Re: Easy Service Call - Impressive Batteries

[ABLE1 <someone@xxxxxxxxxxx>]

On 8/7/2015 9:13 PM, Jim Rojas wrote:

>
> A few months back I started experimenting with Li-Mn batteries on my own
> security system.
>
> At the moment I have 2 banks of four 18650 2200ma Li-Mn batteries. It is
> roughly a 4AH setup at the moment. So far, no problems whatsoever. I did
> have to discharge the batteries down to 3 volts each so the security
> system would be able to charge them up to about 13.5 volts. So far, no
> problems at all. I still need to fully test backup time though. Since I
> am not over stressing the batteries at 3.7-4.2v, they should last a lot
> longer, and provide roughly 10 percent less of their overall rated
> capacity. This is something you just can't do with SLA batteries.
>
> I plan to add 2 more banks to give me a total of 8AH more or less. The
> nice thing about this setup is that it allows me to replace a single bad
> cell without tossing out the rest of the batteries. This is something I
> always disliked about SLA batteries. Sure I can buy Li-ion or Li-Mn
> battery for about $100 each, but then I have the same problem with them
> being sealed.
>
> I wouldn't recommend doing this out in the field, but it would be nice
> to see these type batteries used for security systems in the future at a
> much lower cost. I can see this battery bank lasting 6-8 years without
> any real issues.
>
> If all works as planned, I will encase the completed battery bank in a
> metal or plastic enclosure to minimize the possibility of a short circuit.
>
> Jim Rojas
>

Hi Jim, haven't see you around these here parts for a long time.  Hope
all is well in the "sunshine (among other things) state".

So now you had to put new input into my brain that forced me to Google
some stuff.  LiMn Lithium Manganese.  From what I have read they have
high amp short life or something like that.

I assume that you are using something like these.
http://www.smoktek.com/Efest-18650-Hybrid-IMR-Li-Mn-Battery--2200mAh-37V-button-top_p_862.html

Assuming that you are putting 3 batteries in a bank??
Then you have a voltage per bank of  3 = 11.1 to 12.6vdc

So what happens when you pull the AC from the panel??  How long do they
stay up before a low battery happens??

Interesting stuff.

Thanks,

Les