 CATL 280Ah cells to make my 24v bank.
JK 200 amp BMS with 2 amp active balance
Class T fuse
Victron Smart shunt.

Main part of the installation finished but still got a couple of days of wiring to finish off in the lead batteries box. We are keeping our Trojan T105 REs as back up. We will have the ability to flick a switch to shift between banks. So far so good. As an experiment I ran the 220v water maker through the lithium. We discharged at 105 amps(@24v) for 15 mins and made our normal 50 litres. All good. Also cooked dinner on the induction hob. The only issue is that we need a lot of solar to put it all back. We only have 720w but even so we harvested a record 3.9kw today through our panels.

Looks like a nice job!

 

[vas]

8 CATL 280Ah cells to make my 24v bank.
JK 200 amp BMS with 2 amp active balance
Class T fuse
Victron Smart shunt.

Main part of the installation finished but still got a couple of days of wiring to finish off in the lead batteries box. We are keeping our Trojan T105 REs as back up. We will have the ability to flick a switch to shift between banks. So far so good. As an experiment I ran the 220v water maker through the lithium. We discharged at 105 amps(@24v) for 15 mins and made our normal 50 litres. All good. Also cooked dinner on the induction hob. The only issue is that we need a lot of solar to put it all back. We only have 720w but even so we harvested a record 3.9kw today through our panels.

nice, clean and tidy install, as others said, you wont regret it.
Indeed you harvest more as it doesn't waste hours at lower current absorption, that's one of the nice things of lifepo4. The other obvs is the lack of voltage drop when discharging at 80-100A, and you'll note that you draw slightly less Amps with the watermaker as the V is higher

Are you planning for a "lid" all these unprotected terminals need a cover!

V.

 

[geem]

nice, clean and tidy install, as others said, you wont regret it.
Indeed you harvest more as it doesn't waste hours at lower current absorption, that's one of the nice things of lifepo4. The other obvs is the lack of voltage drop when discharging at 80-100A, and you'll note that you draw slightly less Amps with the watermaker as the V is higher

Are you planning for a "lid" all these unprotected terminals need a cover!

V.

The battery box is dedicated to the lithium battery. The compartment the battery is in is a sub- division of my original battery box that was huge. The whole battery box has 10mm perspex lids as standard. This section has its own perspex lid so nothing will touch the terminals. Photo below with perspexlid in place

 

[geem]

At last you took the plung , well done you won’t regret it .
we loved our the saddest part for us was after all the money we spend and time that the new owners removed them as they like many other read stuff that wrong , ( there a fire risk)
im was plainning to build a new set on my latest boat over winter but other stuff got in the way .
what have you done about charging them ? B2B ? new alternator?

We charge the lithium from the solar and and the wind generator. They are also charged via a victron B2B off the engine battery when the engine is running. We charge the Trojans froma B2B off the lithium and another B2B keeps the generator battery on float.
We can also charge the lithium from the generator and charger.

 

[Trident]

With the solar set to a lithium setting you will find record harvests as of course you don't need any absorb cycle where power is being "wasted" for hours. Very interesting that the water maker you have always talked about under generator will work happily on the inverter and make the same rate. How big is the inverter / how much power does the AC pump use?

 

[geem]

With the solar set to a lithium setting you will find record harvests as of course you don't need any absorb cycle where power is being "wasted" for hours. Very interesting that the water maker you have always talked about under generator will work happily on the inverter and make the same rate. How big is the inverter / how much power does the AC pump use?

The inverter is a 3000w low frequency inverter. The watermaker HP pump is connected to a 1.5kw motor. In addition we have a 250w/220v boost pump.
A friend is just installing twice as much lithium capacity on his catamaran as we have. He also has a lot more solar. He was going to install a 12v watermaker but I think I have persuaded him to go the 220v route.
I don't think the absorption period is the biggest factor in how much we can harvest. Its having the battery capacity to actually store the harvested solar power. When we just have lead batteries, we start the day at about 80% full batteries. Unless you have battery capacity you have nowhere to put the harvested solar amps. We tended not to run the lead batteries down. We cook on gas and make water on the generator so the lead doesn't do much.
We now have the option when battery capacity is there with the lithium to use the electric kettle, induction hob and watermaker.
I have other modification to complete such as my high output alternator (155amp@24v) and 100amp @24v charging from the generator. That might be the game changer for us

 

[vas]

with 600W solar, a few hours motoring every 4-5days and 80A watermaker (1500+W) last year I run the generator for 3h in total in over a month onboard. If I had 1kW solar, I'd rip it off completely

 

[Trident]

Interesting; I have one water maker already but am planning to put in a second, as getting caught out say mid pacific with a parts failure could be uncomfortable. An AC unit with high capacity like you have may be a very good option through the inverter - being able to produce a lot of water on days when we're seeing lots of surplus sun or even when running the engines for some reason (2X 125ah alternators) rather than having to do some every day to keep up is quite appealing .

 

[geem]

Interesting; I have one water maker already but am planning to put in a second, as getting caught out say mid pacific with a parts failure could be uncomfortable. An AC unit with high capacity like you have may be a very good option through the inverter - being able to produce a lot of water on days when we're seeing lots of surplus sun or even when running the engines for some reason (2X 125ah alternators) rather than having to do some every day to keep up is quite appealing .

Build your own watermaker. It's really not hard. I can end you details of our build if you want

 

[gregcope]

@geem do you have 12V loads? If so how do you power those?

I think you are discovering the same as me that of all the advantages (cycle life, volume, weight, C rating) the one that has surprised me is yield. FLA throws away allot of amps when nearly full where as LifePo4 just accepts it. Ergo you get allot more charge.

 

[geem]

@geem do you have 12V loads? If so how do you power those?

I think you are discovering the same as me that of all the advantages (cycle life, volume, weight, C rating) the one that has surprised me is yield. FLA throws away allot of amps when nearly full where as LifePo4 just accepts it. Ergo you get allot more charge.

We have lots of different 12v loads. 2 vhfs, Raymarine seatalk, charging sockets, pizo on cooker, etc. We use several different 24v to 12v droppers so we have redundancy.

Not convinced yet on cycle life. Several friends got 8 years out of Trojans living aboard. Weight is a none issue for us. We still have the Trojans. Yes, we wasted a lot of amps using lead. We have gone from circa 2.2kwh to 3.9kwh so we have 1.7kwh to do something else with. Boil the kettle, make water, cook the dinner are all possibilities but not all of them can be done. We still need to put it back.
We will feel our way along and see what works best for us. The funny thing is we have gone from a system where everything worked great. We cooked on gas, made water with the generator and hot water on the solar. Now we need to come up with a new procedure

 

[geem]

Now I have my lithium build complete I have added up the costs.
Firstly, my installation is a little more complicated than most as I am running my Trojan bank as well as back up (for now). This added the cost of an additional Victron B2B to keep them charged. So an extra £219. I will discount that from my costs so it is more typical of most people's build. Do consider though that some lead capacity as a back up is useful should a major failure of the BMS occur leaving you with no domestic bank.
The total build cost was therefore £1880. £994 of this was the cells. They are good quality CATL cells. We have 8 cells giving us a 560Ah bank in 12v money. Our boat is 24v so the pack is configured as a 280Ah bank at 24v. This includes the cost of shipping of cells from the USA. That worked out surprisingly cheap although a little complicated until a sussed out a way. The BMS and one B2B to charge the cells from the engine battery came from the UK with my wife so no shipping cost. As did the class T fuse. The Victron smart shunt was purchased in St Martin. Lots of bits of cable, heat shrink, threaded rod for the pack, 1"nylon sheet for compression, etc, was also purchased in St Martin. The bench top power supply came from the States so a bit of shipping for that in the costs.
Hope this helps anybody else considering a build

 

[gregcope]

@geem I wonder where you and others will take the increased usable capacity over time. I would assume less generator run times and some people might forgo a generator if they can up their solar yield/install. Alternatively as you mention there will be more Amp/hrs for induction cooking.

Can you easily fit more solar? Ontop a sparyhood/bimini? On an arch? on decks? On guardrails. I assume you have quite a bit already (think you have mentioned it somewhere). Would you consider more?

 

[geem]

@geem I wonder where you and others will take the increased usable capacity over time. I would assume less generator run times and some people might forgo a generator if they can up their solar yield/install. Alternatively as you mention there will be more Amp/hrs for induction cooking.

Can you easily fit more solar? Ontop a sparyhood/bimini? On an arch? on decks? On guardrails. I assume you have quite a bit already (think you have mentioned it somewhere). Would you consider more?

We have 720w. These are 4x180w panels on the guardrails. Two each side. I have realised recently after doing some electrical work on a couple of catamarans here in Antigua how energy efficient the tiltable solar on the guardwires can be compared to horizontal panels. I don't have space for a solar arch and to be honest, I hate the look of them. We will stick to our 720w. We may upgrade the panels at some point but that's not on the shopping list for now.

 

[gregcope]

We have 720w. These are 4x180w panels on the guardrails. Two each side. I have realised recently after doing some electrical work on a couple of catamarans here in Antigua how energy efficient the tiltable solar on the guardwires can be compared to horizontal panels. I don't have space for a solar arch and to be honest, I hate the look of them. We will stick to our 720w. We may upgrade the panels at some point but that's not on the shopping list for now.

I understand the resistance to Arches. I think they look okay on Boreals or Ovni. Otherwise they can seem a bit OTT.
We have two 110W guardrail mounted panels (one each side). 110W on deck (two 55W strips) and had a Semi-flexible 110W on the sprayhood. The sprayhood one failed after repeated removing/replacing. In retrospect we did not need to remove it. It handled a F7/F8 with ease. Looking at Sprayhood Mk2 with Semi-flexible 150/200W in either on panel or two side by side (two would be less impacted by shading).

 

[geem]

I understand the resistance to Arches. I think they look okay on Boreals or Ovni. Otherwise they can seem a bit OTT.
We have two 110W guardrail mounted panels (one each side). 110W on deck (two 55W strips) and had a Semi-flexible 110W on the sprayhood. The sprayhood one failed after repeated removing/replacing. In retrospect we did not need to remove it. It handled a F7/F8 with ease. Looking at Sprayhood Mk2 with Semi-flexible 150/200W in either on panel or two side by side (two would be less impacted by shading).

I am a flexible panel sceptic. Had two sets of flexi panels and both bit the dust very quickly. They both had poor output compared to cheap framed panels. If anybody knows a good reasonable cost flexible panel of about 100w or so I could add a couple to the sprayhood.

 

[lustyd]

I am a flexible panel sceptic. Had two sets of flexi panels and both bit the dust very quickly. They both had poor output compared to cheap framed panels. If anybody knows a good reasonable cost flexible panel of about 100w or so I could add a couple to the sprayhood.

Any ETFE panel will be good. It's likely your bad ones were prior to the switch to ETFE and so would have been less efficient and failed quickly. ETFE sorts this out entirely. I have and recommend the Renogy 100W ones, I often see 105W from each in UK sunshine and they're extremely resilient.

I don't have space for a solar arch and to be honest, I hate the look of them

If you think of it as a solar arch I agree. Call it a solid bimini though and it looks less like a massive spoiler on a fiesta 1.2i and more like a useful feature to keep the sun off, collect rain etc.

 

[gregcope]

Mine was an ETFE panel. Output was good when working. I think it failed internally due to flexing. I used to removed it after each sail. I am prepared to try again but I will fix them.

My guardrail ones are framed. The deck ones are fixed semi-flexible.