Solar tending a 12v battery pack.

[Dave Shepard]

I'd like to have some 12v power near my mill to run a transfer pump on a fuel tank, and maybe a couple of small lights without having to start a 25kw genset. Has anybody here used a small solar array to tend a couple of 12v batteries, and what kind of batteries are best for this application? I'm thinking deep cycle, but maybe it's not that critical for my limited use. I also was thinking of using the two 12v batteries on the genset as the source and just keeping them topped off with the solar panel. The genset doesn't use a lot of juice to start, and I can hand crank it if I kill the batteries. :D

[POSTON WIDEHEAD]

Dave I have a 12v deep cycle battery I use for pumping diesel from my tank to my tractors. I only charge it once a year......and when I do, it's not low.
I think the solar idea is great. I may even do that. 

[sprucebunny]

I'm starting to add solar chargers to equipment at my woodlot where there is no power. The brand I've been getting (PulseTech) has a built in battery desulfator which makes the batteries last longer. They offer a 5 watt charger/panel ($120) and a 2 watt model ($70). Both are available at Walmatt online, haven't seen them in stores.
Here's a link to a place that has a large assortment of thier products.
http://www.impactbattery.com/brands/pulsetech/

[beenthere]

Sounds like a good idea.
I see on Amazon there is

35 Watt Solar Panel 12 Volt Battery Charger + Charge Controller in One Pack

for $120.

[ChopperDan]

It depends on how much power you want to use and how long it will take to recharge.

I currently have 80 watts to keep my 5th wheel battery's charged.

I bought 4, 20 watt panels on amazon for about 50 bucks each and a charge controller for 30
Charger controller
http://www.amazon.com/gp/product/B002GIWMJG/ref=oh_details_o06_s00_i00?ie=UTF8&psc=1

The lighting in the rig was also converted to led (brighter and less power)

Battery's should be deep cycle or fork truck are even better. I've been using 4, 100ah sla battery's for the past 3 years without issue. They were free.

The suns intensity will effect the output of the panel. So when the sun is at the strongest you'll get the max out of the panel. The output varies greatly over the day. In the winter I figure the capacity for the cell as the daily output. 80 watts total for the day. That just my rough guesstimate. I have a watt meter  connected and the best I have gotten has been 1000 watt over 7 days. That works out to about 140 watts a day. The panels also need to be angled and pointed in the correct position.

Here is a link about positioning solar panels
http://www.macslab.com/optsolar.html

Dan