Onwards to the Battery Monitor

[Roger Long]

[FONT=&quot]Thanks for coming by this morning and checking the batteries. 76% and 57% life for 5 year old AGM’s with this service history doesn’t strike me as too bad, even if the tester tends to be optimistic with that battery type. I know it’s only a rough check but it is encouraging since the batteries weren’t fully charged. I wish I’d known that the 3 stage charger going into float mode doesn’t indicate full charge. I would have run it a lot longer these past years when I had the opportunity.

I’m sold on the battery monitor and it will go in as soon as it arrives. I’ll use that to run a full 20 hour test and reassess. If the batteries aren’t much worse than we found today, I’ll probably stick with AGM due to my acid phobia. I’m sure I’ll replace them in any event because it’s easier to do now than somewhere up in Canada.

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[Stu Jackson]

Once you get your battery monitor, don't forget to read the "Gotcha" algorithm topic. May not apply to you without refrigeration (am I correct on that?) but handy to know about in any event.

http://c34.org/bbs/index.php/topic,4922.0.html

 

[Roger Long]

don't forget to read the "Gotcha" algorithm topic.

I got the Victron. Do you think this is inherent in all monitors or specific to the Link?

 

[Stu Jackson]

Roger, it's for all of them, as noted in the (long) text of the link I provided. The reason is very simple: all algorithms have "default" values. Depending on your monitor, and your electrical system and battery capacity, you 'll have to "do the math" to figure out if the defaults work for you or if they have to be tweaked.

 

[Roger Long]

it's for all of them, as noted in the (long) text of the link I provided.

Thanks for saving me the long read. My head was spinning last night before I got through the first paragraph. Too late in the day.

I'd already gotten from the Victron manual that programming is essential. The factory defaults for that unit assume a 200 Ah bank so I can't use them anyway since mine is 158. There are several factors I'll have to find out from the maker of the batteries. Knowing independently from the monitor that the batteries are fully charged and pressing the button sequence for automatic sync seems an essential installation step.

 

[Roger Long]

Here is the compact arrangement of the negative buss bar and the Victron shunt using a copper bar instead of a cable.

 

[Stu Jackson]

Lookin' good. Once you get it installed, please go back and read the link I posted that got your head spinning (you're not the only one!). Once you start playing around with it, the thread will become much more understandable.

 

[Roger Long]

AGM Data Point

I just picked up my batteries from Broad-Ray Batteries. Their charger kept tripping into float mode before the 2005 AGM's reached full charge condition so they didn't think it was worth running a 20 hour test on them. Ray said they have some life left in them but shouldn't be used on something critical like a boat.

These batteries got used with pretty shallow discharge cycles and experienced frequent 6+ hour runs under power and nearly daily engine operatoin so life for them was about as good as it gets with a cast iron voltage regulator and no solar. The first three seasons, they got frequent shore power charging.

If I put new AGM's in, I'll plan on 5 year replacement.

 

[Stu Jackson]

Roger, you said "if" - are you considering other battery types? Given Maine Sail's excellent discussion of the issues surrounding AGMs, are you considering wet cells?

 

[Roger Long]

Given Maine Sail's excellent discussion of the issues surrounding AGMs, are you considering wet cells?

The credit card bill that just arrived in the mail and the other things I keep discovering on the boat have more to do with it than his discussion. We talked about it face to face and he thinks AGM's are a reasonable decision for my situation, especially now that I will be able to keep a better eye on them and know to watch the alternator temps if I get into a low battery situation.

I was thinking about wet cells a little more seriously before worming upside down into my battery "tunnel" to pull the batteries and dropping one on it's side next to my face. If that had been a wet cell and a cover popped off, it would have been a mess. That experience makes an extra $200 every 5 years not seem very extravagant.

 

[Stu Jackson]

Good call. I have a dockmate with a Mason 33, I think I mentioned sometime ago, who had his batteries in way aft in an impossible to get to place. I fully understand. I guess it's AGMs or gels. Good luck with your list.

Stu