15 replies to this topic

[ri-f]

Rich,

 

Your Hawk for some reason [front dinette?] has a different battery box configuration than my '16 Hawk [side dinette]....there would be nowhere to truly vent the box in my Hawk although there is a small vent...it is a vertical box with a neoprene seal on lid in RF corner under dinette seat......did not know that Li batteries have less of a voltage drop at lower end of power range...I was also told that they charge quicker than AGMs....all in all LiFePo4 batteries sound like a wise choice...

 

Phil

 

Phil, we have a Hawk shell with left-side rear battery box in the lower part of the tower. But regardless of where your battery box is located, I still believe that you will not have an issue with heat dissapation if you have a well designed B2B charger that has a little room around it, that is, some air to breath. Even a modest amount of space around it would work. Also you could put a vent in the space you are going to install it in if you were overly concerned. Inside cabin temps in the height of summer are unlikely to get higher than the mid-90's F and the B2B charger is good to go, even in the low 100's F. Check the specs on your B2B charger to be sure.

 

Rich
 

[Vic Harder]

Rich/Phil, the Victron Orion B2B charger gets very hot.  It self regulates and limits charging to avoid heat death.  I have mine vented with a 45 cfm fan to keep that from happening.

[ri-f]

Rich/Phil, the Victron Orion B2B charger gets very hot.  It self regulates and limits charging to avoid heat death.  I have mine vented with a 45 cfm fan to keep that from happening.

Ah, didn't know that. Unfortunate. In that case, maybe the Victron Orion B2B charger wouldn't be the best option for installation in a space that had very limited air flow and couldn't dissipate heat well enough to avoid shutting down. The vent and fan is a good workaround, Vic. It's parasitic draw is probably minuscule. Tradeoffs are just inevitable. The Sterling B2B charger, from my experience, seemingly, isn't as temperamental as the Orion in small enclosures and hot weather. It will shut down if overheated, too, but maybe it doesn't get as hot as quickly as the Orion. It also has a built-in fan to dissipate heat through large vents, which is I suppose is similar in principle to what you did to compensate, by adding the 45 cfm. It's surprising because otherwise, Victron makes excellent equipment. Do you think that this was a design flaw?

 

Rich

 

[Vic Harder]

Design flaw?  Can't say.  It does get a lot hotter than their MPPT and AC/DC charger, all of which are passing 30A in my case.  The parasitic draw isn't a concern, as the fan only kicks on when the temp exceeds 40*C which likely means it is passing a lot of power through to the batteries.  

 

One thought, maybe my Orion gets hot because my truck has a "dumb" alternator, and 2g wiring, so it has to dump excess voltage down.  If the Orion is upping the voltage lost over long wiring runs on skinny wires from "smart" alternator, then it might not get as hot?

[ri-f]

One thought, maybe my Orion gets hot because my truck has a "dumb" alternator, and 2g wiring, so it has to dump excess voltage down.  If the Orion is upping the voltage lost over long wiring runs on skinny wires from "smart" alternator, then it might not get as hot?

Maybe. Mine has a dumb 120A alternator using 4 AWG, but the Sterling 1230 b2b is designed to never exceed 30 amps output. It typically starts out around 25 amps and drops over time with its 4-stage charger profile.  It's a slower charge rate, but it gets the job done. Probably easier on the components and maybe why I don't experience excessive heat buildup. Are you running a very high-output alternator?

 

Rich

[Vic Harder]

Just the stock 145A.