LiFePo4 for DUMMIES

[steelwrk1]

25-09-2013, 13:13 #2944
steelwrk1
Registered User


Join Date: Sep 2013
Location: Montreal Canada
Boat: Bayliner , 2001 4788 Pilothouse
Posts: 21
Images: 2
Re: LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks
Hello T1 Terry and Ebaugh,

Hello All,

In my first post (partially copied above) in the original thread on LiFeP04 Batteries for house banks above I thanked Ebaugh and T1 Terry for their input and guidance.

I have continued to read ALL i can find in this Cruisers Forum and try to check it as often as possible to come to understand more about the system of 1260 amp hours LiFeP04 I have.

Mine are presently in my heated garage resting at 50% capacity till next May when I will re-install them. Its winter here now and our boats are on the hard.

I just wanted to post how much MAINESAIL with all his continued support of these now numerous posts has helped me.

I do not know the man, have never contacted him, and do not intend to.

His honest , continued, and sometime criticized posts here are what I want to just stop and say THANK YOU for.

All the negativity will always be there in anything we do but if someone wants to really do his homework everything is here...just do the work.

Best Regards,
Pete

[folivier]

Gotta agree with you Pete. I've received valuable information from the guys here which has given me confidence above all else to tweak my LiFePO4 system.
I won't mention names cause I'm sure I'll forget someone but thanks again!

[steelwrk1]

Originally Posted by folivier

Gotta agree with you Pete. I've received valuable information from the guys here which has given me confidence above all else to tweak my LiFePO4 system.
I won't mention names cause I'm sure I'll forget someone but thanks again!

Hello Foliver,

Your a smarter man than me, I also really appreciate the posts of Deckofficier and others I should mention, but the patience MAINSAIL has displayed here made me single him out.

Lots of great people here and valuable " Been there, Done that " knowledge, combined with honest reports re this technology as it develops.

I admire and respect the "give back" from those who take their time to post here.


Best Regards,
Pete

[botanybay]

Originally Posted by dlentz

Maine,
I had some time this am and happened across an older Jack Riccard video about the cellog 8. It makes want to remind you to remind others that those very small voltage sense wires need to be fused! Sending virtually unlimited amps though +/- 20 ga wires and a very small moldex plug isn't pretty.

As for the other stuff, Geez, it's all here. Equipment, links, sources, theory and much advice. It's even been broken down into it's simplest forms.
Don't listen to it.
Dwain

Another trick is to put a resistor at the battery (fuse may be easier in many ways) which limits the current in the wire to an acceptable level. This only works for "sense wires" which have virtually no current flow and thus virtually no voltage drop over a relatively high resistance. The one advantage to this (and potentially a fuse to boot) is that if you short out the sense wire it does not blow the fuse, just a small current flows, this can be useful for a "test point" where someone may be poking around with volt meter probes.

Just a thought.

David

[botanybay]

First I want to express my appreciation to all of those who have been pushing this technology forward. I have been reading with great interest for the last couple of years (mostly) as a lurker interested in how the technology is working.

I am in the process of restoring a new to me vessel and while I am not quite ready to replace the batteries I am in the process of upgrading the electrical system and the information was very helpful in selecting equipment which will (hopefully) be workable when I eventually migrate to LiFePo4

I did choose Victron gear and specifically the following hardware:

Victron Quattro 8kva 230V inverter / 200A @ 24V charger
Victron automatic input adjusting isolation transformer (3.6 kva)
Victron Skylla-I 100A 24V charger
Victron Pheonix 1200 watt dedicated 120V inverter
Victron Pheonix 300 watt dedicated 120V inverter for the nav station.

I am currently integrating the hardware with the existing 440AH @ 24V wet cell golf cart battery bank which is 5 years old. My thought was to get the bugs out of the system before replacing the battery bank which will need to happen in the next year or so (actually voltages, electrolyte specific gravity, and available capacity are well in spec so who knows how long they might go).

The question is: To migrate to LiFePo4 when the bank dies or do the drop in AGM thing until I am ready to go cruising in about 8 - 9 years.

I expect to continue to be predominantly at the dock with 15 to 20 three day weekends away from the dock during the year, the rest of the time the system is in liveaboard mode.

In liveaboard mode the isolation transformer can handle 3.6 kva so any power consumption above that (as much as 12 kva worst case for short periods) is pulled from the batteries by the Quattro and supplements the incoming AC power. As soon as the load is removed the batteries could be (in the case of LA are) recharged.

Thus, these batteries are going to see a significant number of short cycles just sitting at the dock over the next 7 - 8 years which might drive me to feel the need to replace the bank prior to several years of cruising?

As others have suggested, if I stick with LA technology for the time being I may very well put a small LiFePo4 bank up forward for the windlass (and potential bow thruster in the future) just to start tinkering with a small bank.

Thanks again everyone for their efforts bringing this technology forward, I even see some polymer technologies out there which may bring even higher energy densities!

David

[senormechanico]

Originally Posted by botanybay

Another trick is to put a resistor at the battery (fuse may be easier in many ways) which limits the current in the wire to an acceptable level. This only works for "sense wires" which have virtually no current flow and thus virtually no voltage drop over a relatively high resistance. The one advantage to this (and potentially a fuse to boot) is that if you short out the sense wire it does not blow the fuse, just a small current flows, this can be useful for a "test point" where someone may be poking around with volt meter probes.

Just a thought.

David

Excellent idea. Thanks.

[IceDog]

I just ordered four 700AH batteries from Balqon and they currently have a promotion of free shipping, which is a significant savings from California to Florida. (about $1200 if I remember right on the 700 AH sets). The 400AH sets were only around $350 for shipping when I checked last year but it jumped up to $1200 for the 700AH ones...My cost for 4 batteries plus the busbar was $2826 delivered.
-Kevin

[deckofficer]

$706.50 per cell with bus bars and shipping is a real deal. Keep us posted as to delivery time, Balqon has an image problem there. You are going to be very pleased with the performance of these cells. I've cycled mine 340 times to 80% DOD, still has the same 17% over rated capacity.

[IceDog]

The batteries were listed as in stock with shipping available in 3 or 4 days. However, I asked for the order to be shipped for arrival around April 9. The marina will hold stuff for 5 days so I didnt want them to arrive early... before I do. I have read all the threads so I am aware of previous issues. I will keep the furum advised of my delivery experience. So far the customer service has been good although the sales rep in the online chat was not at first aware of the free shipping promotion. They were very helpful so far!
Kevin

[folivier]

Wow, I really got a deal on my 4 1000 ah cells. I paid $740/cell and $288 for shipping to Louisiana. That price included the BMS and 1 contactor.
Have they gone up in price that much in just a few months?
Yes, Balqon does need to improve their customer service and shipping time. If you can get Mr. Samra on the phone he is very helpful and pleasant to talk with.
BTW my Freedom 2500 inverter is charging correctly now. The voltage finishes at about 14.0volts.

[deckofficer]

Folivier, have you had a chance to pull down to 80% DOD? Just curious how much more boondocking you can do now vs the lead pack?

[folivier]

Not yet. The lowest I've been is about 65%. I'm waiting for a few days of cooler weather when I won't need the air conditioner and have the time to hang around.

[deckofficer]

Run the A/C on the batteries, that will get you to 80% DOD.

[KASHMIR]

I have been watching with interest the Lithium battery market for some years now, I have been trying to keep ahead of the market with perhaps a view to one day using all that knowledge. So last year I was in a position to spend a lot more time and start to develop a business model around the batteries. I have found the information posted on this site invaluable to my knowledge of how they are used by the end user and I thank the people here for sharing their experience.
I have started importing batteries and selling them to local users. I have found that trying to explain to people about banks of with BMS's and changes to fundamental parts of the electrical system just made people eyes glaze over and they very rapidly lost interest, I have had the most success with drop in units that I have made to my specs that have built BMS and can be paralleled to get up to 400Ah. I understand that the customers are not getting the maximum from their installations because most standard alternators only charge to about 14.2V, some people have adjustable regulators that I can bump the voltage up a little higher but that the is the most we ever do.
Take out the LA and drop in the LiFePO4's, thats it and it works.
My batteries are similar to the Fusion ones noted earlier in this thread, but not the same. I cannot believe the performance from them, my little 20Ah engine cranker will turn my engine over for 45minutes!
Over time the market may become more accepting to updating the complete system to get the maximum from individual cells and I will keep pushing it.
As I say to my customers, sure it cost more now and the built in BMS batteries are a lot more expensive than external BMS but seem to be worry free.

Peter (Melbourne, Australia)

[deckofficer]

Originally Posted by KASHMIR

my little 20Ah engine cranker will turn my engine over for 45minutes!

Peter (Melbourne, Australia)

Really? How long with the spark plugs in? lol