DC to DC Chargers

Neil

Observer
My Victron B2B charger has fried itself, which is very disappointing as I had hardly used it

I have heard you guys talk about Renogy units but can't find a 24v to 24v unit.
Does such a unit exist or what are the alternatives available in North America

Thanks

Neil
 

VerMonsterRV

Gotta Be Nuts
Well that sorta sucks. I just pulled out a half dead Sterling B2B and replaced it with 2 Victron B2B's in parallel in hopes of having something a bit more reliable as this was our second Sterling that had failed. I think Redarc and Votronic make a 24 to 24 charger. Shipping from Europe into the USA is usually pretty fast and not too expensive, especially from the UK.
 

Geo.Lander

Active member
My Victron B2B charger has fried itself, which is very disappointing as I had hardly used it

I have heard you guys talk about Renogy units but can't find a 24v to 24v unit.
Does such a unit exist or what are the alternatives available in North America

Thanks

Neil
Warranty? I hear those units run hot...
 

DiploStrat

Expedition Leader
I use REDARC - small and no fan needed. Sterling Power also make units that will do 24v - more options in size and programming.
 

Joe917

Explorer

DiploStrat

Expedition Leader
B2B can't hurt, but you are never going to drive long enough to need to really worry about a multi-stage charge.

Proper profile is, however, critical for solar or shore power.
 

Iain_U1250

Explorer
You need a charge regulator/controller if you are charging lithium batteries..
I have been running my Lithium system directly off my two alternators for more than a year now.

I did a whole series of tests when I swapped over to lithium

I later swapped the 120A alternator for a 250A alternator with a standard 14.5V regulator.
We have done about 2500km with them, and no problems.

I reprogrammed my Solar controllar for Lithium as well, set them 14.3V max charge, the only thing I changed was the 240V charger, as the one I had started with a desulphination cycle which is not good for the LiFePO4 batteries, so I got a Victron on that was compatible.

I even run a LiPo starter battery, which is only connected to the starter, and it's own 90A alternator. Pretty impressed by that as it can turn the motor over really fast and weighs about 8kg only, it lives under the driver's seat now.




 
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Geo.Lander

Active member
I have been running my Lithium system directly off my two alternators for more than a year now.

I did a whole series of tests when I swapped over to lithium

I later swapped the 120A alternator for a 250A alternator with a standard 14.5V regulator.
We have done about 2500km with them, and no problems.

I reprogrammed my Solar controllar for Lithium as well, set them 14.3V max charge, the only thing I changed was the 240V charger, as the one I had started with a desulphination cycle which is not good for the LiFePO4 batteries, so I got a Victron on that was compatible.

I even run a LiPo starter battery, which is only connected to the starter, and it's own 90A alternator. Pretty impressed by that as it can turn the motor over really fast and weighs about 8kg only, it lives under the driver's seat now.




Nice, but lifpo4 will as you kmow pull most of the times 1C charging (or more) if not regulated. Which will fry most people alternators, so I would not recommend giving this advice to anybody that has not matched their alternator output to their battery absorption profile. Even so, using elastic 4 stage charging is generally recommended for lithium batteries, and also GEL batteries if you follow the datasheet above it explains why...

Best case scenario you are damaging your cells.
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Neil

Observer
I think Gel , Led Acid or Agm are a different animal to Lithium and they need the charging current regulated down to protect the batteries and charge them correctly .

Neil
 
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