Horsepower???

[Shawn]

I have two group 24 batteries on a typical battery switch along with an echo charger between them. Solar charge controller goes to first battery directly. The controller also has low voltage disconnect which the bilge pump is wired to. All loads and alternator go through battery switch except for fridge which is wired  to  second battery directly.

Any time first battery is receiving charge (solar or alt) the echo charger will divert up to 10 amps to the second battery to charge it up. If the fringe happened to run down the battery 2 I still have the main battery for other loads or starting the engine. Of course it could also be pull started if needed. I may move to a bigger bank later on but this is working well so far and allows for mismatched batteries.

Shawn

[Shawn]

I think the worst draw is really incandescent lighting. With cabin and nav lighting on I was pulling 5-6 amps. Led drastically reduced that to maybe a half amp with everything lit up. The dometic cf-25 is about 15 or 20 amp hours  per day. The 100w panel can handle that. The 40w I had on my 23 could not but it was enough to keep it running for quite a few days of a group 27 battery.

I will be adding autopilot, chartplotter and an espar heater. With those and the fridge I will likely need more. I have another 100w panel that I can mount on the rear rail next to the first. My charge controller is 20 amp so it would handle it easily.

If I ever refrigerated the ice chest I would likely need more power too.

Shawn

[Blown Away]

I have two group 24 batteries on a typical battery switch along with an echo charger between them. Solar charge controller goes to first battery directly. The controller also has low voltage disconnect which the bilge pump is wired to. All loads and alternator go through battery switch except for fridge which is wired  to  second battery directly.

Any time first battery is receiving charge (solar or alt) the echo charger will divert up to 10 amps to the second battery to charge it up. If the fringe happened to run down the battery 2 I still have the main battery for other loads or starting the engine. Of course it could also be pull started if needed. I may move to a bigger bank later on but this is working well so far and allows for mismatched batteries.

Shawn

I think the worst draw is really incandescent lighting. With cabin and nav lighting on I was pulling 5-6 amps. Led drastically reduced that to maybe a half amp with everything lit up. The dometic cf-25 is about 15 or 20 amp hours  per day. The 100w panel can handle that. The 40w I had on my 23 could not but it was enough to keep it running for quite a few days of a group 27 battery.

I will be adding autopilot, chartplotter and an espar heater. With those and the fridge I will likely need more. I have another 100w panel that I can mount on the rear rail next to the first. My charge controller is 20 amp so it would handle it easily.

If I ever refrigerated the ice chest I would likely need more power too.

Shawn

I totally agree incandescent lights are power pig's. Last year I installed all new led lighting on my little CP16. After tallying everything if I remember correctly I was under 0.25 amps with everything on at the same time. Believe it or not my battery bank consist of two little 12v 7.5Ah/20 deep cycle deer feeder batteries. I think both batteries and the charger combined cost less than 50  bucks. I haven't stayed out on her longer than one night so I can't honestly say that I have put this setup to the test. Is there some advantage to 6v batteries? I hear of more and more boaters switching to 6v systems so surely there has to be a reason.

[Shawn]

Boats are still 12v systems, they just use 6v batteries in series to get to 12v.

I believe 6v deep cycle batteries tend to be a little cheaper as they are very common for golf carts and electric wheelchairs and such. They are also true deep cycles that can be discharged deeper (and potentially more cycles) without issue compared to dual duty 12v batteries.

The other thing that is a bit different is charging as they will be in series vs a paralleled bank of 12v batteries.

A series charging bank (two 6vs) will keep the batteries voltages more in sync with each other and will also prevent overcharging a weaker battery. On the flip side that overcharge prevention could prevent the other battery from being fully charged.

A bank in parallel (2 12v)has the potential to overcharge one of the batteries. The two batteries voltages can also get out of sync with each other easier duty to battery aging or potentially different resistances in the wiring. That is why most charge controllers have an equalization period that intentionally overcharges every so often to keep a series bank voltages the same.

That is sort of the idea behind my way of handling the (2) 12v batteries in my boat. Originally they were simply battery 1 and 2 and I used 1 for everything with 2 being a reserve. I added the echo charger so that battery 2 would always be properly charged when battery 1 was receiving a charge. After pulling the inboard (and not needing to be sure I had starting power available, though it is nice to have) I rewired the always on fridge to the second battery so I would be distributing the load over two different banks and to exercise the second battery.. The combination of the alternator and solar controller properly recharges battery 1. The echo charger makes sure battery 2 is properly charged. The nice thing about this is battery 1 and 2 are not in parallel so I can replace either if needed and they do not need to be the same capacity.

Eventually, I may make battery 1 a bank of two 6v batteries and move the fridge back to that. Then maybe make battery 2 a small motorcycle battery that is still charged by the Echo charger. That would just be a reserve for power tilt and electric start on the outboard.

Shawn

[Blown Away]

Boats are still 12v systems, they just use 6v batteries in series to get to 12v.

I believe 6v deep cycle batteries tend to be a little cheaper as they are very common for golf carts and electric wheelchairs and such. They are also true deep cycles that can be discharged deeper (and potentially more cycles) without issue compared to dual duty 12v batteries.

The other thing that is a bit different is charging as they will be in series vs a paralleled bank of 12v batteries.

A series charging bank (two 6vs) will keep the batteries voltages more in sync with each other and will also prevent overcharging a weaker battery. On the flip side that overcharge prevention could prevent the other battery from being fully charged.

A bank in parallel (2 12v)has the potential to overcharge one of the batteries. The two batteries voltages can also get out of sync with each other easier duty to battery aging or potentially different resistances in the wiring. That is why most charge controllers have an equalization period that intentionally overcharges every so often to keep a series bank voltages the same.

That is sort of the idea behind my way of handling the (2) 12v batteries in my boat. Originally they were simply battery 1 and 2 and I used 1 for everything with 2 being a reserve. I added the echo charger so that battery 2 would always be properly charged when battery 1 was receiving a charge. After pulling the inboard (and not needing to be sure I had starting power available, though it is nice to have) I rewired the always on fridge to the second battery so I would be distributing the load over two different banks and to exercise the second battery.. The combination of the alternator and solar controller properly recharges battery 1. The echo charger makes sure battery 2 is properly charged. The nice thing about this is battery 1 and 2 are not in parallel so I can replace either if needed and they do not need to be the same capacity.

Eventually, I may make battery 1 a bank of two 6v batteries and move the fridge back to that. Then maybe make battery 2 a small motorcycle battery that is still charged by the Echo charger. That would just be a reserve for power tilt and electric start on the outboard.

Shawn

Shawn
I think I have a couple of 12v condensing units laying around the warehouse that got pulled out on restoration projects thru the years. To my knowledge they were working at the time of removal. Anyway if you cover shipping you are more than welcome to one should you decide to refrigerate your ice chest. I'll dig around to locate them and double check the compressor windings. The only problem is that I'm pretty sure they are R12 units. Don't think I have any evaporators but I'll check.

Karl