NiMH vs. AGM Cells

[Adonyx]

You are preaching to the choir.

I've always thought that was an odd expression since the choir is generally made up of individuals who follow the teachings of the preacher and therefore have a need & want of his continued preachings, necessitating that he preach to them, while the expression itself is meant to imply that ones preaching is not necessary. :/

I only chimed in to clear up some details for people who are close to knowing how things work, and tragically limiting their potential through a slight misinterpretation.

With the critical need for power innovations that we are, and will continue to be faced with, it is IMPERATIVE that creative minds that aspire to improve alternative energy methods get the information that they need, and it's the responsibility of anyone who has it to find the people that need it.

[russ]

We appreciate your detailed descriptions - I am one of the ones who really needs to understand more.

It is a complex subject - especially for me

Russ

[Sunking]

As for the charging algorithm, that's not true at all.

No sir it is completely true as you outlined negative Delta V bump. There are no solar charge controllers on the market to do that to my knowledge, posible for the RC market, but none for the RE market. That is a completely different algorithm than lead acid or lithium technology which was my point.

[jestronix]

Ive been seriously considering setting up a 90AH LiFeP04 for solar, average daily use on my system is 60 amp hours. You can buy single cell 12v batteries (no need for cell equalization or BMS) , looking at thundersky ones. They have a cycle life of 5000 to 70%.

Plan is to use the thundersky for soaking up the daily cycle and a second bank of cheap batteries in basically a standby state, this way there are only ever cycled on cloudy days. Ideally two 90AH thundersky batteries should soak up most days with a day to spare, Id have to find out how many days are more than 2 days per year to get an idea.

Cheap batteries with maybe 40 cycles a year at 50% depth cycle could last quiet some time. This could work out cheaper than buying a large bank of high quality cells.

LiFeP04 technology allows for some nice discharge rates too.

Id need a dual charge setup with some tricks to do it, but here in Australia we do get a heap of sunny days so it could work. I wonder how long T105 trojans would last if they were only cycled 30 times a year to half depth? equalized of course. Would they sulfate from lack of use ?

The cost of having two controllers and the smarts to make it work may outweigh the cost benefit of course, however it could work.