Battery Charging Question

[seapadrik]

I recently replaced both my batteries on my Ericson 29 as they were very old and could not hold a charge.

I visited west marine and purchased these two:


SeaVolt group 24 12V Starting Battery
West Marine: SeaVolt Marine Starting Batteries Product Display


AGM group 24 12V deep cycle house battery
West Marine: SeaVolt AGM Batteries Product Display

The previous owner also has an inverter/charger setup that is connected directly to both batteries. This inverter is powered by a standard plug using shore power.

Will this combination work? After reading some of these posts it sounds like you can't use the same charger for an AGM and a standard wet battery?

I specifically asked the guy at west marine and he stated it is no problem using both kinds, just not to mix the GEL and AGM together.

Any advice is appreciated, I have been to the boat every day this week for maintenance so it is not yet a problem. But I want to figure out
a solution to keep these things charged.

thanks

[dorourke]

This sounds like a question for Sailingdog. We just discused something similar in another thread, he seems to know what he's talking about and mixing isn't a good thing. I don't know much about it eather but I'm learning.

[dorourke]

seapadrik, read the thread I posted on "dual battery set up". This might help, at lead you in the right direction.

[sailingdog]

Really not a good idea to mix AGM batteries and wet-cell batteries together. However, it is better than mixing either with Gel cells, which IMHO are more sensitive to improper charging and more easily damaged than either wet cells or AGMs.

You should have gotten two AGM batteries. That is often the best solution, especially if you have a fairly limited charging time frame. AGM batteries have the highest charge acceptance rate of any battery commonly used on boats. That means you can charge it to the 80% level faster than you could with wet-cells or gel batteries. The float charging, which you need to do after hitting the 80% bulk charge point, still takes about the same amount of time with either.

While some of the high-end chargers can handle different chemistry batteries, as they can be set to charge separate banks in different ways, however, it is generally not a good idea to mix chemistries, since the alternator and other less advanced charging sources will still cause some problems.

[seapadrik]

Thanks for the reply. Now I wish I would have gotten 2 AGM batteries. I guess my thought was that the starting battery is used only for starting the engine, no other connections, etc...And I would spring for the nicer AGM for the house battery.

I wonder if west would take back the wet cell battery and let me upgrade. This is getting expensive.

[sailingdog]

Yes, as long as you only recently bought the battery, I don't see why they wouldn't take it back. They're usually pretty good about returns, but it depends on the store... some are better than others.

[sailingdog]

BTW, a Group 24 sounds like an awfully small house battery bank, even for a boat the size of yours.

IIRC, it is only about 80 Amp Hours, you must not have a lot of electronics on-board your boat and must not take very long trips.

[seapadrik]

It is a bare minimum set-up as far as electronics go. I only recently purchased this boat and it isn't exactly wired to the gills. The group 24 size fit the existing bin. As I get more familiar with sailing in general and this boat I will no doubt consider more gadgets.