re: my homepower system
31 aug 2000
>...this is part of what my first rough draft looks like...
>8 ea surette battery - 4ks-21-p 1350 amp/20 hr rated
do you mean 1350 amp-hours at the 20 hour discharge rate?
>some design considerations ...
>enough capacity that, as the system ages, it should still run
>everything 15-20 years down the road. i'm trying to factor in
>both panel and battery degradation over time.
>my understanding where the batteries are concerned is that if i
>can keep the load within the 100hr rating, i can greatly extend
>their operational life (probably).
keeping them cool helps. maybe surette has a discharge lifetime (total
number of cycles) vs depth of discharge curve like trojan's, or specs
the maximum energy that can be stored in a battery over its lifetime.
>a question i've had ... how do you prevent cross charging in a
>series/parallel battery setup?
maybe you don't. what's wrong with a little of that?
>how do you prevent a single shorted cell from pulling down your
>entire stack? seems to me you need blocker diodes but i've never
>seen that discussed in this group ...
i wonder how these "blocker diodes" would be connected. we've talked
about electronic monitoring... you might consider a fuse or excessive
current indicator like this (in courier font) in the cross connects:
| shunt resistor |
|------*--------www---------*------| the "shunt resistor"
| | | | might be a couple of
--- --www------->|------ --- back-to-back power
_ led limit bicolor _ diodes in parallel.
| resistor led |