Pros and Cons on Different DC to DC Chargers

[Glennman]

I'm thinking about scrapping my Victron Orion battery combiner that I installed but haven't used and going with a DC to DC charger (or more than one). The main reason being that if the house batteries are real low, the alternator will work in overtime and pump enough juice to bring them back possibly at the expense of the alternator itself overheating.

So, I've been researching some various DC to DC units such as Sterling and Victron.

I've read a lot about the Victron units getting very hot. That doesn't sound very good and could be a cause of early failure. Also, the Victron units appear to be limited to 30 amps, where others are 40 and 50. I have ( Lithium Iron batteries with 3000 watts of solar, so maybe a 30-50 amp DC to DC unit is all I need.

Any discussion on this?

[buswarrior]

You are right to carefully protect the coach alternator from the voracious amp consuming potential of the lithium iron house batteries.

Are there units you are considering that let you throttle the amperage up and down?

The solar will still be charging while driving, so normally set the amps lower for a supplemental boost?

If the solar fails, then ramp up the unit and run the alternator harder to do the whole job?

Just spit balling...

Happy coaching!
Buswarrior

[Glennman]

Buswarrior, those are very interesting points. I don't know if anything like that exists. Maybe someone will weigh in on that too!!!

[luvrbus]

 A separate 1 wire alternator will regulate itself and takeout the electronic gizmos. The DC to DC chargers do get hot 

[Glennman]

A separate alternator is a good idea. That being said, I don't have any problem with actually installing one mechanically, but there must be some figuring on how to determine RPMs in relation to belt and pulley sizes. Any advice on how to figure that out?

[buswarrior]

Another alternator still doesn't stop the amp hungry lithium batteries from running it full tilt.

There needs to be a throttle on their appetite.

Happy coaching!
Buswarrior

[TomC]

I would get an inverter/charger. Mine puts out a maximum of 130amps. Good Luck, TomC

[dtcerrato]

I would get an inverter/charger. Mine puts out a maximum of 130amps. Good Luck, TomC

What Tom said. Our 2800W Magnum inverter charges at 125A or can be dialed down to any increment below the max amp output.

[luvrbus]

What Tom said. Our 2800W Magnum inverter charges at 125A or can be dialed down to any increment below the max amp output.

People are missing the point he wants charging while driving without generator use,a inverter charger needs AC current to charge

[oltrunt]

I use a Sterling battery to battery charger on my little bus.  The only time it seemed to be a little hot was on the first trip with it--just the "new" wearing off of it.  I put a switch in its circuit so it isn't trying to charge the house batteries while the alt is recharging the start batteries at the same time.  Once the start batteries are topped off I add the house battery load.

As a side note the reason I went with the Sterling was to thwart the Yosemite camp host gestapo's who got their knickers in a knot when I ran my nearly silent genny to charge the house batteries when dry camping.  Seems they were OK with the diesel motor idling.  Go figure.  Jack

[luvrbus]

It's not that hard to charge a system that has the same volts the expensive isolators have a capacitive voltage divider that stores and regulates the volts to the house batteries our Trek had one ,it would heat up since the design was to get rid of the excess voltage by heat,that is why they have all the cooling fins on the housing 

[luvrbus]

The inverter charger can be fed by the start batteries / engine alternator to charge the LiFePo batteries.

I have a Magnum inverter and total electric coach ,it will convert the DC to AC but the engine alternator supplies the DC and the charger does not work when the invertor is on from a DC source.Unless you have some special Magnum those are AC to DC chargers   

[windtrader]

I'm thinking about scrapping my Victron Orion battery combiner that I installed but haven't used and going with a DC to DC charger (or more than one). The main reason being that if the house batteries are real low, the alternator will work in overtime and pump enough juice to bring them back possibly at the expense of the alternator itself overheating.

So, I've been researching some various DC to DC units such as Sterling and Victron.

I've read a lot about the Victron units getting very hot. That doesn't sound very good and could be a cause of early failure. Also, the Victron units appear to be limited to 30 amps, where others are 40 and 50. I have ( Lithium Iron batteries with 3000 watts of solar, so maybe a 30-50 amp DC to DC unit is all I need.

Any discussion on this?

I've been following this for some time but honestly just what problem you are trying to solve eludes me. You have a start and a house battery. Solar panels and the alternator and a generator are energy sources. What's the reason for the combiner,etc.?

[dtcerrato]

I have a Magnum inverter and total electric coach ,it will convert the DC to AC but the engine alternator supplies the DC and the charger does not work when the invertor is on from a DC source.Unless you have some special Magnum those are AC to DC chargers

You are correct, my bad..

[TomC]

I have 3-100amp BattleBorn lithium iron deep cycle batteries. I also wired into the main batteries the "Battery Isolation Manager" available through Battleborn Batteries. I highly recommend this since my 160amp alternator charges the batteries during the drive just fine. It is a smart isolation switch. Good Luck, TomC