Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rating: Thread Rating: 34 votes, 4.82 average. Display Modes
Old 26-04-2013, 05:02   #2626
Marine Service Provider
 
Maine Sail's Avatar

Join Date: Jan 2007
Location: Maine
Boat: CS-36T - Cupecoy
Posts: 2,903
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by T1 Terry View Post
Charging with a constant voltage of 13.8v is very slow to get the last 10% or more in, fine if you have plenty of time, a higher charge voltage is required if time is limited but you need to get near fully charged before you stop the charge cycle.

I have not found this to be slow at all, but perhaps for Li it is slower in the top end.. I don't find my bank really limiting much until into the high 90's as a % of charge. Just yesterday I was still pumping 24A of current in at 99% SOC and it was declining.

It ran the alt at full tilt for a solid 30 minutes before the current began to reduce when the bank hit the target voltage. Unlike LA batteries, when I say "reduce", it went from 130A down to 125A and very slowly tapered but I was already into the high 90's (above 96% SOC) when this occurred.

I had dropped the bank back to 81% SOC then fed it with the alt. Initially it was running at about 151A then when it got warm settled in at about 132A to 128A. I walked up to the sail loft and when I got back 30 minutes later the alt was still in the 110A range but the banks was nearly full or as full as I'd need in a short run.

I have never in my life seen a bank get back to 98-99% SOC so fast especially at 13.8V.... Yes, I could certainly push higher, but for now I am choosing to manually push the voltage up for the BMS to balance but only when the cell logger shows me the cells are "out". Thus far, after about 60 cycles, the cells are still in-balance to within 0.01V.... No complaints.

You are 100% correct that a single v-belt will easily get destroyed. An alternator not up to the task will also get fried. I am also using an alternator temp sensor to cut field based on alt case temp. Mine will run in the high 120A range for a long while and still remain below the alt temp limit.... I am using a 10 cog "J"/Jason industrial serpentine belt to drive the alt..
__________________

__________________
Marine How To Articles
Maine Sail is online now   Reply With Quote
Old 26-04-2013, 05:34   #2627
Registered User
 
NahanniV's Avatar

Join Date: Mar 2011
Location: On the Boat
Boat: Finnsailer 38
Posts: 1,027
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Maine Sail:

Are you using your LiFeP04 bank to start your engine ?
Any problems, or imbalance caused by this ?

How did you end up managing your backup AGM ?

Cheers,
JM.
__________________

__________________
NahanniV is offline   Reply With Quote
Old 26-04-2013, 05:43   #2628
Marine Service Provider
 
Maine Sail's Avatar

Join Date: Jan 2007
Location: Maine
Boat: CS-36T - Cupecoy
Posts: 2,903
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by NahanniV View Post
Maine Sail:

Are you using your LiFeP04 bank to start your engine ?
Any problems, or imbalance caused by this ?

How did you end up managing your backup AGM ?

Cheers,
JM.
Starts the engine with vigor. No issues.. Course my engine starts in a duration of about .75 seconds.. The AGM is charged via a Duo Charge for now or BOTH if I decide I needed that. I may still wire an A/B to the solar to give it absorption voltage every now & then..
__________________
Marine How To Articles
Maine Sail is online now   Reply With Quote
Old 26-04-2013, 14:19   #2629
Registered User

Join Date: Oct 2011
Location: Winter Bahamas - Summer BC
Boat: Lagoon 450, Bavaria Vision 40
Posts: 599
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by T1 Terry View Post
...

A few things we found,
it's better to limit the alternator max current to around 60% of it's capacity, easier on the drive belts and on the alternator itself, slipping drive belts add a lot of heat into the alternator rotor and they don't live long when you do that. Methods of limiting that output are varied, mine was to use an inverter and mains charger, unfortunately I had already stuffed the alternator by that stage.
.......
T1 Terry
Hi T1 Terry

I would like to get more information on how you drove and controlled an inverter from the alternator to run a regular charger. I would like to drive a Victron Multi charger from the two alternators on my cat. It would be easy to program the Multi charger values with a PC connection to experiment with the LiFePOs.

Rolf
__________________
roetter is offline   Reply With Quote
Old 26-04-2013, 15:17   #2630

Cruisers Forum Supporter

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

I have seen an alterantor belt literally hump up like an inchworm and climb off a pulley when a heavy load kicked in, so proper tension and alignment become critical if the alternator ig oign to engage a heavy load. Which is why some external regulators have a "soft start" to prevent that shock on the belt.

But in my limited experience I've never seen an alternator actively regulated to a set % of it's full capacity. That could easily be done with conventional power regulator circuits but that would also be pointless. An alternator's coils should saturate as the load comes up, and given adequate cooling the first thing to overheat is normally the diodes. By using oversize diodes that can tolerate the max output, you turn the alternator itself into a limiting factor. Or, have an alternator shop rewind it with less feet of thicker wire, which should reduce the output and raise the heat tolerance, again self-limiting it without the need for a regulator.

Of course some alternators are specified as "farm and industrial" use rather than automotive, and they usually can handle heavy loads much better as well.

Either way it should be a fairly simple job.
__________________
hellosailor is offline   Reply With Quote
Old 26-04-2013, 15:37   #2631
Marine Service Provider
 
Maine Sail's Avatar

Join Date: Jan 2007
Location: Maine
Boat: CS-36T - Cupecoy
Posts: 2,903
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by hellosailor View Post
I have seen an alterantor belt literally hump up like an inchworm and climb off a pulley when a heavy load kicked in, so proper tension and alignment become critical if the alternator ig oign to engage a heavy load. Which is why some external regulators have a "soft start" to prevent that shock on the belt.

But in my limited experience I've never seen an alternator actively regulated to a set % of it's full capacity. That could easily be done with conventional power regulator circuits but that would also be pointless. An alternator's coils should saturate as the load comes up, and given adequate cooling the first thing to overheat is normally the diodes. By using oversize diodes that can tolerate the max output, you turn the alternator itself into a limiting factor. Or, have an alternator shop rewind it with less feet of thicker wire, which should reduce the output and raise the heat tolerance, again self-limiting it without the need for a regulator.

Of course some alternators are specified as "farm and industrial" use rather than automotive, and they usually can handle heavy loads much better as well.

Either way it should be a fairly simple job.
Limiting alternator output is quite common with external regulation. With the Balmar regs you can set this with belt manager or just dial it back. The alts run cooler, the belts last longer and when the owner is ready to address his belt and pulleys he already has the "large" alternator and all he needs to do is turn it up... The alt temp sensors do the exact same thing by reducing the field when the alt heats up beyond safe levels....
__________________
Marine How To Articles
Maine Sail is online now   Reply With Quote
Old 26-04-2013, 18:48   #2632

Cruisers Forum Supporter

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

Maine-
You're right of course but I wasn't really thinking of that as regulating the alternator. They all work by lowering the self-excitation, which in turns limits the amount of power that can be produced. Which of course IS effective regulation...I was just thinking the other way around, of letting the "black box" run as hard as it wanted to, and performing the regulation out side of it. (Rather than by feedback from the regulator and back into it.)
__________________
hellosailor is offline   Reply With Quote
Old 27-04-2013, 00:00   #2633
Registered User

Join Date: Jul 2011
Location: Australia NSW south coast
Posts: 616
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by Maine Sail View Post
Limiting alternator output is quite common with external regulation. With the Balmar regs you can set this with belt manager or just dial it back. The alts run cooler, the belts last longer and when the owner is ready to address his belt and pulleys he already has the "large" alternator and all he needs to do is turn it up... The alt temp sensors do the exact same thing by reducing the field when the alt heats up beyond safe levels....

I was thinking or a similar idea to control alternator output, pulse width modulation to achieve a desired max current output, then as the load reduced the on pulse could be extended.
The Inverter and charger will probably be the easiest to do though, I'ce already rewired my feeds into the inverter to drive it from either the start battery or the house battery, with provision for both to be on just in case the start battery is flat so I can use the house battery to power the starter. Needed this a few time while we were away, even when the Li batteries were on their knees with a cell at 2.85v under load, there was still heaps there to start the 4 cyl diesel with a great deal of enthusiasm :lol:

Quote:
Hi T1 Terry

I would like to get more information on how you drove and controlled an inverter from the alternator to run a regular charger. I would like to drive a Victron Multi charger from the two alternators on my cat. It would be easy to program the Multi charger values with a PC connection to experiment with the LiFePOs.

Rolf

I used 2 H/D 12v solenoids with a 100% duty cycle wired to self illuminated rocker switches. One solenoid in the positive cable from the start battery to the inverter, the other solenoid in the cable from the house battery to the inverter. With both solenoids switched on, the two batteries are linked at the inverter, when the engine was running, I turned the house battery solenoid off and turned the battery charger powered by the inverter on. You can't use a combined inverter/charger, the battery charger must be a stand alone unit small enough for the alternator to be able to run 24/7, about 60% of the alternator output is about the limit. If I'd had the presence on mind to do this in the first place rather than on the side of the road 2 weeks into the trip, I could have saved myself a lot of headaches, 6 fanbelt replacements and a stuffed alternator, live and learn I guess. I just ran out of time to fit the solar panels before I left, so the emergency back up became the main charging system, and it wasn't up to the intended task by a long shot.
Turns out, the previous owner had a lot of electrical problems, the alternator was changed a few times, the last time they fitted an 11A section belt pulley instead of the required 13A section pulley, the load tore the belt v section in minutes, a 120 amp alternator with a single pulley is asking a lot in the first place, using the wrong pulley was a recipe for failure. There is no room to fit a double pulley or a flat belt pulley, there are 3 belts on there now and it's a climb inside and underneath to remove each belt, luckily it's the middle belt that's the problem but the radiator and fan shroud doesnít provide much room to work in. at least in a boat you donít have these things in the way so lifeís a bit easier there, but I did have the side of the road to stop on when a belt left the building, you donít get that luxury in a boat.

T1 Terry
__________________
T1 Terry is offline   Reply With Quote
Old 30-04-2013, 07:44   #2634
Marine Service Provider
 
Maine Sail's Avatar

Join Date: Jan 2007
Location: Maine
Boat: CS-36T - Cupecoy
Posts: 2,903
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Arghhhhhh.

Somewhere in the process of installing my bank I lost the cell level volt sensing cable for my Cell Log 8S (the multi-pin one).

I now can't seem to figure out what that part number is or if ANYONE in the USA stocks it? I know it was a separate line item when I ordered the Cell Log 8S but now can't put my fingers on it.

The Cell Log 8S took 7 weeks to get here from Hobby King so I hate to go through that again for a $2.00 part........

Part number anyone? USA source?
__________________
Marine How To Articles
Maine Sail is online now   Reply With Quote
Old 30-04-2013, 07:49   #2635
Registered User
 
neelie's Avatar

Join Date: Oct 2007
Location: On the boat
Boat: Valiant 50
Posts: 514
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

If its the 5 wire mini plug with tails, PM me your address, I'll throw one in the mail.

I have a couple of spares.

I'm in Hong Kong - you should get it in a week,

Cheers
__________________
The light at the end of the tunnel are no longer the headlights of the oncoming train......yippee
neelie is offline   Reply With Quote
Old 30-04-2013, 07:59   #2636
Registered User
 
NahanniV's Avatar

Join Date: Mar 2011
Location: On the Boat
Boat: Finnsailer 38
Posts: 1,027
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by NahanniV View Post
It's a "JST-XH" connector (.1" spacing). I got a 5 pin (for 4 cells) cable from a local hobby store that caters to electric Remote Control Hobbies. This is commonly called a balance connector in the hobby world.
Here is the Canadian company listing where I bought mine:
http://www.greathobbies.com/producti...od_id=TGHX1012

I'm sure you can find one locally.
__________________
NahanniV is offline   Reply With Quote
Old 30-04-2013, 07:59   #2637
Commercial Member
 
CharlieJ's Avatar

Cruisers Forum Supporter

Join Date: Dec 2008
Location: St. Petersburg, FL
Boat: Gulfstar Long Range Trawler; 53'; BearBoat
Posts: 815
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

RC-
Here is where I got my 8S JST-XH Pigtail. The company's name is appropriate ;-)

Progressive RC
6906 15th Ave NE
Seattle, WA, 98115
(443) BATTERY
__________________
Charlie Johnson
JTB Marine Corporation
"The Devil is in the details and so is salvation."
CharlieJ is offline   Reply With Quote
Old 30-04-2013, 21:06   #2638
Registered User

Join Date: Jul 2011
Location: Australia NSW south coast
Posts: 616
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

these people make very good quality plug and lead set eBay Australia: Buy new & used fashion, electronics & home d
i am trying to get them to make the pug and leads for the alarm port, the wires that come with the Junsi cell logger are very flimsy and break off at the plug ib no time.

T1 Terry
__________________
T1 Terry is offline   Reply With Quote
Old 10-05-2013, 05:13   #2639
Registered User
 
ebaugh's Avatar

Join Date: Dec 2011
Location: On the boat
Boat: DeFever 44
Posts: 525
An interesting chart from Balqon I had not seen before. Only a glossy sales brochure with no detail on what testing was done to derive the chart. But it clearly shows the hopeful case for ROI on LFP banks.
Attached Thumbnails
Click image for larger version

Name:	image-1263590575.jpg
Views:	158
Size:	271.7 KB
ID:	60620  
__________________
ebaugh is offline   Reply With Quote
Old 10-05-2013, 05:22   #2640
Senior Cruiser
 
Talbot's Avatar

Cruisers Forum Supporter

Join Date: Jun 2004
Location: Brighton, UK
Boat: Privilege 37
Posts: 3,578
Images: 32
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

Quote:
Originally Posted by ebaugh View Post
An interesting chart from Balqon I had not seen before. Only a glossy sales brochure with no detail on what testing was done to derive the chart. But it clearly shows the hopeful case for ROI on LFP banks.
It also shows that the AGM batteries are not the panacea that their advocates claim.
__________________

__________________
"Be wary of strong drink. It can make you shoot at tax collectors - and miss."
Robert A Heinlein
Talbot 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 05:24.


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.