batteies

StirCrazy wrote:

otrfun wrote:
It's a common fallacy that a so-called "Lithium/Lifepo4 Approved" converter must be used to charge Lifepo4 batteries. Absolutely, not true. I posted this in another thread:

. . . arguably one of the better general-purpose, non-programmable charging platforms for a lifepo4 (as long as no charge/equalization mode exceeds 14.6v) is a 3-stage *lead-cell* 13.2v/13.6v/14.4v converter. It even has the advantage of a 13.2v float and more conservative 14.4v bulk vs. some of the 2-stage 13.6v/14.6v Lithium/Lifepo4 Approved converters.

. . . there will always be some debate about the best float/absorption/bulk voltages to use with a multi-stage converter to best charge a lifepo4. However, you'd be hard-pressed to find much debate about the best one, single voltage to both float and bulk charge a lifepo4. Why? Because such a voltage simply does not exist. This is why a single-stage (single/one voltage) 14.6v converter (even though Lithium/Lifepo4 Approved) is the worst possible charging platform for a lifepo4.

Claims that a given converter/charger is "Lithium/Lifepo4 Approved" are simply marketing ploys which tell you absolutely nothing about how well or safely it will charge and maintain your lifepo4 battery. The number of stages, and the voltage used by a converter to support each of these stages, ultimately determines how well a given converter will properly maintain (and charge) a lifepo4 battery.

I don't think it is absolutely true, in fact I agree that you can get by without one but should you... I think you can but only long enough till you can figure out exactly what you need then do the switchover. There are going to be some things you can't do properly without a constant voltage that is high enough, but here is my switch up. If you have enough solar, and your solar capacity is large enough to keep everything charged, then who cares about the charger on the converter... turn the breaker off, you don't need it. Then later when you decide you want to spend money you can change it out.

People seem to get hung up on this, but really, it's a couple hundred dollars, you're spending a couple K on batteries is it really a stretch to get a proper converter for them?

I look at this more as what do I need to get the maximum life out of that battery. I don't care if it will last for 15 years, I want 20 out of it. but when I was first looking into getting LI batteries most manufactures were saying to run your converter on a "Gell" setting as it is closest to a LI profile until you get a proper charger.

StirCrazy, you completely missed my point.

My post mentions specific "numbers" to look for when choosing the best converter to charge your lifepo4. Things like number of stages (1-3) and specific voltages (13.2v/13.6v/14.4v/14.6v).

If the goal here is to truly help someone choose the "best" converter for charging their lifepo4 battery, these "numbers" must be discussed. A "Lithium/Lifepo4 Approved" sticker or marketing claim means little to nothing. Outside of your claim that one must use a "constant voltage that is high enough", you offer nothing that would help someone choose the "best", or as you put-it, "proper" converter.

Here are voltage and stage specs for the most commonly available, off-the-shelf, RV converters:

14.6v one (single) stage converter
13.6v/14.6v two stage converter
13.2v/13.6v/14.4v three stage converter

Clearly, one of these converters has numbers that do a much better job of "pampering" a 12v lifepo4 than the other two. Care to guess which one it is?