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

[T1 Terry]

On the first conditioning charge they are quite often a long way appart, once they are condition charged and balanced the problem rarely reoccurs. Remember, one cell only has to reach the 3.5v mark before the others and the voltage on that cell will rapidly climb. The real difference would be 3.3v to 3.45v, the rest is just surface charge, but it does make for a major problem if the charging relies on combined cell voltage alone without monitoring cell voltage.

T1 Terry

[electric1]

Originally Posted by witzgall

What to think???

Chris

I don't know what the deal is with your Celllog, I never use these myself, so I can't comment on its quirks. Based on your reported cell voltages at the end of charge, it seems your pack is well balanced and there aren't any real issues.

[T1 Terry]

If the cell logger is reading directly off the cells now, at the terminals, measure the voltage across those terminal with a good known to be accurate multimeter. It the logger reads a little bit different, like the 3rd decimal place, this can be fine tuned in the cell logger itself, if the voltages are way off, check all the connections first, it's most likely a high resistance joint.
Nothing else can be connected to the cell logger wires, it will effect the readings of 2 adjacent cells if any load is placed on any of the wires.
The Junsi cell loggers are very reliable and can take a far degree of punishment, they have to be able to handle flying in the model planes and in the race boats. They are very popular with the electric bike people and a rather cluey EV guy has made boards for mounting 4 loggers at a time with linking alarm port take off points etc. Many of the EV people are moving away from the active balancing BMS units and switching to alarm monitoring cell voltages only and letting their brains do the decision making.

T1 Terry

[ColdEH]

Just had the guys at Eco-Tech alternators change the set point on my Eco-Tech alternator to 13.8 volts . These guys are great to deal with , any body looking for the best alternator charging solution should take a look at there's . I will be getting close to 300 amps at 13.8 volts at an incredible 1800 RPMs . That told me they have some of there customers running these things 24/7 for the past two years . Wow !

High Amp Alternator, low RPM alternator, performance alternator, vehicle high efficiency alternator

Regards

[Jd1]

How does Lithium Iron Magnesium Phosphate compare to the standard LiFePo4 that is always mentioned ?

[Jd1]

Originally Posted by typhoon

Just had the guys at Eco-Tech alternators change the set point on my Eco-Tech alternator to 13.8 volts . These guys are great to deal with , any body looking for the best alternator charging solution should take a look at there's . I will be getting close to 300 amps at 13.8 volts at an incredible 1800 RPMs . That told me they have some of there customers running these things 24/7 for the past two years . Wow !

High Amp Alternator, low RPM alternator, performance alternator, vehicle high efficiency alternator

Regards

Would you happen to know the horsepower required to drive this alternator when there is very little or no current draw? I am wondering if this unit can be driven with a small 35 hp engine without affecting boat speed under power. Of course boat speed is affected when the alternator generates a lot of power but what happens when the batteries are fully charged and you only draw maybe 10 A or so?

[deckofficer]

Even at 300 amps, the pull is only around 6 hp.

[s/v Jedi]

Originally Posted by deckofficer

Even at 300 amps, the pull is only around 6 hp.

Sounds good, I am at 7hp for 385 amps with dual Lestek 220A alternators.

cheers,
Nick.

[senormechanico]

Theoretically, the HP draw should only be frictional bearing losses if the alternator is not charging.

Practically speaking, I wouldn't expect significantly more loss than you would get from a smaller alternator when it's not delivering anything more than a float charging load.

[Jd1]

Sounds good, I will need to see what is required to marry that unit to my engine ....

[T1 Terry]

I remember looking at those alternators when you mentioned them before, very nice bits of gear. The dump load protection sounds interesting, do they expand on what they term "dump load" at all? I'm just trying to find ou if they mean the load being dumped to a resistor bank or the load being disconected from the alternator while it's running.

T1 Terry

[ColdEH]

Originally Posted by T1 Terry

I remember looking at those alternators when you mentioned them before, very nice bits of gear. The dump load protection sounds interesting, do they expand on what they term "dump load" at all? I'm just trying to find ou if they mean the load being dumped to a resistor bank or the load being disconected from the alternator while it's running.

T1 Terry

Hey Terry , you should send them an email about that , ask Malcolm , I think he designed the alternator, they are very fast in answering any questions and even pick up the phone LOL.

They emailed me the complete service manual , just to make sure I got the removal of the regulator right .

This is Malcolm's email at Eco Tech.

mlombard@ecoair.com

[T1 Terry]

I will post the reply.

T1 Terry

[goboatingnow]

does anyone do stock alternators in high capacities that have the Diodes external ( and the regulator as well obviously). Id like to buy alternators without any electronics onboard

Dave

[CharlieJ]

Dave-
I have been down this road. I have only been able to find two mfgr's of alternators that mount the diode pack off of the machine:

• Electrodyne Div. of Gauss Corp.
  1 Gibson Rd.
  P.O. Box 660
  Scarborough, ME 04070
  Phone: 207-883-4121
  800-341-0242 (toll free)
  Fax: 207-883-442

• Polar DC Marine Polar DC Marine

The Daschew's have been using the Electrodyne product for years and rave about their durability. I have not been able to find a functioning website for them.

I have had contact with Polar DC Marine and have had some issues with clear communication with them. I have seen Polar's products at IBEX 2011 and was very impressed.