Need advice on battery

[WU9B]

I am considering the purchase of a pair of Interstate Marine/RV Deep Cycle (Group size 27DC) batteries to run a baby off grid 100 watt ham radio station. (100 watts only on transmit; 12 volt radio with one amp on receive and 18 amps or so on transmit. I would only transmit at part time even on a busy contest and usually the radio would never be used more that 10-12 hours even on a contest day)

I found these batteries at my local Costco. My research indicates that these are built by Johnson Controls which I believe makes a good battery. They have a 750MCA / 160 RC rating but I don see a KWH rating anywhere and I have checked their web site too. So I am wondering if anyone who reads this are familiar with these. Are they reliable? Is it OK to use these indoors in a well ventilated room? Should I bag that idea for a single AGM battery? I like the idea of having the battery (batteries) indoors as I live near Phoenix. I think I would remember be more diligent about checking fluid levels if they are indoors.

I plan on charging these batteries with 4 New Old Stock Photowatt panels PWX500 (17V@3 amps typical) using a Trace/Xantrex C40 charge controller. All of these components are in fine working order. I think this should run the radio and a few minor accessories and low voltage lighting just fine, even if I have a few cloudy days. (Any advice on lighting? 12v LCD/LED???? or whatever.)

Thanks for reading this and thanks in advance for your advice!

Steve WU9B

[Sunking]

WU9B this is Kf5LJW calling, QSL.

Your battery question is hard to answer because you did not list the model number for me to look up and reference too. Judging from what specs you did provide (MCA and RC) strongly indicates it is a hybrid battery and not a true deep cycle battery. Can you provide a web link?

I have a setup that will do what you want. In Phoenix area, what you want to do is for every 1 watt of solar panel, you want 1 amp hour of 12 volt battery. Take note your did not provide the Amp Hour rating of the battery in question. The reason is hybrid batteries will not specify Amp Hours most of the time and hence why it is not a true deep cycle battery. Trust me you want a true deep cycle battery for this application, not a marine hybrid.

Being mobile you are going to desire an AGM battery because they are sealed and will not leak. Avoid Gel batteries like the 11 meter Chicken Band. There many good manufactures for AGM like Trojan, Concord, Crown, and Deka. A good true deep cycle AGM is pricey but worth it for your application.

What I suggest is a 100 watt panel, 10 amp charge controller, and a 100 Amp Hour AGM battery. The battery alone will give you roughly 5 hours of dead key rag chew in a day, couple that with a good Phoenix Sun and a 100 watt panel and up that figure to 8 to 10 hours dead key. There is no way you can key up that long in a day without burning up your radio..

73's to you.

KF5LJW

EDIT note:

If this battery is just going to be used for field days and contest, I don't think you would need the solar panel. Use the savings (about $300 for a 100 watt panel and CC) to buy a really good battery and standard 3-stage AC charger. Just leave the battery on the charger at home. On field day throw it in the truck or car and go for it. A good 100 AH 12 volt model will last you all day and then some with a 100 watt HF transceiver operating SSB. I mean heck average power on SSB is 25 watts or less.

Just a thought.

[Naptown]

Thanks Dereck I knew you were in to the radio stuff

[Sunking]

Thanks Dereck I knew you were in to the radio stuff

You are welcome I do both Amateur and professional.

[WU9B]

Thanks for the replies. I already have the panels mounted where my old C Band Big Ugly Dish was. I already have the charge controller too.

The batteries being considered were the Interstate 517973. They are sold at Costco and are probably proprietary. The model doesn't show up on their web site http://www.interstatebatteries.com/cs_estore/ which is why I am asking. If they are not a true deep cycle (I don't know for sure yet) then the AGM advice from Sunking sounds reasonable... thanks... The search continues. Learning a lot and having fun too.

Steve WU9B

[Mike90250]

I'd say stick with the costco batteries for the first year. Most, if not everyone, ruins a set of batteries, best to do that with cheap batteries.