Three Battery Systems.....

[SilverLining]

Have finished adding an additional bilge pump to my 272 Sailfish(see Bilge Modifications thread)...now have two 2000 gph Rule pumps in the aft bilge and a 1500 gph Rule in the forward bilge as well as the shower sump pump.

Am now trying to decide how I want the three pumps set up to the battery system. Original G-W installation has a house and two starter batteries. Have added an ACR to the #1 starter battery leading to the house so that the house can be charged when the engines are running. G-W set up the original pumps with the forward bilge going to the house and the aft bilge going to the #1 starter battery. I have set up the new aft pump to the #2 battery(for now). I may add another battery beside the live well later(as per fishbust).

Obviously I can combine(both position on the switches) the two starter batteries, but am currently unable to use the house in conjunction with the starter batteries. Have always carried a jumper cable for emergency access to the house battery if needed.

Am currently considering replacing the off-on house switch with a "off-on-combine" switch(wired to the #1 starter battery so that I can have a combined bank of three batteries for all pumps in an emergency situation. Any thoughts on potential flaws/problems with this type of set-up???

 

[seasick]

Have finished adding an additional bilge pump to my 272 Sailfish(see Bilge Modifications thread)...now have two 2000 gph Rule pumps in the aft bilge and a 1500 gph Rule in the forward bilge as well as the shower sump pump.

Am now trying to decide how I want the three pumps set up to the battery system. Original G-W installation has a house and two starter batteries. Have added an ACR to the #1 starter battery leading to the house so that the house can be charged when the engines are running. G-W set up the original pumps with the forward bilge going to the house and the aft bilge going to the #1 starter battery. I have set up the new aft pump to the #2 battery(for now). I may add another battery beside the live well later(as per fishbust).

Obviously I can combine(both position on the switches) the two starter batteries, but am currently unable to use the house in conjunction with the starter batteries. Have always carried a jumper cable for emergency access to the house battery if needed.

Am currently considering replacing the off-on house switch with a "off-on-combine" switch(wired to the #1 starter battery so that I can have a combined bank of three batteries for all pumps in an emergency situation. Any thoughts on potential flaws/problems with this type of set-up???

I am not sure what charging isolation you have. The ACR may not have any and just be a relay. I would be cautious combining all batteries if the house battery is a different type, brand, model and age of battery. I would assume the house is a deep cycle type and the others are starting batteries. Each type has different charging and running characteristics and it is not advisable to run them paralleled.

 

[SilverLining]

Thanks seasick....points understood and well taken.

Not so much worried about normal charging since that is done on my lift with a 3 bank "smart charger". Charging by the twin motors gives about 35 amps at a increased rpm to each starter battery. The Blue Seas ACR is only there to allow the charging house battery by the S/B motor while charging the #1 starter battery when underway.

I can only envision combining all three batteries so as to provide the maximum "pumping time" for the bilge pumps during an "O Sh**!! situation. Can you foresee any drawbacks to using the batteries combined as described??

 

[fishbust]

You could add a 4th battery, 3rd batt switch and enable combining for all with a charge present without combining via switches. 1 house is not good enough, always need a backup plan.
You want to wire pumps to batts individually. If you combine and walk away, it will take only 1 stuck float switch to kill all the batts. Never want to put all your eggs in one basket.

 

[seasick]

Thanks seasick....points understood and well taken.

Not so much worried about normal charging since that is done on my lift with a 3 bank "smart charger". Charging by the twin motors gives about 35 amps at a increased rpm to each starter battery. The Blue Seas ACR is only there to allow the charging house battery by the S/B motor while charging the #1 starter battery when underway.

I can only envision combining all three batteries so as to provide the maximum "pumping time" for the bilge pumps during an "O Sh**!! situation. Can you foresee any drawbacks to using the batteries combined as described??

If you connect all three in parallel or the house and one of the starting batteries, they will charge whenever the motors are running. That is where you want all batteries to be the same.(including age)