LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

[jff]

Terry

I assumed that with the new alternators, he'd be fitting external regulators. If thats the case cant the relay be used to cut the field wire, thus saving he diodes?

[ebaugh]

Probably, but the other issue is a complete and sudden loss of power. It really should never happen...but if it does, it always seems to be at the worst possible moment.

[T1 Terry]

Originally Posted by jff

Terry

I assumed that with the new alternators, he'd be fitting external regulators. If thats the case cant the relay be used to cut the field wire, thus saving he diodes?

If external regulaors are being used cutting the field current is a better option. The centrefielder looks like an interesting idea but wouldn't temp sensing regulators have the same effect by reducing the output from one alternator? The charging voltage would drop so the other alternator should take up the slack. Lithium ferrous batteries function quite ifferently from lead acid batteries, the terminal voltage doesn't climb as the charging current climbs, the voltage climb is related to reaching the end of charge requirement.

T1 Terry

[downunder]

[QUOTE=Lagoon4us;1064009]Hi all we are back in CROATIA after visiting the grandkids for three weeks, now the projects start and i'd like comment on the following prior to immediate purchase and installation over winter.

Totally appreciate all previous comment and would like to get final guidance and suggestions.

1) I have a BEP Monitor.
2) Will be fitting 850 watts of solar.
3) Existing Dolphin 80 amp charger.
4) Will fit 130 amp alternators on the Volvo main engines i'm told they have adjustable regulators.

Cheers Frank.QUOTE]

Frank,
As you have a electric galley an will be running your genset a bit is not another option to put in another decent inverter charger. Should be effective vs new alternators for your charging.

Just a thought.

Just spent the weekend at a preparation for cruisingseminar with John & Lyn Martin from the island cruising assocation of NZ in Mackay.

Interesting in their recent 6 month rally from NZ north to Lousiadies and back to Mackay they did 500 engine hours. Useful info regarding fuel to do ones planning. Area all prety similar to GBR/coral sea where have to do a lot of motor sailing in coral areas.

Cheers

John

[Lagoon4us]

Originally Posted by jff

Sorry I meant the 400ah, which they are selling for US$440 vs USD$1012 for the 700ah, freight needs to be added in both cases, and how much of a rush you are in

OK Winter will be the project timing so a month/6week delivery would not hurt at all. As it stands now i'm shortlisting the components hoping to use this threads knowledge to achieve a workable installation using a consensus.

Time for me to go through the last 4 pages of this thread and draw up a plan/spec for comment covering the different possibilities.....
Cheers

[Lagoon4us]

Trying to follow the issue of engine driven alternators charging these lithiums.
Is the issue that they accept a full rate of charge 'till chockers then suddenly cut the feed off which can be devastating to the alternators??

John pointed out a inverter charger running off the gen-set but we only have 6kva which restricts this option a bit once other loads are bought on.

Can the charge go through the engine start batteries which are lead acid bleeding power from them to the Lithiums maybe with a blocking diode preventing flow the other way i.e. Lithiums to lead acids??? Forgive me if this is dumb.....

Cheers

[Lagoon4us]

Are these an option to run one charger whilst motoring? Then the same charger by shore or genset???


http://www.meps.com/New_Site/Documen...ochure-kVA.pdf

[Lagoon4us]

With 4 x 195 watt solar panels would this controller (60amp) be usable?
http://www.lithiumion-batteries.com/...controller.php
Cheers

[ebaugh]

If the lithium bank is protected for over and under voltage by solenoids that automatically isolate the bank for those conditions, there will be one or two solenoids. Two solenoids with the right monitoring system can open the charge path for overvoltage and the discharge path for under voltage. If you only use a single solenoid, either case fully isolates the battery. The CellLog8 solution only has one output for alarm, so it has to be a single solenoid solution. You might be able to use two CellLog8 devices, one set for each condition.

If the solenoid opens for over voltage, and there are is no other battery in your system, it's just like moving a manual battery switch to the OFF position and can damage the alternators. And all of the house loads will lose power.

Not everyone uses solenoids, some just use alarms, or maybe not even any kind of monitoring. So they don't have this problem. But I think it's needed, one for an insurance policy saving the batteries, but also for safety reasons on overcharge. If you significantly overcharge them, they will heat up and vent, neither good.

[ebaugh]

Originally Posted by Lagoon4us

Can the charge go through the engine start batteries which are lead acid bleeding power from them to the Lithiums maybe with a blocking diode preventing flow the other way i.e. Lithiums to lead acids??? Forgive me if this is dumb.....

Cheers

Yes, that's what I have set up. I don't use a blocking diode, but you could. A normal isolator or better one of these:

http://www.amplepower.com/products/ccd/index.html

http://www.amplepower.com/apps/cross/index.html

[ebaugh]

Originally Posted by Lagoon4us

With 4 x 195 watt solar panels would this controller (60amp) be usable?
http://www.lithiumion-batteries.com/...controller.php
Cheers

You would think so....but I don't believe the company suggests the best charging parameters for LiFePO4. Too high a voltage. This is the FAQ from their website:

Alternator: Most alternators will sufficiently charge Smart Battery™ lithium ion technology.
Inverter: Most inverters have a way to set or program the charging voltage. Lithium ion batteries need to be charged as close to 14.4v - 14.6v as possible to get a full charge.
Standard charger: A standard battery charger will charge Smart Battery™ lithium ion technology due to our advanced built in battery management system.

Lithium Charger: Purchase a Smart Charger from Smart Battery™ specifically designed to charge our lithium ion batteries up to 14.6V

[ebaugh]

Originally Posted by Lagoon4us

With 4 x 195 watt solar panels would this controller (60amp) be usable?
http://www.lithiumion-batteries.com/...controller.php
Cheers

I like the MPPT controllers. Here are 3 options from Victron, Outback and Morningstar. I downloaded the manuals for all of them, and look like they can be programmed for lithium voltages:

http://www.victronenergy.com/upload/...0%20-%20EN.pdf

http://www.outbackpower.com/docman/2...Spec-Sheet.pdf

http://www.morningstarcorp.com/en/su...SMPPTdsEng.pdf

The other advantage is you will be able to put your panels in series and lower the size of the needed wiring. Might be 2S/2P or 4S depending on how everything specs out.

[ebaugh]

Originally Posted by Lagoon4us

Are these an option to run one charger whilst motoring? Then the same charger by shore or genset???

http://www.meps.com/New_Site/Documen...ochure-kVA.pdf

Yes that would work. Probably not inexpensive though. But it would also be a practical backup for your normal genset.

But....do you have the HP to spare? It's going to take 3-4 HP for each 100A of charge current.

[ebaugh]

Originally Posted by Lagoon4us

John pointed out a inverter charger running off the gen-set but we only have 6kva which restricts this option a bit once other loads are bought on.

The Victron Inverter Chargers can be programmed to load share. With the generator running on the boat, they can automatically add AC capacity to the boat system through the inverter, when the AC loads are below the generator capacity, it will automatically use the excess capacity to charge the DC battery system.

So this way, you don't have to manage the loads manually, it's automatic. It tries to keep the generator fully loaded, which is where they are most efficient.

[downunder]

Originally Posted by ebaugh

The Victron Inverter Chargers can be programmed to load share. With the generator running on the boat, they can automatically add AC capacity to the boat system through the inverter, when the AC loads are below the generator capacity, it will automatically use the excess capacity to charge the DC battery system.

So this way, you don't have to manage the loads manually, it's automatic. It tries to keep the generator fully loaded, which is where they are most efficient.

+1

Adding a Vitron inverter charger would give you reduncacy with your chargers and as ebaugh said they can be programmed for lithium. Check out Nick, S/V Jedi's system. Thats what he did. He would have good advise also. Try PM him if he is not at sea.