Date: Tue, 21 Dec 1999 08:55:15 -0800
Reply-To: Brent Christensen <bpchristensen1@HOME.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Brent Christensen <bpchristensen1@HOME.COM>
Subject: Re: What Size Inverter Do I Need?
In-Reply-To: <000601bf4980$ced6fa20$6d8a70d1@Kev.alaska.net>
Content-Type: text/plain; charset="iso-8859-1"
Kevin:
I have a pair of "wheelchair" type deep cycle gel batteries mounted in the
space under the driver's seat (about 62 aH total, I think) and I run ALL my
accessories off these batteries (except fridge), including a 300-watt
inverter that I got at West Marine (a relative "cheapie" which I am sure is
not as efficient as a $300 unit...). Anyway, I will typically run a couple
of laptops and maybe the stereo while parked. (My brother and I will sneak
away for weekends and work on business interspersed with a little Half-Life
over a crossover cable <g>)
Bottom line, I can run two laptops and the wimpy stereo for about 6 hours
off the aux battery before my LED runs into the "red". While this is hardly
scientific, (I have yet to actually take temperature and voltage
readings...) I have done this on about 6 or 7 occasions with no problems.
Another non-scientific tidbit: even with fully-charged batteries, the 300w
inverter is insufficient to run a Waring 10-spd blender to make margaritas -
it won't spin fast enough to crush the ice... :-(
BTW, Costco has the same 300w inverter as West Marine for about $35 right
now. (I think I paid close to $70 at WM).
Brent Christensen
'89 GL Syncro Westy "Klaus"
Santa Barbara, CA
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM]On Behalf
Of Turinsky
Sent: Saturday, December 18, 1999 9:54 AM
To: vanagon@GERRY.VANAGON.COM
Subject: What Size Inverter Do I Need?
Like many of you have already done, I'd like to install an onboard
electrical system for some interior lights, Propex heater, stereo, 'puter,
etc. all run off of an Optima battery.
The Optima battery rates at 52 amp/hrs. I've calculated my max daily
consumption at roughly 35 amp/hrs. According to West Marine you should have
at least 20% of your inverter's rating in amp-hrs of battery capacity.
Therefore, I come up with about a 300 watt inverter (20% of 300 watts = 60
amp/hrs. compared to the Optima's rating of 52 amp/hrs.).
West Marine says that this calculation roughly "allows you to run your
inverter for two hours at half power while consuming 50% of the battery's
energy." Huh? I don't get it. Is this overkill, or not enough? Can a 300
watt inverter handle lights, heater, stereo, and 'puter running all at the
same time for a few hours?
Now one of the ftp files I got off of gerry.vanagon.com says your battery
capacity should be double your expected daily amp/hrs. consumption.
According to this, I'd have to be driving around with 90 pounds of Optima
batteries, i.e. two Optimas! Yikes! And who has room for two Optimas?
I'd also like this setup to recharge itself as I'm motoring down the road.
I'm really flying blind here. I've just read enough to make myself
dangerous. Any guidance will be appreciated.
Hope you're all enjoying a big vat of figgy pudding.
Kevin
'89 Syncro Westie
"Anchored, down in Anchorage - Alaska"
