Battery Charging

[pearley]

A couple of days ago the mains transfer switch in my Victron Multi-Plus failed so it is no longer charging the batteries from the shoreline. We are leaving the boat on Thursday for 10 days and want to leave the freezer on so need to keep the batteries charged enough for this. I've put a Smart charger on them but, it is too smart and shuts down after 24 hours with a fault code displayed which because the battery hasn't gone into float mode after 24 hours.

 

If I bought a cheap 2 amp charger and left that on for the 12 days am I likely to cause any problems? With a 540 amp battery bank that is having a 16 amp load every few hours I would think not but what do others think.

 

Regards

Pete

Edited September 25, 2012 by pearley

[blodger]

A couple of days ago the mains transfer switch in my Victron Multi-Plus failed so it is no longer charging the batteries from the shoreline. We are leaving the boat on Thursday for 10 days and want to leave the freezer on so need to keep the batteries charged enough for this. I've put a Smart charger on them but, it is too smart and shuts down after 24 hours with a fault code displayed which because the battery hasn't gone into float mode after 24 hours.

 

If I bought a cheap 2 amp charger and left that on for the 12 days am I likely to cause any problems? With a 540 amp battery bank that is having a 16 amp load every few hours I would think not but what do others think.

 

Regards

Pete

Ab 110 ah battery can stand a 1/2 amp continuous trickle charge without problems. So I would say you have your sums right.

[Arthur Brown]

If the batteries start off fully charged then I suspect that you will survive. DO you have a realistic and seasonally adjusted duty cycle for the fridge motor? If it draws 16A then a 2A charger will cope if the duty cycle is less than 12.5%, and IMO that's possible but probably on the low side.

 

Personally I'd expect your batteries to lose some SoC with the freezer on and a 2A charger alone to cover the consumption.

 

16 x 24 x 10 is total consumption =3840 AH

2 x 24 x 10 is charger input.... =480

 

Therefore a duty cycle of 12.5% will be covered.

 

If the duty cycle is more than this the battery SoC will fall mover the period.

 

Maybe a better solution is a bigger charger, 4amps would cover a lot more and maybe have some later use, an even better solution is an ebay constant voltage power supply set for 13.6V (WWIII may start over the last significant figure!).

 

/350472906779 on ebay set to 13.5v would be a superb constant voltage float unit. See the seller's other items for psu's up to 100A (which may be OTT but a super little float unit for a liveaboard.

[ditchcrawler]

A couple of days ago the mains transfer switch in my Victron Multi-Plus failed so it is no longer charging the batteries from the shoreline. We are leaving the boat on Thursday for 10 days and want to leave the freezer on so need to keep the batteries charged enough for this. I've put a Smart charger on them but, it is too smart and shuts down after 24 hours with a fault code displayed which because the battery hasn't gone into float mode after 24 hours.

 

If I bought a cheap 2 amp charger and left that on for the 12 days am I likely to cause any problems? With a 540 amp battery bank that is having a 16 amp load every few hours I would think not but what do others think.

 

Regards

Pete

Is this a 12 or 230 volt freezer?

[pearley]

Is this a 12 or 230 volt freezer?

If it was 230v it wouldn't be a problem as I've bypassed the inverter/charger by joining the mains input to the mains output.

 

Getting something from ebay not an option as we leave tomorrow!

 

Leaving the smart charger on overnight took the SoC from 90% to 91% so a 2 amp charger ought to cover it OK without excessive gassing.

 

Regards

Pete

[blodger]

If it was 230v it wouldn't be a problem as I've bypassed the inverter/charger by joining the mains input to the mains output.

 

Getting something from ebay not an option as we leave tomorrow!

 

Leaving the smart charger on overnight took the SoC from 90% to 91% so a 2 amp charger ought to cover it OK without excessive gassing.

 

Regards

Pete

Others are worrying not so much about the gassing as about ensuring the energy used is replaced.

As buy a cheapo 2 amp car charger why not put the money towards a better 10/20amp three stage charger that will be of more future benefit but make sure it is not too smart

[pearley]

Others are worrying not so much about the gassing as about ensuring the energy used is replaced.

As buy a cheapo 2 amp car charger why not put the money towards a better 10/20amp three stage charger that will be of more future benefit but make sure it is not too smart

If Victron are true to their words, the repaired unit should be waiting when we get back from Italy.

 

My wife has said 'sod it', she'll just empty the freezer and sleep soundly!

 

Regards

Pete

[gaggle]

Seen SMART charger so can i ask if this http://www.ebay.co.uk/itm/Ring-12v-Car-Van-Battery-Charger-SmartCharge-16-RSC516-/270817649868?pt=UK_Diagnostic_Tools_Equipment&hash=item3f0dfd64cc is the kind of charger that i could use now and again on the boat , this model says up to 200amp and as i have four batteries do i need another model that can deal with 400amp bank , i can not find 400 amp model today although i am sure i found one online last week after a couple of boaters told me to look for RING 16 CHARGER .

CHEERS.

[blodger]

Seen SMART charger so can i ask if this http://www.ebay.co.uk/itm/Ring-12v-Car-Van-Battery-Charger-SmartCharge-16-RSC516-/270817649868?pt=UK_Diagnostic_Tools_Equipment&hash=item3f0dfd64cc is the kind of charger that i could use now and again on the boat , this model says up to 200amp and as i have four batteries do i need another model that can deal with 400amp bank , i can not find 400 amp model today although i am sure i found one online last week after a couple of boaters told me to look for RING 16 CHARGER .

CHEERS.

Automotive chargers do nor expect to see large capacity banks and the SMART bit is not so clever as they can decide there is a fault because the voltage rise is not quick enough so they shut down. So you want a marine charger or a bog standard three stage charger that will go on to float and still be trickle charging; Others will be along with their recommendations