Re: (ET) Pack Monitor

[Markus Lorch <ev lorch net>]

John,

for the ETs I agree with you. These batteries are simple, the load is 
typically very low, they will last.
Its different when you either
1. use older batteries that you do not want to overdischarge
2. have a large yard that requires you to use most of your capacity 
(well battery capacity that is :)
3. or have an electric vehicle that draws high currents (when compared
to battery size) or requires the full capacity or both
in these cases it is crucial that you know exactly when the first 
battery in a pack is empty or full, otherwise the pack wont last.

For example I have 14 batteries that are about 1/10th the size of the
golf cart batteries powering a vehicle that has 10 times the rated
power of the ET. Basically these small batteries are delivering the
same current as the 10 times larger golf cart batteries. If one steps
out of the line, is empty early or, I have a problem. And if I have a 
problem while away from home, then its a bit more complicated than 
running an extension cord to the ET in the back yard. Hence here I
need monitoring.

For the basic ET user, its overkill. A battery monitor with full/empty
LEDs for each battery (a couple zener diodes, resistors and a dual color 
led) as Chris suggested 3 or 4 years ago is enough. Well thats my take.

Markus

john briese schrieb:
> I wonder what all the fuss is about monitoring batteries.
> I bought trojans, 6 years ago. Filled'em when I remembered. Mostly had 
> them on a landis charge controller. Really no special attention. They 
> have gone to a new home now and still have plenty of life, but even if 
> they were used up now, that would be $300/6=$50.00 per year. And at 
> today's price ? $600/6= $100.00 per year.
> How much longer am I going to get from them if they are treated like 
> queens and I throw everything at them?
> My point is keep it simple.
> John Briese
> still with one I-5
>
>
>
>
>  
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Elec-trak mailing list
> Elec-trak cosmos phy tufts edu
> https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak