Replacing Old Pathmaker 100/3

[cardminger]

Our boat has a Pathmaker 100/3 that seems to not be functional any longer. I have heard lots of stories about these units so I'm surprised it made it this far.


We are barely learning regarding the electronics on the boat but this step should be an education for sure!


What are your recommendations on replacements for this? Is a ACR from Blue Sea the way to go? It doesn't seem like it would do the same thing?


A bit more info on our setup:


The boat has 3 banks of batteries, 2 separate "house" banks and one engine cranking battery.


My understanding is that the goal of the existing pathmaker is essentially to isolate the engine battery from the house batteries when we are at sea, or without shore power and not running the engine or generator (effectively when there is a negative draw) so that we can't run down the engine start battery using our lights, electronics etc.


How can I replicate that functionality with a slightly more modern, fault tolerant system?


Attached are some pictures and diagrams that may be helpful.


My extreme thanks for any info/advice from those more experienced!

[cardminger]

Sorry it seemed to not correctly upload the files on the main post. Here are the attachments!

[Sailorman Ed]

I have an old Pathmaker that also just recently stopped working. Is there someone who repairs these?

[cardminger]

@Sailorman_Ed - I personally doubt that it is worth repairing. If I hear of anything I will let you know. My understanding is that usually the logic board fails which is basically not repairable.

[Sailorboy FIN]

@cardminger - ACR will technically do what you are looking for. If you place it to the same place where the PathMaker is now, it will isolate the batteries when the voltage of the batteries drops (Batteries are being used) and connects them back when the voltage goes up (like when you charge them). It’s very straight forward component, but keep in mind that it will only disconnect when the voltage drops bellow threshold. If I recall right, that open voltage is slightly bellow 13v and the connect voltage is 13v. If your Voltage is above 13v, the batteries will remain connected.

[smac999]

replace with two acr's.

acr is 2 banks, pathfinder is 3 banks. so you need two acrs

[GordMay]

Greetings and welcome aboard the CF, cardminger and Sailorboy FIN.

[Sailorboy FIN]

Originally Posted by smac999

replace with two acr's.

acr is 2 banks, pathfinder is 3 banks. so you need two acrs

I don’t see the need to separate banks 1 and 2. Both are house banks and, IMO, should work parallel at all time. The engine battery should be separated from banks 1 and 2. So one ACR should be sufficient.

[Locquatious]

Our original ACR's were damaged, possibly by hosing out the engine room. We substituted BEP 710-14A units because they seemed more water resistant but mainly because they provided a combine 13.2V/disconnect 12.7V that was close to where we wanted the operations.
Though we haven't checked lately, mosfet's are getting to the current capacity to withstand battery combining. Combiner units with such fets would not be subject to contact corrosion and would have much lower current demand when operating. Fets switch using microamps as opposed to the amp requirements for relays.

[cardminger]

@Sailorboy_FIN - I tend to agree that there is no reason the house banks need to be isolated from each other with the pathmaker / ACR, the main objective is to protect the engine battery from running down to the point where we cannot fire the engine. We do of course have a switch where we can switch which house bank is used (OFF | Bank 1 | Bank 2 | Both ) which I think would isolate the banks regardless of the ACR, assuming it is installed in the correct spot (maybe you can verify this with diagram above?)


I was considering the Blue Sea 7610 unit, $99 at West Marine. Do you think that would be sufficient for our uses?


Thanks again to all for the continued advice! Much appreciated!

[deblen]

Typical battery switching/charging diagram using a "auto combining relay"-ACR/VSR.
The output of the engine alternator, as well as the outputs of other bat. charge sources,may be connected to the + House bat.,rather than the + Start bat. if desired.


Cheers/ Len



https://www.dropbox.com/s/l7fuzp9c45...ching.pdf?dl=0

[Sailorboy FIN]

Originally Posted by cardminger

@Sailorboy_FIN - I tend to agree that there is no reason the house banks need to be isolated from each other with the pathmaker / ACR, the main objective is to protect the engine battery from running down to the point where we cannot fire the engine. We do of course have a switch where we can switch which house bank is used (OFF | Bank 1 | Bank 2 | Both ) which I think would isolate the banks regardless of the ACR, assuming it is installed in the correct spot (maybe you can verify this with diagram above?)


I was considering the Blue Sea 7610 unit, $99 at West Marine. Do you think that would be sufficient for our uses?


Thanks again to all for the continued advice! Much appreciated!

If the house battery switch has the options you stated above and it is wired correctly, it would be able to isolate the house banks.

The Blue Sea 7610 is exactly the part you need.

Always happy to help fellow sailor.

[smac999]

I just looked at your diagram. You said you had 2 house banks. But you only have one. If that diagram is correct.

The path maker is a 3 bank acr but only 2 are being used. So one acr is fine. But it should not be after the switches. That causes issues. Connect direct between house bank and engine battery.

If your house switch is a 1,2, all switch. Then you should have 2acrs. Direct to batteries. Not after switches as shown in your diagram.