Battery bank in 1988 32-200

[Peter K]

I have 2 group 27 Trojan AGMs in the original battery compartment below the mattress in the aft cabin. Each is a separate bank and I use the original 1, 2, All switch configuration. I am planning to add 2 more Group 27s and locate them in a battery box (need to build) in the bottom of the hanging locker (also in the aft cabin) with a connection to the original bank area. This will expand bank #1 to 3 group 27s and leave bank #2 with 1 group 27.

Has anyone put batteries in the bottom of the hanging locker on a 32-200? Any concerns?

Thanks!

Peter

 

[RHenegar]

187 e32 battery upgrade

Last year I upgraded my battery bank. I now have 2 group 31 house batteries combined in one bank and a separate group 27 starting battery on a separate bank in the same space under the aft bunk. I started by cutting the original fiberglass tube out. There was an amazing amount of wasted space. I built a new floor out of marine grade plywood and re-glassed the entire structure. I have a charge sensing component in the system that will charge both banks from either the alternator or shore charger, but keeps the starting battery isolated so it doesn't accidentally discharge. The battery combiner switch is still in place in case I ever actually need to join both banks. I have a LINK battery monitoring system so that I can keep track of everything. I had an electrician come in and wire to whole thing up because I wanted it done right. It works great.

I tried to attached the wiring diagram the electrician left me and some photos to show the results, but I am having a little trouble with this site. If it doesn't come through, I will try on a follow up post.

 

[RHenegar]

187 e32 battery upgrade additional info.

One other note on the my configuration. I don't ever have to mess with the battery switch. Because the starting battery is always isolated from the house load, but always connected to the starter, I don't have to use the switch to isolate it. Also when I complete the modification on the battery box, I found that 3 group 27 would fit side by side by side, but to put 2 group 31s in I had to set them in fore and aft.

One other note, when I started this project and was looking for space for batteries, I notice there was a flat surface on the starboard side of the engine compartment parallel to the prop shaft. It actually sit at the bottom of the starboard locker. Pull the panel off in the aft bunk and look directly across the prop shaft to see it. That was where I was going to put my starting battery.

 

[Tom Metzger]

I tried to attached the wiring diagram the electrician left me

View attachment 23198

It's a little hard to read the wiring diagram, but I am 99% sure it is not correct. Either the WD and/or the boat. The battery monitor isn't looking at the correct current. The only connections to the engine ground in this circuit should be the negative side of the shunt and the negative lead of the start battery. As I read it the house bank is connected to the engine ground at the shunt and not going through the shunt. I'm not home so can't make a drawing to show what I mean.

 

[RHenegar]

Tom,

Thanks for the feedback. All I know is the system works and has been doing so for the last 3 years. Awhile back I ran the house bank down below 12v using the autopilot, but the starter battery was still at 12.7. Started the engine and could see the house bank being recharged. Apparently the trick in the system is a voltage sensing relay that manages the charging. I am not an electrician, but had a highly recommended guy build this system. I asked him to do the drawing at the last minute so I suspect the drawing to be incorrect. You mentioned the house bank grounding, but I notice, or at least it appears to me, that the starter battery isn't grounded in the drawing as well. As I stated I am not an electrician. Electricity is a black art as far as I am concerned. I would like to get an accurate drawing for my records. Another thing on my to do list.