suitable charger

[Polishicebreaker]

Hi there, I'm looking for a suitable charger to charge 3 or 4 105ah batteries mainly from shore power but also from a generator if required.

Does this look ok ?

http://www.ebay.co.uk/itm/Sterling-Power-Pro-Charge-Ultra-12V-30A-Battery-Charger-PCU1230-3-OUT-/322033611775?hash=item4afab2f3ff:g:rs0AAOSwoBtW2Exn

 

regards Ed

[by'eck]

Yes and a good saving on r.r.p. The same company offer this 40 amp version as well.

[Alan de Enfield]

Check your generator has twice the 'wattage' needed by your proposed battery charger as some battery chargers have a Pf of as low as 0.6.

 

In theory a 40 amp charger should need 560 watts ( 40 x 14 volts worse case) in practice due to inneficiencies they can take almost twice as much.

 

Dont buy a little 500 / 600 watt generator if yiou plan a reasonable sized charger.

Check the output of your charger (continuous rating) not the maximum output.

[by'eck]

Check your generator has twice the 'wattage' needed by your proposed battery charger as some battery chargers have a Pf of as low as 0.6.

 

In theory a 40 amp charger should need 560 watts ( 40 x 14 volts worse case) in practice due to inneficiencies they can take almost twice as much.

 

Dont buy a little 500 / 600 watt generator if yiou plan a reasonable sized charger.

Check the output of your charger generator (continuous rating) not the maximum output.

[Alan de Enfield]

Thanks Ecky

Fingers going faster than the brain.

[dmr]

I am going to be controversial here.

From another thread you might know that our engine is broken and so I am charging the batteries from a dead cheap 700w generator that a forum member (mtb) lent me, and a 20 amp Halfords "Ring" charger that cost £75.

Our 20 amp Sterling charger (an old model) was not up to the job, not enough amps when hot, not enough volts, and wanting to go into float mode much too soon.

The main advantage (and also potential disadvantage), of clever boat chargers is that they go into float mode so can be left operating unattended long term. If you are willing to manually control the charge by monitoring current and turning the charger off yourself then some bog standard automotive chargers will do a good job (a better job) for a fraction of the price.

 

The Ring charger puts out 20amps when cold, maybe 13 to 14 when hot, and takes the batteries right up to 15v which is perfect for Trojans. Interestingly it was useless in battery charge mode but in "Engine Start" mode it works great.

 

.................Dave

[raymondh]

This may? be better and cheaper

 

Ray

 

http://www.ebay.co.uk/itm/Sterling-Power-Pro-Charge-Ultra-PCU1250-12V-50A-3-Way-Marine-Battery-Charger-/152027710835?hash=item23658ec573:g:jFQAAOSwZtJW9mH9

Edited March 28, 2016 by raymondh

[Loafer]

A 30A charger might be a little small for 420Ah of batteries.

 

A 40A one is about right, and the sterling Pro-Charge range allow you to prevent the early switch to float mode, so hated by offline-boaters.

 

That 50A eBay one would be good, if it works and goes for less than a new one.