Battery chargers

I'm a new HAM and I'm looking for a little advice on battery chargers.  I have a 12v 7ah battery out of a Verizon Fios unit that I am looking to charge and use.  The battery is a few years old but I thought I might be able to get a little more use out of it before I commit to buying new.  I have seen several generic chargers on Amazon and Harbor Freight and am wondering if they are any good.

The goal is QRP with a mobile unit and battery when I go hiking.

What I have seen is 12v/6v chargers in the 0.75A - 1.0A range.  My understanding is that the more amps the quicker the charge.  Can anyone provide any recommendations on a decent charger? 

Robert / KC3LEZ

I use Deltran Battery Tenders.  The "Junior" model puts out 750 ma and it works fine for charging the typical 7ah batteries.  I had a failure of my Verizon power supply and it took them six months to replace it.  Meanwhile I stayed on line with a Battery Tender feeding the Verizon battery,  The Junior didn't quite keep up, so I bought a 1250 ma Battery Tender Plus, and it carried the load.  I still use them both to charge a bank of 7 ah SLA batteries, one at a time.  When I take a battery for portable power I just put the charger on the next one in line, and that works for me.  The Deltran chargers automatically switch to float mode.  I think the Junior is about $22.00 on Amazon, not bad, but I think I would spend the extra bucks for the 1250 ma Plus model.


OK, a 12v sealed lead acid battery 7.5 Ah.

Any automotive charger can be used to charge this.  However, it is best to "trickle charge the battery, that is, input current is limited to about 1/100 the ampere rating of the battery.  So, you would want to limit the charging to a .075 amp rate.  You can use a variable power supply with a current meter and just adjust the voltage til you get that going  into the battery.  A trickle charge can be left on overnight.

Now many of the automotive chargers are "automatic cutoff" and will charge-then trickle charge your battery.

Do you have an automotive charger yet?


-Mike. WA3SKN

The 442.300 KB3CMA Joint Repeater is off line since Tuesday 8 May while we replace it with the DR-2X machine, and make it play nicely with its controlled.  Hope to be back up this evening Thur 10 May.

The 442.300 KB3CMA Joint Repeater is back on line at 1445 Thur 10 May.  We replaced it with the the DR-2X machine, and it plays nicely with its controller as best as we can tell.  I don't see any immediate changes in the operation, but we should learn as we go.


- Gordon / WJ3K

This is not cheap, but it is very highly rated, versatile, and has served me well. It charges a wide range of batteries.

I use a Yeti 150 Portable Power Station. Definately not a cheap option, but it gives me the ablity to charge from vehicle, 110 current, or solar and provides 14Ah.  I can run my radios directly from it or use it to charge other devices.