Small Boat Electrical for Sail

[rgleason]

It has been awhile, but I think I have some better answers about fitting the SI28 to 3YM30 in my particular installation.


Calculation of the distance between the inside face of the aft alternator bracket and the back of the alternator
- Balmar 90-65a existing 1.75"
- Delco SI28 -1.52" Not including the 9mm/.35" required cooling gap.
___________________________

Equals 0.23" <---additional space at the back of the Delco SI28 in addition to the existing space with the current alternator.


The notes state "This space (9mm) must be clear at the back for cooling". So since 3/4 of the back is completely clear and the other 1/4 will have about 3/4" additional clearance, I believe it will be ok.


So, provided I can make the right brackets, get the right pulleys, modify for external regulation and possibly external diodes, get the B+ stub out behind the manifold and change the coolant piping to pull it forward, it should work.


Two attachments: 1 sketch, 1 Delco dimension jpg

[rgleason]

Since I've determined that the Delco SI28 160a #800312 will likely fit. The next things I need to do are:
1. Find one and test the installation, possibly from DB Electrical
2. Modify for external regulation See Q Xopa thread here
3. Determine if it is practical to make the rectifiers remote.
4. Possibly change rectification to mosfets too reduce heat output. See https://ieeexplore.ieee.org/document/8362385 and Perfect Switch Single Rectifier who I have written, but this may not be practical.
5. Confirm pulleys and belt sources.
6. Make mounting brackets.
7. Extend system coolant piping forward to miss the new belt.

[seandepagnier]

rick,


I have not actually read all the posts, but I suggest you do not consider lead acid batteries. I no longer use them and hopefully never will.


You should look at LiFePo4 which have significantly better efficiency cycle and and don't need to be kept in a high state of charge so you can use half the capacity or less. This ends up making them cheaper overall. I got 40ah cells for $65 on batteryspace.com, you need 4 cells to make a battery.



The only possible downside is you cannot charge them below freezing. You can discharge and store below freezing. I'm looking myself to add a controller which heats the batteries from the input power before allowing power into them if it's really cold, but I don't think you use the boat in winter anyway?

[rgleason]

Originally Posted by seandepagnier

rick,
I have not actually read all the posts, but I suggest you do not consider lead acid batteries. I no longer use them and hopefully never will.

You should look at LiFePo4 which have significantly better efficiency cycle and and don't need to be kept in a high state of charge so you can use half the capacity or less. This ends up making them cheaper overall. I got 40ah cells for $65 on batteryspace.com, you need 4 cells to make a battery.

The only possible downside is you cannot charge them below freezing. You can discharge and store below freezing. I'm looking myself to add a controller which heats the batteries from the input power before allowing power into them if it's really cold, but I don't think you use the boat in winter anyway?

Dear Friend Sean,


Thank you for your post, I am in complete agreement about LiFePo, the only other alternative would be Odysey carbon batteries from Ocean Planet that do not suflate and can be recharged several times to bring them back up to full capacity. I am happy to hear you've had success with LiFePo4, it is reassuring.

You are right about the winter. Ideally would like to leave the batteries in the boat (Rhode Island gets down to LiFePo Low Temp limit of (-5c / 20f, typically 2-4 times per year for short periods). I expect the inside of the boat would reach those temps too. So perhaps a small solar panel and a resistance mat with a temperature cutoff would help heat the batteries up during the day so they can ride through the night? I am thinking it would be best to disconnet the batteries and let the 3% discharge rate due to the BMS just continue. Then once or twice during the winter check the batteries.

I will check out batteryspace.com.


Best, Rick

[rgleason]

I would like to have the alternator charge the LiFePo4 directly.The Balmar Regulator will be programmed for LiFePo4 with no float for sure and custom settings for LiFePo4.

Protection of the Alternator

I realize now that our 3 -way battery switch has an alternator field disconnect which currently is not used, would protect the alternator from indescriminate switching through OFF position, but the alternator would still not be protected if the future LiFePo4 BMS were to shut down while the alternator is working.

Perhaps an ACR or Perfect Switch Relay (expensive, but about the same cost as ACR) would help to keep the alternator connected to a load so it does not fry?

Another practical way to protect the Alternator is to perhaps use a Zap-Stop or a small FLA battery wired in parallel? -The voltages won't be right for the small battery, but FLA is perfectly happy at 13.8volts, and it would still start the engine as backup. Is there any problem wiring it in parallel with the LiFePo4?

[rgleason]

Configuration: Hybrid LA/LFP Frans' take on a hybrid LA/LiFePO4 system
which uses a smaller FLA battery in parallel to protect the Alternator when the BMS cuts off the LFP Batteries.

These two threads were helpful:
Balmar 614 vs Li battery BMS cutout
Please critique my wiring diagram

[rgleason]

Nordkyndesign Lithium Dual Bus and Hybrid LFP
At the bottom after Dual Bus section, excellent wiring and configuration information about Hybrid LFP

Correct FLA Battery Size for Lithium Hybrid Configuration

Properly sizing dc busbars

[rgleason]

Starter Fuse -Marine How to
For our 3ym30
"Minimum fuse size for small sailboat diesel AUX engines 8HP to 35HP = 250A"


For good flexible use of 3-way Switch -Marine how to look at last config.

[rgleason]

We have another excellent resource for LFP configuration that switches to FLA when the BMS cuts off LFP for overvoltage, using separate charge and load discharge buses and 3 PerfectSwitches to protect the Alternator and the entire system. The two Perfect Switch Mosfets settings are for emergency protection "system failure incidents" should the BMS not work properly or something else happen. "In the best possible design we want the whole system to work properly without ever having to operate one of these relays."

Perfect Switch Marine-Lifepo4-Lithium Ion on Mai Tai

[rgleason]

I like the Rec-active BMS because of it's clear instructions and documentation, the active balancing is nice, and it has been around a long time, since I looked at it originally. There are other less expensive BMS but I don't think I could go wrong with this.

Note & warning: I have not implemented any DIY LFP battery yet. There are many others on this forum who have had large LFP battery systems with BMS and solar, who are a good resource too.

I have been studying BMS/LFP configurations and have learned that:

1. All charging systems (shore power, alternator and solar) must first have charge routines setup purposefully for LFP such that they work properly without triggering the BMS protections.
2. All discharge devices also needs to be managed and controled to protect the LFP without triggering the BMS.
3. Then the BMS is used to monitor and balance individual cells and provide the ultimate protection for the LFP, providing automatic disconnection for undervoltage/overvoltage on both the charge an load/discharge buses, if you have them.
4. In the event the BMS shuts off the LFP battery, the charging devices, such as the Alternator diodes need to be protected from damaging cutoff spikes. BMS cutoff
5. This is why configuration of the electrical system is so important.

External Regulators compatible with LFP
Wakespeed WS500 Can sense current when connected to a shunt, has battery and alternator temp sensors, uses Canbus and other BMS connections. "connect the regulator to a current shunt to determine battery condition and electrical loads in real time". Integrates well with BMS, via Canbus, compatible with Rec-active BMS. See also OceanPlanet Energy comment

Balmar MC-614 Does not have current sensing, but is compatible with LFP charging, has battery and alternator temp sensors.

also Balmar ARS-5 - does not have a separate power wire, sense wire is the same as the power wire. Ok for <150a charging, and has user programmable settings so it can be setup for LFP too! has battery and alternator temp sensors.

• 5 Selectable Programs for Marine Batteries
• 9 Amp Maximum Field Current
• Appropriate for 6-Series Alternators (150A and below)
• Single Engine, Single Alternator Applications Only
• All the Same Programming Functions as the MC-614

Balmar has the Battery Monitor SG-200 and I expect that that will integrate with a new Balmar regulator eventually, to give much the same advantages as the Wakespeed WS500. However I do not actually know this!

[rgleason]

REC active BMS has a BLE Bluetooth Low Energy Module for IOS and Android Phones which would allow us to monitor the state of the BMS and LFP.

[rgleason]

Balmar MC-614

- no current sensing issue.

See Firefly Battery Operation Post #202

Does not ..."use a current shunt to monitor acceptance current and when it drops to less than a preset percentage of battery capacity, it drops the acceptance voltage down to float."

like Wakespeed WS500

However for LFP I think BMS SOC should be one of the factors used to shut down the Alternator!
LFP does not like to be overcharged, and does not like remaining at 100% SOC for long periods of time, but we do need to get to a high state of charge occassionally to balance the LFP cells!

So keeping track of state of charge and accurate coulomb counting would really help. The BMS has this information normally.

[rgleason]

I found the excellent diagram attached below for 30a/120v Shore Power to Panel which I had saved from some other valuable post, perhaps CharlieJ.

SV/Jedi advised regarding Isolation Transformers and meeting America and European Shore plugin Standards:

The transformer will not convert the 50 <> 60Hz frequency. The best option is to have a battery charger that accepts either frequency, which you feed from the isolation transformer and which charges your batteries. Then you just use your inverter to power everything aboard so that you always have the correct frequency.

Stirling Chargers, Victron Energy ITR040362041 Isolation Transformer 3600W 115/230V 32/16A with autodetect input voltage and others will provide input voltage range of 90-270v and 40-70hz Victron does not meet ABYC standards.

Isolation Transformer vs Galvanic Isolator - Isolation Transformer is the gold standard.

ELCI Panels like Blue Sea 8101 120 Volt AC Circuit Breaker Panel with ELCI Main

I still don't know the best way to setup the boat for a 230vac 50hz connection to shore power. Perhaps the charger simply has two possible ways to be connected one 120vac/30amp/60hz and the other European 230v/16a/50hz, done simply by plugging the transformer into a different socket?

[rgleason]

This sailor's use of a Perfect Switch bidirectional SPDT mosfet for make before break switching between LFP and Start Batteries, is a good clean solution. "Endless search for Power"
https://www.cruisersforum.com/forums...ml#post3532138