Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rating: Thread Rating: 33 votes, 4.82 average. Display Modes
Old 04-05-2015, 14:34   #4486
Registered User

Join Date: Feb 2013
Location: WY / Currently in Hayes VA on the Chesapeake
Boat: Ocean Alexander, Ocean 44
Posts: 794
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by klaus53123 View Post
Hi Folks,

my installation is now complete since a month and I am very pleased with the result and the performance of the batteries.

Charging is stopped by the BMS (REC) at 13,8V (measured at the cell terminals) and this works very fine. Main charging is done with solar which takes it time as I cannot provide more than 35A at full sun shine. I start charging at cell voltage around 3,2 V which corresponds roughly to around 40% SOC.

There are only two questions left which confuses me a bit:

My solar chargers can only be limited to max charging voltage 14.2 V. I cannot adjust them further down. However once they charge with 14.2 V (measured directly at the output connection of the charger) I still see a voltage below 13,8 V at the Battery terminals. I assume they take the charge to fast, that voltage immediately drops. Now the question: do I overcharge or am I safe with 13,8V cut off at the terminals despite the fact that the solar chargers provide voltage in excess of the 13,8V?

Second question: I have a Victron Battery Monitor installed which allows to adjust for Peukert values and charging efficiency. Any recommendations what I should enter there?

Many thanks for your help

Klaus
I've been told that the Peukert factor is so close to 0 that 0 should be entered.

I would take the time to watch the voltage at the battery closely at least a couple of times when they are fully charged or very nearly so. If the current is very low the loses in the wires/connections may be less so voltage may climb a little?
__________________

__________________
darylat8750 is offline   Reply With Quote
Old 04-05-2015, 18:19   #4487
Registered User
 
Highland Fling's Avatar

Join Date: Mar 2007
Location: Sunny Scotland but sail in the Caribbean
Boat: Beneteau Oceanis 461
Posts: 369
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by OceanSeaSpray View Post
Looking at the little shunting cell boards, if the BMS is the same (CM200) as installed by Highland Fling, good luck to all of them!


It seems to cost a few hundred bucks regardless of cell size to fully protect a bank properly and reliably - at least it has been that way for me. Some of that cost was in the disconnectors as I have used Tyco BDS-A units, one for the charge bus, one for the load bus. Very nice gear, but a bit costly for sure. Still, unlike with many canned "solutions", you only buy them once.

I am seriously curious re your reasoning thinking and logic behind the need for a dual bus. I understand the theoretical need for one but cant really work out when you woud need one in reality.

As these LFP batteries are 'new' technology <SIK> we are not going to fit and forget about them.

In fact as long distance cruisers and heavy users of our LFP batteries I would say we get a little anal with our abilities to look at and monitor individual cell voltages. ('we' being people who have LFP batteries)

I expect by next year I will be in a fit and forget mode and look at them 'occasionally' probably twice monthly but of course daily monitor fairly closely (as I have done in the past with LA batteries) Ah used, at bed time, the morning and around 14:00 hrs.

The big change is that my VE 602 energy monitor does not tell fairy stories any more, so if it says I have used 20% with 80% remaining that is an accurate representation of the charge state of my batteries unlike in the past with all the variances you have using LA batteries.
__________________

__________________
Now with 600AH of LIFEPO4
kindest regards
David
Highland Fling is offline   Reply With Quote
Old 06-05-2015, 08:49   #4488
SFH
Registered User
 
SFH's Avatar

Join Date: Jun 2013
Location: Danish but living in Nigeria
Boat: Jeanneau Yacht 53
Posts: 62
Send a message via Skype™ to SFH
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by Highland Fling View Post
I am seriously curious re your reasoning thinking and logic behind the need for a dual bus. I understand the theoretical need for one but cant really work out when you woud need one in reality.

As these LFP batteries are 'new' technology <SIK> we are not going to fit and forget about them.

In fact as long distance cruisers and heavy users of our LFP batteries I would say we get a little anal with our abilities to look at and monitor individual cell voltages. ('we' being people who have LFP batteries)

I expect by next year I will be in a fit and forget mode and look at them 'occasionally' probably twice monthly but of course daily monitor fairly closely (as I have done in the past with LA batteries) Ah used, at bed time, the morning and around 14:00 hrs.

The big change is that my VE 602 energy monitor does not tell fairy stories any more, so if it says I have used 20% with 80% remaining that is an accurate representation of the charge state of my batteries unlike in the past with all the variances you have using LA batteries.
I was convinced about the need for two positive bus bars when I read this one from Genasun:

Dual Positive Bus: The Highest Level of Safety

Every Lithium BMS has a relay to disconnect the pack to prevent of over-charge or over-discharge. This ensures safety, and protects the pack from damage. Genasun's Dual Positive Bus is designed with two relays to separate chargers and loads.

Is it worth the additional parts cost?

With one relay, if the battery were to disconnect due to a malfunctioning charger, chargers and loads would be connected directly together, without the stability of a battery. Results could range from unstable operation to system-wide damage due to the potential for a load-dump voltage spike.

With two relays, the Genasun pack can disconnect the failed charge source, run all your electronics, prevent over-voltage, and reconnect the charge source when appropriate. Your power is maintained.

On the other hand, if you're sailing into port at night and drain your battery too low, the separate load bus will disconnect, while leaving the charge bus connected. The reserve capacity in the bank will keep the emergency lights on while you find the genset switch. Alternatively, with one relay, you could hunt around in the dark.


I am preparing for a move to to Lithium and I install two bus bars as part of the migration

/Steen
__________________
SFH is offline   Reply With Quote
Old 06-05-2015, 14:24   #4489

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 12,112
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

I doubt that many of us would refer to a "dual disconnect relays" setup as "dual bus".


You've still got one bus with the Genasun setup, the only "dual" is that there are dual connection points and it gives you the opportunity to disconnect the failed component in a more logical manner.


Sounds like their marketing department came up with a new trademarked buzzword, like the battery charger folks who decided they don't make a 3-stage charger, they make a 4-stage charger, because "off" should be called a stage.


Ahuh, sure.


Send the Genasun marketing team to the penalty box for a timeout.
__________________
hellosailor is offline   Reply With Quote
Old 06-05-2015, 14:26   #4490
Senior Cruiser
 
SV THIRD DAY's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Morro Bay, CA
Boat: 1978 Hudson Force 50 Ketch
Posts: 3,183
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by hellosailor View Post
Send the Genasun marketing team to the penalty box for a timeout.

Or more likely send them on a Corporate Retreat vacation to the Islands for doing a great marketing job to justify the high price?....na...companies that sell to cruiser don't pull those tricks....
__________________
Rich Boren Living Aboard in Morro Bay, CA and the owner of:
Cruise RO Water High Output Water Makers
Technautics CoolBlue Refrigeration

SV THIRD DAY is offline   Reply With Quote
Old 06-05-2015, 14:47   #4491
Registered User

Join Date: Feb 2013
Location: WY / Currently in Hayes VA on the Chesapeake
Boat: Ocean Alexander, Ocean 44
Posts: 794
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

I would think that if I had several charge sources like solar (with possibly more than one controller), engine driven alt., a/c battery charger I would be inclined to put the charge sources to a separate bus (Charge bus?) with the high voltage disconnect between the charge bus and the battery bank. A load bus with the low voltage disconnect for the obvious reasons.
I can't afford Genasun's stuff but their terminology doesn't offend me.
__________________
darylat8750 is offline   Reply With Quote
Old 06-05-2015, 15:53   #4492
Marine Service Provider
 
Maine Sail's Avatar

Join Date: Jan 2007
Location: Maine
Boat: CS-36T - Cupecoy
Posts: 2,902
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by hellosailor View Post
I doubt that many of us would refer to a "dual disconnect relays" setup as "dual bus".


You've still got one bus with the Genasun setup, the only "dual" is that there are dual connection points and it gives you the opportunity to disconnect the failed component in a more logical manner.


Sounds like their marketing department came up with a new trademarked buzzword, like the battery charger folks who decided they don't make a 3-stage charger, they make a 4-stage charger, because "off" should be called a stage.


Ahuh, sure.


Send the Genasun marketing team to the penalty box for a timeout.
Mine is set up the same way two buses one for charging sources and one for loads, hence "dual bus". Charging and loads are not on the same bus and do not share a contactor/relay.. It is a dual bus system with two separate contactors to isolate which ever side of the system may be causing the issue, while leaving the other operational.
__________________
Marine How To Articles
Maine Sail is online now   Reply With Quote
Old 07-05-2015, 15:08   #4493
Sponsoring Vendor
 
OceanPlanet's Avatar

Community Sponsor

Join Date: May 2009
Location: Woolwich, Maine
Boat: Sold it!
Posts: 309
Send a message via Skype™ to OceanPlanet
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by hellosailor View Post
I doubt that many of us would refer to a "dual disconnect relays" setup as "dual bus".


You've still got one bus with the Genasun setup, the only "dual" is that there are dual connection points and it gives you the opportunity to disconnect the failed component in a more logical manner.


Sounds like their marketing department came up with a new trademarked buzzword, like the battery charger folks who decided they don't make a 3-stage charger, they make a 4-stage charger, because "off" should be called a stage.


Ahuh, sure.


Send the Genasun marketing team to the penalty box for a timeout.
Climbing out of the "Penalty Box" to answer this....

Just today I was told about another high-end brand Li system failure with a single positive bus, where the alts ran too high and triggered an HVC. Since on a single bus the charge sources are connected to...well, everything except the batteries if a cutoff....the resulting voltage spike fried all their inverter-chargers and host of other expensive devices.

With a dual bus the sources are separated from the loads. So if there is an HVC the offending source(s) are cut off, from not only the battery, but the loads as well. This protects everything on the load buss from such voltage spikes.

Of course some devices are both source and load (such as an inverter-charger). Typically we recommend inverter-chargers to be on the load bus as the most common issue with those is running down to an LVC with AirCon, etc. Depends on what the most likely use is, if primarily for charging then we put on the charge bus.

Attached is a generic dual-bus diagram, and also some various common system configuration diagrams showing dual bus setups. Note that usually we use two or more independent banks (each with it's own BMS) running in parallel effectively as one bank. This gives a level of redundancy; in the case of something bad happening to one bank then you can run off the other(s).

Just last summer Rich Wilson's IMOCA 60 GA4 was hit by lightning, which killed off one BMS, along with all of the instrumentation and more. However the other BMS (right next to each other!) survived and the boat could still be operated. Just an example of what can happen out there...
Attached Files
File Type: pdf Dual Buss Diagram.pdf (89.9 KB, 164 views)
File Type: pdf Genasun System Configurations.pdf (186.6 KB, 134 views)
File Type: pdf 60+ vessel sample Block Diagram.pdf (295.0 KB, 145 views)
__________________
Twice around was enough for me...
Now I just help others prep for ocean trips...
www.bruceschwab.com
OceanPlanet is offline   Reply With Quote
Old 07-05-2015, 17:36   #4494

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 12,112
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Let me put it this way.
To the average sea-cook, a donut and a coffee cup are very different shapes. But as any topologist can tell you, they are both identical toruses. Identical.


You call it two busses, I call the entire system one bus--and while it may be more logical to connect and disconnect portions of that bus in a sequence, or independently of each other, the "whole thing" is still one bus. Chargers, batteries, loads. Stagger the disconnects as you please, I'm still saying it counts as one power distribution bus, until you set off the demolition charges [sic] and break it in two. Or three if you blow them both.


There's never a topologist in the house when you need one.
__________________
hellosailor is offline   Reply With Quote
Old 07-05-2015, 17:36   #4495
Registered User

Join Date: Sep 2009
Location: Mackay,QLD, Australia
Boat: planning a approx 45ft cat
Posts: 3,406
Images: 3
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Useful post Ocean Planet. Thanks.
__________________
downunder is offline   Reply With Quote
Old 07-05-2015, 18:11   #4496
Registered User

Join Date: Feb 2013
Location: WY / Currently in Hayes VA on the Chesapeake
Boat: Ocean Alexander, Ocean 44
Posts: 794
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

HelloSailor,
You should see the electrical system on an airliner. Battery bus, Battery direct bus, essential dc bus, essential ac bus, left main ac bus, right main ac bus and on and on. If you called it all one bus when the s....t hit the fan you would have a hard time figuring out what worked and what didn't much less what you could do to keep the stuff you really need working.
__________________
darylat8750 is offline   Reply With Quote
Old 07-05-2015, 18:36   #4497
Marine Service Provider

Join Date: May 2011
Boat: Gulfstar 50
Posts: 666
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by hellosailor View Post
Let me put it this way.
To the average sea-cook, a donut and a coffee cup are very different shapes. But as any topologist can tell you, they are both identical toruses. Identical.


You call it two busses, I call the entire system one bus--and while it may be more logical to connect and disconnect portions of that bus in a sequence, or independently of each other, the "whole thing" is still one bus. Chargers, batteries, loads. Stagger the disconnects as you please, I'm still saying it counts as one power distribution bus, until you set off the demolition charges [sic] and break it in two. Or three if you blow them both.


There's never a topologist in the house when you need one.
Yes, and a circle, triangle and square are also the same to a topologist but that adds NOTHING to the conversation.

PS and strictly speaking a cup is a sphere... And a sphere is a degenerate standard torus where the axis of revolution passes through the center of the generating circle, rather than outside it. And thus belongs to a simpler class than a torus and thus is not a torus at all.
__________________
evm1024 is offline   Reply With Quote
Old 07-05-2015, 18:52   #4498
Sponsoring Vendor
 
OceanPlanet's Avatar

Community Sponsor

Join Date: May 2009
Location: Woolwich, Maine
Boat: Sold it!
Posts: 309
Send a message via Skype™ to OceanPlanet
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

I don't eat donuts or drink much coffee, so you kinda lost me there. ;-)
__________________
Twice around was enough for me...
Now I just help others prep for ocean trips...
www.bruceschwab.com
OceanPlanet is offline   Reply With Quote
Old 09-05-2015, 19:02   #4499
Registered User
 
SailRedemption's Avatar

Join Date: Feb 2014
Location: New Orleans
Boat: Kaufman 47
Posts: 564
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Alright, I have made a diagram of my battery bank. It will. Consist of 8 CALB 180ah batteries ran in series then parallel to form 360ah 12.8v bank.

I am no electrical engineer so my diagram is crude, and I don't have the symbols for everything but I think it looks labeled well enough. Does everything look in order, setup wise? I'm missing some wire gauges because I don't yet have some items so it's just there for diagramming sake.

Click image for larger version

Name:	uploadfromtaptalk1431217937134.jpg
Views:	286
Size:	303.6 KB
ID:	101684

As of right now, I have not added a BMS only a HVC and LVC relays for the house and charge buses. I'm understand the reasons for a BMS and I'm not against it. I just haven't figured out which BMS to use at the moment. It's just not on this diagram right now.

All charge sources (DC power solutions 160a alternator, balmar MC-614 regulator, Victron Multiplus 12/2000/80 charger/inverter, Silent Wind wind/solar controller) are capable of custom voltage settings which would all be 13.8v at the pack. The Victron BMV600 will alarm at 14.4v and the HVC relay will be at 15v. The load said, the BMV600 will alarm at 11.8 and the LVC relay will cutout at 11.4v.

I don't currently have the Victron or the Silent Wind system now.

But I do have a question about the victron multiplus. Since it charges and inverts from the same two batter wires, do I put them on the 'load' bus or 'charge' bus?

Be gentle. (:





- Ronnie...on the geaux
__________________
SailRedemption is offline   Reply With Quote
Old 09-05-2015, 19:52   #4500
Registered User

Join Date: Aug 2014
Location: Astoria, NY
Boat: Sabre 38
Posts: 272
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by SailRedemption View Post
Alright, I have made a diagram of my battery bank. It will. Consist of 8 CALB 180ah batteries ran in series then parallel to form 360ah 12.8v bank.

I am no electrical engineer so my diagram is crude, and I don't have the symbols for everything but I think it looks labeled well enough. Does everything look in order, setup wise? I'm missing some wire gauges because I don't yet have some items so it's just there for diagramming sake.

Attachment 101684

As of right now, I have not added a BMS only a HVC and LVC relays for the house and charge buses. I'm understand the reasons for a BMS and I'm not against it. I just haven't figured out which BMS to use at the moment. It's just not on this diagram right now.

All charge sources (DC power solutions 160a alternator, balmar MC-614 regulator, Victron Multiplus 12/2000/80 charger/inverter, Silent Wind wind/solar controller) are capable of custom voltage settings which would all be 13.8v at the pack. The Victron BMV600 will alarm at 14.4v and the HVC relay will be at 15v. The load said, the BMV600 will alarm at 11.8 and the LVC relay will cutout at 11.4v.

I don't currently have the Victron or the Silent Wind system now.

But I do have a question about the victron multiplus. Since it charges and inverts from the same two batter wires, do I put them on the 'load' bus or 'charge' bus?

Be gentle. (:





- Ronnie...on the geaux

A few questions. I don't have a system yet, but have been doing to research.

1) Is there a reserve battery? How do you plan on charging it? How will it be switched (ie, the 1-both-2-off switch)?

2) Where is your starter? Bilge pump?

3) On the HVC, normally, it appears, folks have been doing the cutoff not on the whole bus bar, but individually for each source. That is, the alt gets its own HVC and so does the solar. This is because each charger likes to be HVC'ed in its own way.

4) On the BMS, have you considered the House Power? Many here have used it.

5) The bank is wired funky. It has been said that you should parallel first then series. While I mean is make four sets of 360 amp 3.2 v cells then series to 12.8 v. You will only need one fuse and the BMS works better at measuring voltage. Something about how the paralleled cells hardly get out of balance.

6) Where you buying your cells from, if you don't mine me asking.


Sent from my iPhone using Cruisers Sailing Forum
__________________

__________________
1983 Sabre 38cb
My Intro
fallingeggs is offline   Reply With Quote
Reply

Tags
battery, lifepo4, LiFePO4 Batteries, sailing

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
LiFePO4 Batteries - Okay Tear Me Apart ;-) jallum Electrical: Batteries, Generators & Solar 395 03-12-2015 13:19
Voltage drop under load, amps read 99% ?? VVD Electrical: Batteries, Generators & Solar 25 28-06-2011 16:25


Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 12:47.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.