LiFeYPo4 questions

[Mike90250]

.....Is it the lack of a BMS or just an incompatibility issue?

yes & partly

If you want the Li cells to last, each needs a BMS.

The charge controller will willingly pump out power and they regulate themselves by the voltage they sense. They have no way to interpret what the BMS system is trying to tell them.

I can use a custom programed controller to charge my NiFe bank, because the batteries are very forgiving. Li is not forgiving.

[DyslexicDancer]

Not going to work. LFP batteries are not compatible with charge controllers made for lead acid.

Well that's bad news, I thought I had read that it was possible with a MPPT charge controller that allowed you to set a custom charge profile, But to be honest I don't remember the Blog I was reading that talked about it.
Is it the lack of a BMS or just an incompatibility issue?

[Sunking]

Not going to work. LFP batteries are not compatible with charge controllers made for lead acid.

[DyslexicDancer]

I had a question for those of you in the know.

I want to experiment a little with LiFeYPo4 batteries for a solar off grid setup. Currently I use regular FLA batteries for a small back-up system, but I'm contemplating a much larger system for an off grid cabin and I want to do some research on LYP batteries because they seem like a much better option than FLA. If I can truly get 8000 Cycles at 50% DOD with a LYP battery, they would probably be cheaper in the long run then FLA

My plan is to get 4 100ah LiFeYPo4 batteries. The ones I’m looking at are these >http://www.alliancerenewableenergy.c...-LFP100AHA.htm

Next I plan on using a Morningstar TS-MPPT-60 charge controller with two 230 watt 24v panels. I don't expect much MPPT benefit other than the fact that the TS-MPPT-60 can be set to a custom charge setting and will down convert my panel's 24 volts to the battery bank's 12 volts, but what charge settings would I program into the TS-MPPT-60 for a LiFeYPo4 battery bank?

Next I have read that a BMS is not absolutely necessary if you Bottom Balance and only charge to 3.5 volts per cell, however none of the threads I have read actually cover how to bottom balance the battery bank. I assume I need a specific charger set up to charge one cell at a time (to a certain voltage?) and then a way to discharge each cell individually so that all the cells are at the same bottom voltage???? Any help on the proper way to bottom balance and what Items I will need to do it would be greatly appreciated.

Lastly I was planning on using a Celllog8s http://www.hobbyking.com/hobbyking/s...2_8S_Lipo.html to monitor the battery and a few Turnigy Watt meters http://www.hobbyking.com/hobbyking/s...dproduct=10080 to provide data on solar panel output (amps/volts), charge controller output (amps/volts) and one to act as battery out Amp meter. I have read that you cannot use battery voltage to measure SOC on a LYP battery and that you basically have to use an Amp counter to determine SOC