I have a marine deep cycle battery I run a 2 meter radio on for use during power outages and storms.  I bought a cheapo battery charger from Wal-Mart to keep it up to snuff.  I've been using it for a few weeks and it works fine and keeps the battery on float after it brings it up to full charge.  The only problem I've seen is a little bit of hash on my HF rig when it's plugged in.  Otherwise you can't beat it for the price.  It was $26.00.

link

A word of warning: I charge the battery indoors because I like to live on the edge.  It never enters bulk charge because I never let it get low so i'm not worried about outgassing from the battery.  I won't bulk charge the battery indoors after a power outage because I may blow my ass sky high.  You shouldn't either!  

argh-a week late!  I picked up This unit at Academy Sports last week for $19...(hope it works as well as yours!!)

I have one by the same company, but it is a 1.5 amp trickle and float charger. I use it to keep the 2 18AH gel cells charged. I used it for years before to charge my deep cycle battery up and running when I did astrophotography. It works good, but would be afraid of using the charger while using the radio. The chargers will usually have some AC in them also, this could be the cause of the noise, much like an alternator on a vehicle, there is usually some AC that passes the rectifier.

I would not worry so much about the trickle charger in the house, although not advisable. I have been on the receiving end of a battery that gassed and exploded, it was truly an amazing sight, and very loud. Were were lucky since the rapid charger had a blast cage, it contained most of the acid that was expelled but it did blow the whole cart apart. The intelligent charger was beeping after the explosion " Bad Cell " Most of the time when you have a battery explosion because of gassing is when the battery charger has built it load testers, the gassed build during charging and the load kicks in, poor connection causes a spark and BOOM.

One of the reasons I do like the AGM batteries. I got my 2 AGM batteries from automotive jump boxes. Usually when the jump boxes will no longer take a charge it is due to the charger and not the battery. Both of the ones I got they thought the jump box was bad and were going to throw them out. So I pulled the batteries and charged them with the trickle charger and they work fine.

This is the one that I have http://www.batterychargers.com/ProductDetail.aspx?ProductName=94026717

I have a 12v Walmart lawnmower battery hooked up to a small 8" x 8" solar panel meant for a deer feeder. We use it intermittently to run a pesticide sprayer on a daily basis (it's the same kind they mount on a 4 wheeler except we don't have a 4 wheeler). We keep it in an outbuilding and spray plants as we bring them through in trays.

I'm going on 5+ months now, so far, no dead battery. We never run it into the dirt, so that probably helps.

Actually, I'm kind of surprised it has lasted this long.

i have that same charger but be warned, it will not take a battery up to what would be considered "full charge". look in the manual and you will see it only charges to just over 12.xx volts. fully charged a battery should be at 13.4-14X volts. most radios are designed to work at 13.8v +- 10-15%.

Mine brings my battery up to charge, but at the price I wouldn't be surprised if quality control is a problem.  

A fully charged 12v automotive or marine type battery will settle out at 12.6 volts. 2.1 volts per cell.

the charger wont take it high enough. let me hunt down the manual and i will see what voltage the charger shuts off at.

the manual says 12.8v or above and battery is charged. the problem is every time i have used the charger it stops charging between 12.6 and 12.8v then settles to about 12.2v doesnt matter if i use the 2a 4a or 6a setting. i will charge up the battery again on sunday and test it once the charger shuts off just to confirm but i have had to use a 15v 500mah charger to top the battery off. i need to pick up a deep cell battery for extended ops and yes, the damn thing is noisy on HF even when its plugged in and not even connected to the battery just close to the radio.

I'm a n00b at all this, so got to ask the dumb question here.
Similar to this one?

- or -
or this 12V Model SP12V1 ?

After it's been disconnected from the charger for a few hours, the battery's resting voltage will be around 12.6 volts. However, the voltage applied to the battery while it is being recharged needs to be considerably higher (i.e., 14.2 to 14.5 volts) - Otherwise, the battery never reaches a full state of charge.

Looks like the first one except for the connector. Mine just had two wires. I need to put a meter on the battery today and see where it's at.

Correct. I think mylt has a bum charger..

I left my meter at home, so I borrowed my Dad's meter (not autoranging) and it was showing 013 volts. It's been cloudy the last 2 days. Like I said, I'm surprised. I think that panel is $20 to $25 at Academy.

I don't think it would hold up and recharge if you ran it a couple of hours everyday, but for backup use, I think there's some possibility there.

I'm not following you, are you talking about charging the battery with a generator?

No, probably not, but you're not leaving a battery charger plugged in all the time either. Trickle charge off the solar. Then if SHTF, recharge off a generator and standard charger.

Ok, I see what you mean.  That's what I thought.  If I ever need to do that, I'm hooking the battery up to my car with an isolator. Running an AC generator to power an AC input battery charger to charge a battery (DC) would make for a lot of loss.  In fact you'd probably be so much better off with a redneck battery charger (lawnmower engine and old alternator) that it would be worth building it rather than trying to do it with a gen set.  

Here's one a guy built, and for a redneck battery charger it looks pretty slick!

video

I'm thinking charging the battery with an alternator run by a gas engine would be a lot more efficient than running a battery charger with a gen set but I'd have to test it to be sure.

Marine "Deep Cycle" batteries are usually a hybrid starting / deep cycle battery with medium thickness plates.

The best battery you can use?

Order a TRUE deep cycle battery.

You can get a ~100 ah Trojan deep cycle battery for under $200.

The Trojan SCS200 which is a 115 ah battery for $199 will give you 200 minutes of life @ 25 amps.  Most modern 100w transceivers draw approximately 20-25 amps during TX, so that's 200 minutes of talk time during a disaster.

Couple this system with a 100w+ solar panel and charge controller, and you've got electricity for a loonngg time.  

Typical transmit:receive duty cycle is around 10-20 percent. Most folks do a LOT more listening than transmitting!

Also, the 25 amps only occurs during voice peaks - The average current draw while you're transmitting is usually quite a bit lower.