Re: PTC protected dual battery harness

[Frank Olson <use_the_email_links@xxxxxxxxxxxxxxxxxxxxxx>]

Nomen Nescio wrote:
>> How much more "backup" does he need?  Most panels can handle recharging
>> up to a 14AH battery (2 7AH batteries in parallel will fit in most cans
>> if they're not "overloaded" with wire).
>
> Frank, when more than one battery is connected in parallel, the correct way
> to do it is to use some sort of overload protection in the battery leads.
> Either a circuit breaker, a PTC device, or even a properly selected fuse.
> Suppose one battery develops an internal short:  the good battery will
> start trying to charge the shorted battery, and hazardous amounts of
> current can flow.

I don't know whose batteries you've used, but "internal shorts" are
extremely rare.  DSC's 1864 has provision for connecting two batteries
in parallel (12v7AH).  There's no provision on the harness for an inline
fuse or PTC device.  Interesting.


>
> A comment on the original poster's question:  I think it is monumentally
> stupid for someone to take over 35 DMP panels (DMP's biggest and most
> powerful panel, by the way) and not have a source for spare parts.  If he
> can't even come up with a battery harness, what's he going to do when he
> needs a keypad or a loop expander, or when one of those XR500 panels craps
> out on Friday night?
>

Agreed.  But then there's always Jim R's garage...  :-)

Frank Olson
http://www.yoursecuritysource.com

"It only implies that I don't sit back and let you post more false
accusations without responding." -  Robert L. Bass