DC to DC -12 volt battery charger

[LAWNMOWERMAN]

Anyone else using one of these? http://www.powerstream.com/DCC.htm
I am using one in place of a battery isolator.I have 2-75amp hour agms

 

[pods8]

Anyone else using one of these? http://www.powerstream.com/DCC.htm
I am using one in place of a battery isolator.I have 2-75amp hour agms


Yes, I've got some posts on it near the tail end of my camper thread (see my sig).

 

[MakersTeleMark]

Curious why you didn't use this instead?

http://www.powerstream.com/DCC.htm

 

[LAWNMOWERMAN]

Curious why you didn't use this instead?

http://www.powerstream.com/DCC.htm



I am cornfused! That is what I used.Is there something I am missing?

 

[MakersTeleMark]

Sorry, wrong link:

http://www.powerstream.com/battery-isolator-solid-state.htm

 

[pods8]

Sorry, wrong link:

http://www.powerstream.com/battery-isolator-solid-state.htm


Your link is purely an isolator, the one he linked converts the voltage to stage charging (makes up for voltage drops and properly conditions your battery). Its limited to 7.5amps which is low for someone trying to quickly charge but in general works pretty well and by using the remote line off an ignition hot only line in your rig then you get isolation from the truck battery when the rig is off.

 

[LAWNMOWERMAN]

I like the idea of a solid-state isolator and I considered it. The charger was easy to wire up.I was able to mount it in the camper right near my batteries.
It has its own cooling fan and nifty multiple flashing LEDs!!!!!!Need I say more?
It was a little expensive but I think the pulse charge technology is pretty cool.My AGM batteries seem to like it too.

 

[fish more]

You might even look into marine on-board chargers. I mounted one on the wooden side just in front of the door to access the hold down for the camper. They are waterproof and mounting them on the outside provides cooling for the charger. The nice thing about these chargers are that most of them are for deep cycle batteries, also the rate of charge is great for AGM's. Most marine chargers are designed to charge AGM's and deep cycle batteries to the correct level, and not over charge, they also work as maintainers.

 

[pods8]

You might even look into marine on-board chargers. I mounted one on the wooden side just in front of the door to access the hold down for the camper. They are waterproof and mounting them on the outside provides cooling for the charger. The nice thing about these chargers are that most of them are for deep cycle batteries, also the rate of charge is great for AGM's. Most marine chargers are designed to charge AGM's and deep cycle batteries to the correct level, and not over charge, they also work as maintainers.


I think you're talking about an AC-DC charger above right?

We're talking about DC-DC smart chargers. When I was looking I only ran across two manufacturers of them (powerstream and a much more expensive one for 40A from promariner). If you know of something new please clue me in.

 

[MakersTeleMark]

I think he is referring to something like this, which I will be wiring in shortly:

http://bluesea.com/productdocs/7650

 

[pods8]

I think he is referring to something like this, which I will be wiring in shortly:

http://bluesea.com/productdocs/7650


If so I wouldn't call that a "charger", its just another type of isolation device.

What we're talking about above is a smart charger that alters the voltage profile to stage charge your batteries properly.

 

[K7MDL]

The automatic charging relays sense the voltage on the starting battery and when it is charged up (above 13.7VDC for example) connects the house battery and charges both. Shut the engine off, the start battery voltage falls towards its resting voltage, the relay opens at about 13.2VDC and the house battery can run down and not prevent you from starting your truck. Same goal as an isolator, but relays have little voltage drop and can run higher current for the dollar. Run a large size wire to minimize the voltage drop and relays are a good solution for recharging house batteries running down the road.

The DC-DC or AC-DC chargers can do more for you with the multiple voltage/current levels they can provide, or pulse waveforms. They boost the voltage when needed above the DC supply voltage which might be from a DC power supply at 13.2VDC fixed output, or a small size long wire from your truck system.

So I think the DC-DC solutions are of limited value when your supply voltage is very close to the alternator output voltage, for example in high current capable low voltage drop wire system. The alternator wil lprobably get you well into the 14VDC range. If you are getting your power off a #14GA battery charge wire at your bumper 7-circuit RV connector, then you have lots of voltage drop and low current. The boost charger will be very helpful to more completely, if not somewhat slowly, charge your house battery.

There are DC-DC boost units rated at 20-40amps for ham radio use that coudl be applied here. They are used to boost the battery voltage as it drops slowly under load. Radios do nto like low voltage. A battery may start out 12.6VDC and drop to 10.6VDC at full discharge. The booster keeps a regulated 13.8VDC. This allows the radio to run more efficiently and run longer as they may cease working at 11Volts or so, and draw more current as the voltage falls. They also likely have a low voltage warning and disconnect. MFJ is one manufacturer.

Another solution I use for my home radio installation (and on my motorcycle radio install at times) is a 12VDC power supply set to 14.7VDC connected to a West Mountain Radio Super PowerGate40S isolator and charger unit. It does not boost, but most AC to DC fixed output power supplies are adjustable. You set the voltage a bit higher to compensate for the diode isolator voltage drop (about .3-.6VDC depending on current) and also to give the builtin 4-stage charger the higher voltasge it needs at times.

The key to selection of the right solution is what your 12V source will be. Is it fixed output from an AC to DC power supply? Adjustable output voltage? The truck system? What voltage drop you will get.

Some alternate ideas for you.

- Mike

 

[LAWNMOWERMAN]

I am using my batteries to run a 12volt fridge(maybe 1.5-2 amps)and some led lights.What I like about my DC-DC charger is it is very kind to my expensive AGM batteries.My charger is powered directly from my truck battery with about 10ft. of 10 guage wire (as per oem).If my power demands were greater perhaps I would go some other route.As it stands I feel that my DC-DC charger is about as good as it gets compared to other alternitives.