Changing house bank from AGM to Lithium on an older Outremer 55

[Na Mara]

I am also considering upgrading my electrical system so that it includes Lithium. My boat’s dc distribution system is from 1996 with recent additions for power reefing that I made. It’s a bit agricultural in the battery box but I am reasonably happy that it is safe. If you are in that position and you are going for a system with external BMS then all the action is upstream of the battery protector(s) you put on the cable(s) to those loads.

At present I am budgeting for:

Lynx distribution system including smart BMS.
At least 2 battery protectors
Cerbo GX
3kW Victron invertercharger
3.6kW isolation transformer
3x Orion 12dc 30A chargers
Balmar 100A externally regulated alternator
4x 200Ah Victron smart lithium batteries
Associated fuses and cables.

If I was doing this with batteries with built in BMS I could replace the smart BMS with a shunt and forego the battery protectors. An all AGM installation and I can ditch the Orions as well. Pricing it all up now but it is expensive go lithium and that price difference is way more than the ticket price on the batteries.

[fxykty]

Update after 6 months in Australia and 9 months living aboard.

The Quattro puts out a lot of heat when charging 100+ amps (at 12V) from AC sources, and when inverting similar amounts for extended periods. Placing the battery in the same compartment was a mistake, as it was heating up 10+ degrees C over ambient during most charging and some inverting. When the ambient temperatures are already over 25* C that’s not a good thing!

So we moved the battery, shunt, fuse, isolation switch, Cerbo and BMS to a separate compartment.



Now when charging or inverting the battery temperature barely budges from ambient - generally 1-2* C over. I’m going to reconfigure my BMS relays and add a computer fan for extraction based on battery temperature to reduce even that temperature rise.

The Quattro now has a lot more room in its compartment and I will turn it sideways and add a high volume extraction fan that will turn on when the Quattro fans turn on (is there a trigger for that, rather than using temperature?).

1KW of solar panels is plenty for our usage (200-300 Ah per day) on sunny days, but here in Tasmania with frequent cloudy days we are running a generator every 2nd or 3rd day.

We’re adding another 1.6KW of solar when we make our hard bimini, so that will help extend the IC charge regimen on cloudy days, but really, solar is not enough if it’s grey for a week, nor for when we get to higher latitudes.

We got rid of our diesel generator and now use a petrol generator to charge, as our main engines with stock alternators just don’t charge much at all. We will be upgrading our engine alternators in a couple of months to higher output alternators and serpentine belts. The plan is to use our main engines for charging when solar and wind is not enough. Hopefully we can get rid of the petrol generator too. We definitely don’t want to add back a diesel generator - two diesel engines to maintain is enough.

[hzcruiser]

Originally Posted by fxykty

Update after 6 months in Australia and 9 months living aboard.

[...]

Congrats! That's a very clean and tidy setup, well thought through and executed, by the looks of it! A lot of sweat, tears and money went into it, no doubt.

Soon you can reap the benefit and I trust you're already sleeping much better knowing your boat inside out?

[jlodolce]

I am upgrading from three 200Ah house AGMs and one AGM starter. To replace current system with three more house and one starter AGMs will cost about $3,000 for batteries and labor.

To replace with two 200Ah LFP house and one AGM starter, depending on the batteries I buy, will cost about $4,500 - $5,500 including batteries, new dockside charger, and Victron Orion 12-12 isolator/regulator, and labor. Well worth it to get triple the house bank power with not having to buy new batteries again for a long time if ever.

Any suggestions on batteries? My short list is Dakota, Mastervolt, ElectroMaax, CMPower, and Victron. I want each battery to have its own BMS with Bluetooth.

[Pete7]

Originally Posted by fxykty

So we moved the battery, shunt, fuse, isolation switch, Cerbo and BMS to a separate compartment.

Could the battery cable attached to the pos of cell 4 be moved so it doesn't lie on top of the negative terminal of another cell? just a thought.

Pete

[Philtao]

Originally Posted by jlodolce

I want each battery to have its own BMS with Bluetooth.

You may want to do some research about having lithium batteries in parallel. I recently answered a question about DIY vs. drop-in" batteries on the TAO forum (https://www.taoperf.com/forum/topic/94/) that will give you some indications of the challenges.

Victron and Mastervolt may have overcome some of these challenges by having some communication across the batteries and some cetralized management (people in the know may confirm or deny that), but it is not the same price. Also to consider that going with one of these, you will be stuck into their proprietary wheel (some of them lock access to some parameters and you must call - and pay- a certified installer to change them)

A less expensive and more flexible approach would be buy 4 x 400Ah Winston cells (or equivalent good quality cells) and assemble them in series (I heard that it is what's inside some high-end drop-in batteries - to be confirmed?). It is easier to do than connecting batteries in parallel as you do not need to be careful about having exactly the same cable length between them and same connection resistance. And buy a good BMS

[capn_billl]

Originally Posted by fxykty

We got rid of our diesel generator and now use a petrol generator to charge, . We definitely don’t want to add back a diesel generator - two diesel engines to maintain is enough.

Seriously?

I got rid of gas generator to buy a diesel as I got tired of maintaining the gas engine.

The diesel runs like a clock, just oil, and filters.

On the gas generator, spark plugs, carburetor problems, overheating, fuel problems, ethanol separating, low octane, knocking, misfire, moisture in fuel, stalls when a big load is added,....

[fxykty]

Originally Posted by capn_billl

Seriously?



I got rid of gas generator to buy a diesel as I got tired of maintaining the gas engine.



The diesel runs like a clock, just oil, and filters.



On the gas generator, spark plugs, carburetor problems, overheating, fuel problems, ethanol separating, low octane, knocking, misfire, moisture in fuel, stalls when a big load is added,....

The cheap petrol generator is a temporary solution and we’ll see how it goes. So far we’ve seen all those issues other than poor petrol. Oh well. It’s 1/20th of the cost of a new diesel generator.

The existing diesel generator was beyond reasonable service life when we decided to get rid of it. We’ll see how well new higher output alternators on the two main engines perform (and more solar) before we decide whether to replace the petrol generator with a diesel generator, or with nothing. We’ll do that in about a month.

90 hours/5 months of use of the petrol generator and it’s not too bad, but definitely more of a hassle to use than a built-in unit.

[fxykty]

Originally Posted by Pete7

Could the battery cable attached to the pos of cell 4 be moved so it doesn't lie on top of the negative terminal of another cell? just a thought.



Pete

There’s about 2cm of vertical space between the positive cable and the negative pole of the #3 cell.

[fxykty]

Our BMS has six relay outputs that we use to control charge sources and the two main cut off contactors.

Today I finally consolidated the three high voltage warning (HVW) BMS relay outputs into two: one for the salon area equipment (Quattro and 3x solar regulators) and one for the aft port engine compartment equipment (2x Balmar external regulators and a wind generator regulator). This gave me a spare relay that I’ve used for a battery temperature based extraction fan for the battery compartment.

I used a Finder 55.34.9.012.0040 relay that can output 4 independent relays in any combination of NC or NO. 12V + is fed into one side of the BMS relay and the other side feeds into one input of the Finder relay. The other input of the Finder relay gets 12V -. With the BMS relay set to NO the Finder relay gets no power when the BMS relay is not triggered. The relays to the Quattro and the three solar controllers all need only a short circuit for remote control on, so they are wired as NC in their respective Finder relay outputs. If the BMS triggers the HVW the BMS relay closes, which sends power to the Finder relay and it opens each output circuit.

This is the design for the relay outputs:



This is the implementation:

[fxykty]

We've decided to double our battery capacity to allow for more grey days and to take advantage of our 2.6KW of solar charging in good conditions. We will create a second 4S 12V 700Ah battery to match our existing one, buying the same Winston cells, and will put it in parallel with the existing battery. Thanks to Jedi for his reference diagrams, which we've used to plan and design our new system. Our system design for the current single battery and future parallel battery are attached. I've also attached our various configuration specifications for those that are interested.

This process to prepare for a future 700Ah battery in parallel with the existing battery took 5 full days from disconnecting to reconnecting, during which we had no AC power other than via extension cord from the marina dock (we made sure we were in a marina while we did this). We successfully tested our house/start battery parallel and start battery parallel so that we did have 12V DC power for almost the entire time (barring the day it took me to change over the charge and load busses). I had to reconfigure the solar controllers so that they could work without BMS control and charge the start batteries. This was a good test of how we need to operate if the LFP battery(ies) go offline for whatever reason. Since we have an electric galley and couldn't use the induction stove top we got good at using the pressure cooker and oven for all of our meals. In good weather the solar oven works very well and we have an emergency camping stove that runs on petrol.

Decommissioning

• Turning off, then disconnecting and removing all DC wiring between battery, Quattro, the three main bus bars, the shunt and main fuse
• Removing the two Gigavac contactors and the main fuse (ANL)
• Removing the AC wiring to the Quattro (AC distribution, generator feed and shore power feed)
• Removing the TAO BMS and relay distribution bars
• Removing the terminal bars to separate the 4S battery into its component cells (they're 21kg each, so much easier to handle individually)

Moved the Quattro to a separate compartment, which it shares only with the Cerbo and our stereo amplifier/subwoofer

• The Quattro had been in the main compartment that has all the bus bars and other equipment, and the battery was in the separate compartment. But the separate compartment is too small for two batteries, while it is just the right size for the Quattro. Hence, the need to swap the locations of the Quattro and the battery
• Two extraction fans turn on when the Quattro's internal fan is working - this should help mitigate the horizontal mounting position of the Quattro (not enough height in the cabinet to mount it vertically)
• Note that there is a terminal bolt holding together two pairs of terminals in a join. I will be installing an isolation switch at that location, but the switch is not available in a timely fashion. I've checked the temperature of the terminals during high current draws and there isn't any heat.

Designed layout for the main compartment wiring and equipment

• While we only have one 4S battery now, we will in 6 months install a second 4S battery and wire the two batteries in parallel
• All cabling between the batteries' main terminals to the main negative shunt and the main positive battery combiner bus must be exactly the same length
• Need room for two main fuses (T-class) and two TAO BMS 500A shunts (currently we only need one TAO shunt and its board is on the SmartShunt), plus a second TAO BMS
• Charge and load bus bars will have fused connections for all wiring
• New Blue Sea 7713 remote battery switches (replacing the Gigavac contactors) take up much more space than the contactors did

Repositioned and rewired the three solar controllers, which are in the main compartment

• Added in the main compartment double-pole breakers on the wiring from the panels to the controllers
• Repositioned the three controllers to provide wall space for the TAO BMS and relay distribution bars

Installed new and existing components

• 2x T-class fuses
• 2x RBS
• SmartShunt
• Negative bus bar remains in place (bottom left behind the battery)
• 2x Victron Energy high load 5-hole bus bars with 9x Victron Energy mega fuse holders
• Switch for parallel between the two positive bus
• Battery combiner bus (brings together the two batteries' positive feeds and connects to the two RBS)

Installed new wiring and adapted existing wiring between all components

• Borrowed hydraulic crimpers and cable cutting tools from local electrician to work with 70, 90 and 120 mm^2 wires
• Was able to re-use the old battery cables for the Quattro (2x 120mm^2 at 1.6m for both positive and negative DC)
• New cables to connect battery positive to fuse and fuse to combiner bus and battery negative to SmartShunt (made two of each in 120mm^2 - one to use now with current battery and second to use with new battery). Since the battery is now within 0.4m of the fuse/shunt we can use single 120mm^2 cables
• New cables to connect positive combiner bus to the two RBS and SmartShunt to negative bus - 70mm^2 due to very short lengths
• New cables to connect from RBS to the charge bus and load bus - 70mm^2 due to very short lengths

Installed battery in new location, with room for second battery

• Re-installed TAO BMS and relay distribution bars, plus the always-on distribution bus
• Installed a Peltier cooling module on the far side of the battery from the exhaust fans - this should provide cold air to the battery and adjacent solar controllers, which will be drawn past all the wiring and components before being pulled out by the fans

Reconnected all data and relay wiring
Yes, the small wiring is messy, but I figure since I'll be disconnecting much of it and reconnecting in parallel with the relay outputs from the second BMS in 6 months time I might as well just keep it functional. Wires are secured.

[fxykty]

We’ve got the 4 new cells (Winston Thundersky 700Ah) shipped at 3.28V volts and still the same today two months later. Connected the 4 cells in parallel today and connected the bench top power supply we bought a few months ago. Set it to 3.4V constant voltage and it’s sending 4.0A current. Getting the 2800Ah up to 3.4V will take a while! That’s OK; we’ve got 2 months before we’re in a marina and can take the boat dark and install them.

When we do the new battery install we’re going to move the three solar controllers into the inverter/charger compartment - they generate a fair bit of heat and we’d rather keep the main compartment cooler. We’ll also move the Cerbo into the battery compartment because that’s closer to where we want to install the Touch 70.

We’re using a Parallel Step-Method Top Balance:
1- Wire the cells in parallel
2- Set the power supply to 3.400V and 80% or less of the rated amperage (80% to not burn it out)
3- Turn on power supply and charge cells to 3.400V
4- When current has dropped to 0.0A at 3.400V turn off the power supply & set it to 3.500V
5- Turn on power supply and charge cells to 3.500V
6- When current has dropped to 0.0A at 3.500V turn off the power supply & set to 3.600V
7- Allow current to drop to 0.0A (or very close) at 3.60V
8- Done, pack is balanced.

[fxykty]

Installation of the second battery has begun. Boy, it's a lot more work than I expected, so I've split it into a number of stages. First two stages are complete:

1. New equipment displays at the navigation station This involved redesigning the navigation station panel that already has car stereo, vhf radio, Tao monitor and LED panel, double AC outlet, 2x double USB outlets, and a large hole where the old AIS unit's display was mounted (which was removed when we installed a headless AIS unit) so as to add a GX Touch 70 and the second BMS's monitor and LED panel, plus a Raymarine remote control unit. I took the panel out and removed all the equipment, then used cardboard templates for each piece of equipment to move around until we had a decent layout. The first photo shows what it looks like now, with all cables attached and ready to go. One constraint was to leave the stereo, VHF and AC outlets in their existing locations.
   
   
2. Move three large MPPT solar controllers out of the battery area The controllers use up a lot of wall space and put out a lot of heat, both of which aren't good ideas for a battery compartment, so I moved them to the inverter/charger compartment, which has more space. I also removed the Cerbo from that compartment, mostly because the HDMI/power cable for the Touch 70 display is very short. I added a solar charge bus to the compartment to simplify the solar controllers's power wiring - the bus requires 95mm^2 cables (orange cables in the photos) to handle the theoretical maximum charge current at 13.8V of 240A. Also installed an isolation switch on the DC positive to the Quattro and added a new 100/30 MPPT solar controller for our new 300W solar blanket and an additional fan. The fans turn on whenever the Quattro's internal fan turns on, or when one of the solar controller's high temperature warning is triggered. The second and third photos show this compartment. Note that the small bus is to parallel the Quattro and MPPT controllers' relay command wires and to control the three compartment fans.

[Baronkrak]

Originally Posted by fxykty

Installation of the second battery has begun. Boy, it's a lot more work than I expected, so I've split it into a number of stages. First two stages are complete:

And doing it in the tropics during the build up is a real challenge.

By the way, all these sensing wires need fusing.

[fxykty]

Originally Posted by Baronkrak

And doing it in the tropics during the build up is a real challenge.



By the way, all these sensing wires need fusing.

The 12V+ power to the first positive relay bus is fused at its origin (3A). That bus splits the power to the four relay NO ports of the Quattro and solar controllers, then through their common ports to the positive fan bus. The three fans are connected to the positive fan bus. The fan negatives are connected to 12V-. I’m using 14AWG wires and every individual component can take 3A or more. AFAIK that means no other fuses are needed.