Lithium upgrade

[wmcunninghamii]

I realize this topic has been beat to death but I am going to beat that carcass some more. I have done some research on the forum in an effort to answer my questions but came up empty/confused. Some of you have been through this so if you can just link me to relevant threads I would appreciate that.

I own a Freedom 30. I sail singlehanded 95% of the time. In the past I have participated in local as well as ocean racing (transpac).

Yea, yea, I know In A Freedom 30?? Well, I brought what I got to racing and I have had a blast. But as I age I am beginning to enjoy cruising locally and just hanging out at anchor.

My electrics have always been just a step behind ideal. Last year I worked with Rod at Compass Marine to upgrade my 14 YO Balmar 70A alt to one of Rod's 120 A units. You all know how that goes. Rod convinced me to upsize my alt just in case I decided to go Lipo in future. That was prescient.

My set up is as follows .

Yan 2gm20 equipped with serpentine and 120 amp alt (9 months old) which is regulated by Balmar ARS5 (14 years old). I have the Regulator derating the alt to around 70 Amp max. So I don't exceed the batt current limits and because I had been motoring a lot to get to sailing ground, I got plenty of charge that way. Not doing as much motoring nowadays.

I recently replaced 3 each 110 AH lifeline AGMs (14 years old) with three 120AH Vmax tanks AGMs (9 mos old). I knew going in the Vmax batts would very likely be less durable than the Lifelines but would hopefully last long enough to allow Lipo to drop in cost a bit more. So far the cost reduction strategy is working fivers.

Two of the AGM batts are house and one is start. My charging sources charge the house directly. The start is charged using Xantrex echo charger.

I monitor the house with Xantrex batt monitor (dedicated shunt) and with the Kidd Controller (via wiz bang - see below - interfaced to shunt) I really like this arrangement because I have two independent systems monitoring the Batts.

I have two other charge sources in addition to the alt:

2 each 100 watt panels (1 YO) into a midnight solar Kidd controller (highly configurable and about 6 years old), these panels replace some flexible panels on dodger and deck which I relied on for long races but were not that durable). The Kidd is equipped with what is called a wiz bang Jr. Which is basically a shunt interface to the controller so that the controller knows what's what with regard to charging status of the batts.

1 each Xantrex 20A shore power charger (14 Years old and limited configurability)

All charging sources are temperature sensing and compensated: alternator, regulator, batteries, Controller, shore power charger.

I also have a 14 YO Blue Seas System battery isolator switch which allows combining house and start should one system be inop. I never use this because I believe the concept of joining a bad bank with a good bank has been shown to be a very bad idea. I note Blue Seas no longer sells this switch. I will be replacing it as part of the project.

I am surely missing some bits but those are the basic components of my system.

Use case:

So as I have been doing more "cruising" which is actually more hanging out and drinking cold beer at anchor, I have added one of those small 12 Volt portable freezer/fridges and it rocks! I have an icebox but that can't keep anything frozen and I have to tell you, after 22 years of an icebox only, having the ability to keep one cubic foot of space at freezing temp is crazy cool! Unfortunately it costs me about 3 AH average depending on weather. I did not want a permanent refrig install. When I get home I pop the cooler out and hit the road. Works great in the car too. This portability probably costs me an amp or two, I realize that.

I also added a diesel heater (also cool as hell) and, during winter, that guy burns 3 AH avg depending on setting.

Also this stuff adds weight so there is power consumption AND weight to consider.

Bottom line, I have found myself having to do some at anchor engine charging from time to time. There is a lot of tidal current in my area and, the boat's orientation can be such that the arrays don't get a good sun angle. I do have single axis adjustability off the pushpit so when the sun is anywhere behind me i can get a pretty good power but if the planets aren't aligned I get some low output. I don't really have enough unshadowed deck space to solve this and I am not crazy about installing a windmill.

My objective is to be able to rest at anchor for two days (48hrs) without engine charging. I figure that will require (with margin) about 240 AH. I assume three 100A Lipos with 80% availability (10% margin hi and low) = 240 AH available power

Soooo. The plan is:

Retain the Kidd and the arrays as is - lipo configurable

Retain the alt and serpentine as is - does not care about battery type but I am aware of loading and heat issue with lipo so I'll derate appropriately probably leave as is. I have done some testing at 70 amps for a couple hours and alt runs ate around 130 - 140 F. This is at around 60% of rated alt capacity.

Replace regulator with Lipo configurable regulator

Replace shore power with lipo configurable charger

Replace all three 120 AH AGM with 100 AH Lipo. Dedicate whole 300AH bank to house

Retain batt monitoring capability but maybe upgrade the Xantrex monitor to the new agile CDI Electronics SG200 Battery Monitor which is not a technically challenging upgrade

Add new, hopefully smaller/lighter, dedicated start battery. But which battery and what chemistry and how to deal with a different chemistry from house if necessary.

And, finally, figure out how to get the start batt charged????

I don't get the concept of sending hi current charge to the start and deliver excess to the house via DV to DC charger. I feel like I should do what I am doing (and wired for) which is send the hi current directly to house and provide charge to start via some sort of echo charge or DC-DC charging. But I may be missing something important here?

My house is about 6 cable feet from the alt and the solar and about two cable feet from the shore charger. I have some (low temp) space for a start battery within 2 cable feet from the alt and six cable feet from house.

If anyone manages to read through this hot mess, I would appreciate thoughts on start battery. It will need to be somewhere in the 400 CCA range. That is 100% margin over Yanmar spec of 200 CCA. I want the margin.

Aslo, best way to get this new start batt charged. that is the biggest unknown for me.

And finally, what other protective devices might I need for batts and charge sources?

[alamoana]

I like your plan and if it were my boat,, I would increase the solar panels and add one extra similar battery. You will have 480 AH and could use 240 AH from it. Assuming it is 120 AH daily, you will need to charge that in 5 hours which is 24 amps at 14 V = 336 watts. With 2 more panels it would be enough for no engine time at all. You could even get by with no extra batteries if you start with them fully charged. Or you could just add a battery and no extra panels and they would charge during the week. LiFePO4 is great technology but will require several Upgrades to your boat and will be expensive. Good luck

[wmcunninghamii]

Originally Posted by alamoana

I like your plan and if it were my boat,, I would increase the solar panels and add one extra similar battery. You will have 480 AH and could use 240 AH from it. Assuming it is 120 AH daily, you will need to charge that in 5 hours which is 24 amps at 14 V = 336 watts. With 2 more panels it would be enough for no engine time at all. You could even get by with no extra batteries if you start with them fully charged. Or you could just add a battery and no extra panels and they would charge during the week. LiFePO4 is great technology but will require several Upgrades to your boat and will be expensive. Good luck

Thanks for the reality check. I think what you are proposing is that I expand the house to 360 ah (120 x3) with the 4th start as a separate battery or are you thinking a single house which would double as start? Would a single bank be copacetic? Seems like there might be quite a bit of spiky power happening at start but I donlt know.

With regard to "charging during the week" I am actually out for at least a week at a time so there is no real downtime during this period. I may be misunderstanding your thought. I do typically motor some miles during that time so get some engine charging that way as I mentioned, but sometimes not enough to overcome cloudy weather or non optimal boat orientation.

On panels, I just do not have the room for additional. Well, I could do it but the boat would look like a Roman phalanx or something. I do have space for potentially 100 watts on the dodger but I had one of the flexibles up there and shadowing from the sail and boom was always an issue esp. at anchor. I had thought of doing two small 50s in parallel to mitigate some of the shadowing. There may be a path forward to get an additional 75 watts in good conditions. I had been considering this as a phase 2 action though.

One of the big benefits of the conversion to Lipo is weight reduction. Although I noted that I have gone "chill" more or less, I still would like to race occasionally. It would be fantastic to offload somewhere around 130 lbs of AGM batteries which are nearly three times as heavy as AGM. The water tank and these batts are on starboard side and unbalance the boat a bit even though I try to manage storage such that this is minimized, it is difficult to do in a 30 footer.

It is absolutely true that I will have to make some significant investment in new stuff.

This was pretty much why I asked the question I did. i am trying to scope what the system would look like so that I can figure out what gear I would need and could then calculate a budget.

[Pete7]

Interesting boat, nice to be different

Your power consumption is about the same as ours with a similar sized boat.

I fitted a Victron battery widget which supplies voltage but also temperature figures for the house battery. Too high for my liking, so when we put lithium (LFP) into the boat I moved the house bank to under the saloon seats. We don't really use this space as you have to lift all the cushions each time. We opted for a 120Ah LFP drop in battery and combined that with one existing Trojan TMX 24 house battery.

With 300w of solar it provides all our daily needs in in good sunny conditions, but falls over in heavy cloud and rain when we get to day two or three. So we have the option of either shore power to the AGM start battery and then a DC>DC charger to the LFP, or use the alternator to engine battery and DC>DC to the LFP. We used the alternator twice in a 3 week cruise last year.

The lead-acid battery is there just in case the BMS shuts down whilst we are entering harbour at night and we need the chartplotter. Otherwise it just sits there on float twiddling its thumbs. Oh and will run the bilge pump when away from the boat as I isolate the LFP.

There was a fair bit of re-wiring to do all this, but worth it. Adding an inverter meant we can now boil water via a small electric kettle off the LFP, which is handy as there is a severe bottled gas shortage in the UK. Then we added a toaster, then an induction hob. Now she wants the air-fryer on the boat. We need to add another LFP battery

The good news is the speed you can charge LFP. It will take everything you can generator on an average yacht far more quickly than lead-acid. So whilst your solar will struggle to charge the last 20% of LA with more than a few amps, we can see 18A going into our LFP all the way up to full. Since the battery is now full any further solar during the day supplies the house loads keeping the fully charged LFP for the evening and night.

Here is a wiring diagram I made using PowerPoint. It may look like lots of stuff, but you have most of this already.

Pete

[wmcunninghamii]

Originally Posted by Pete7

Interesting boat, nice to be different

Your power consumption is about the same as ours with a similar sized boat.

I fitted a Victron battery widget which supplies voltage but also temperature figures for the house battery. Too high for my liking, so when we put lithium (LFP) into the boat I moved the house bank to under the saloon seats. We don't really use this space as you have to lift all the cushions each time. We opted for a 120Ah LFP drop in battery and combined that with one existing Trojan TMX 24 house battery.

With 300w of solar it provides all our daily needs in in good sunny conditions, but falls over in heavy cloud and rain when we get to day two or three. So we have the option of either shore power to the AGM start battery and then a DC>DC charger to the LFP, or use the alternator to engine battery and DC>DC to the LFP. We used the alternator twice in a 3 week cruise last year.

The lead-acid battery is there just in case the BMS shuts down whilst we are entering harbour at night and we need the chartplotter. Otherwise it just sits there on float twiddling its thumbs. Oh and will run the bilge pump when away from the boat as I isolate the LFP.

There was a fair bit of re-wiring to do all this, but worth it. Adding an inverter meant we can now boil water via a small electric kettle off the LFP, which is handy as there is a severe bottled gas shortage in the UK. Then we added a toaster, then an induction hob. Now she wants the air-fryer on the boat. We need to add another LFP battery

The good news is the speed you can charge LFP. It will take everything you can generator on an average yacht far more quickly than lead-acid. So whilst your solar will struggle to charge the last 20% of LA with more than a few amps, we can see 18A going into our LFP all the way up to full. Since the battery is now full any further solar during the day supplies the house loads keeping the fully charged LFP for the evening and night.

Here is a wiring diagram I made using PowerPoint. It may look like lots of stuff, but you have most of this already.

Pete

Wow, thank you for the detailed response. I am going to study the block and see what you have done. Will undoubtedly return with questions.

The issue of LFP BMS shutting down has popped up in my research, thanks for emphasizing that. I sail of the Cali coast, lot of night stuff and fog. I would NOT want to loose power at such times although last time I counted I had effectively twelve GPS receivers of one sort or another on the boat. I have plotter SW on two tablets and two phones (I keep old phones and dedicate them to boat related software when they retire from being phones) plus backup Garmin battery powered unit over my chart table - primary is at the helm. I think I am pretty robust with regard to BU GPS but no running lights, no instruments, no depth, no AIS transponder, no radio (do have a BU and charged handheld albeit short range). Yea, that would not be pleasant.

In terms of pwr consumption growth...same.

thanks again.

[alamoana]

Originally Posted by wmcunninghamii

Thanks for the reality check. I think what you are proposing is that I expand the house to 360 ah (120 x3) with the 4th start as a separate battery or are you thinking a single house which would double as start? Would a single bank be copacetic? Seems like there might be quite a bit of spiky power happening at start but I donlt know.

With regard to "charging during the week" I am actually out for at least a week at a time so there is no real downtime during this period. I may be misunderstanding your thought. I do typically motor some miles during that time so get some engine charging that way as I mentioned, but sometimes not enough to overcome cloudy weather or non optimal boat orientation.

On panels, I just do not have the room for additional. Well, I could do it but the boat would look like a Roman phalanx or something. I do have space for potentially 100 watts on the dodger but I had one of the flexibles up there and shadowing from the sail and boom was always an issue esp. at anchor. I had thought of doing two small 50s in parallel to mitigate some of the shadowing. There may be a path forward to get an additional 75 watts in good conditions. I had been considering this as a phase 2 action though.

One of the big benefits of the conversion to Lipo is weight reduction. Although I noted that I have gone "chill" more or less, I still would like to race occasionally. It would be fantastic to offload somewhere around 130 lbs of AGM batteries which are nearly three times as heavy as AGM. The water tank and these batts are on starboard side and unbalance the boat a bit even though I try to manage storage such that this is minimized, it is difficult to do in a 30 footer.

It is absolutely true that I will have to make some significant investment in new stuff.

This was pretty much why I asked the question I did. i am trying to scope what the system would look like so that I can figure out what gear I would need and could then calculate a budget.

I was proposing 4 x 120 AH batteries to double as house bank and starting battery. Some may say you need a separate starting battery, it is all a compromise. I would go for the 2 x 50 flexible panels plus 75 watts you could fit. I would do this as stage 1 since this is all cheap.

The weight reduction is real yet once you start with LiFePO4, all is awesome yet expensive.

Good luck

[hjohnson]

So our use case is similar to yours. We've got an Ericson 27 with old FLAs that we're finally tired of recharging daily. I'm planning to put together a thread to document our project, but the gist of it is this:

1) Build a 460AHr LiFePO4 battery out of 230AHr cells and a REC Active BMS. This will actually take up less space, and be less than half the weight of our existing 90Ahr (usable) of FLA batteries. Plus the REC BMS plays nicely with the Victron ecosystem. Cost for the cells themselves was about $800 USD, the BMS plus contactors is probably another $800 or so.

2) Upgrade our alternator to an 80A Hitachi, modified for external regulation by a Wakespeed WS500. Not as big as yours, but we just have a little 1GM10, the 80A alternator was free, and the modification and rebuild cost us $140 (Wakespeed was closer to $600). We will eventually upgrade to a Beta 14 or 16 engine, which will have a larger alternator.

3) Install a Victron Multiplus 12/2000 Inverter/charger. It's way too big for our needs, but it's the smallest inverter/charger they make for 120V/60Hz.

4) Just 120W of solar power on the dodger, but this is enough to keep up with the parasitic loads from the monitoring electronics in case the shore power goes away while we're away.

For the starting battery, we've just got a cheap Group 24 starting battery that will be maintained by an Orion-TR 3 stage DCC charger from the house bank. The charger itself will be controlled via some logic from the Victron setup (using Node-Red and outputs). With everything talking together (battery, inverter/charger, solar controller, alternator regulator) you get pretty much the most optimal setup you can.


Our actual usage pattern is to let the thing sit mostly charged at the dock, remote signal it if we want to go to full charge before leaving, then we have enough battery capacity to make it through at least a long weekend away from the dock without having to worry about recharging. Plus, if we tie up at our friend's dock, which does have an outlet that craps out if you go above about 10A, we can use the Victron to limit how much power we pull as we recharge the batteries.

We now have most of the components, we're just waiting on the hydraulic crimper so we can start building cables.