Anybody using AGM battery with Yamaha OB's

[hardee]

It looks like the singles (or big twins) are doing OK with the AGM's. Is there anybody using AGMs for over 2-3 years on a Yamahas system? Specially the little guys 40 or 50's?

Thanks again for timely response. Looks like I have until Tuesday to make up my other mind.

Harvey
SleepyC

[hardee]

I just got this back from the Technical Advisor at West Marine:

Quote:

"Hello Harvey, the Yamaha mechanic is correct in that Yamaha only supports the use of wet cell batteries. I personally checked with Yamaha. This is not because it will hurt the charging/alternator system, but what it does is that some how it shortens the life of the batteries. There is no way to fool the system that I know about, however from my experience, batteries never last more then 24/36 months anyway. They seem to have a switch that turns them dead. We do have a 18 month free replacement on the SeaVolt AGM batteries and a five year pro-rated warranty and you are correct West Marine stands behind anything that we sell. It is really up to you, however if Yamaha states that, I would go with their recommendation. Thanks," Paul Adler West Marine, Direct Sales 800 262 8464

If those AGM's are going to last only 2 years, I'm not much interested. Too expensive for only 2 years service. NAPA or Interstate will get my business.

Think I wnat to hear from the battery manufacture, but I guess it might nopt make any difference. The Query continues.......

Harvey
SleepyC

[hardee]

It looks like the AGM's are out of the running. Too bad that the Yamaha does not charge the AGM's with the finesse available with today's technologies. Seems like there must be a way, but I am running out of time so........

Next question. Has anybody tried getting a group 29 into the lazerette (starbd, and port) on a 22 Cruiser? My boat is in the shop in Port Townsend and I am trying to do this via remote control. Interstate makes a wet cell, Marine/RV "Deep Cycle Cranking" battery (#SRM-29) with the power requirements I am looking for, but I don't know if it will fit into the hole. The size is 13" x 6 3/4" x 10"high.

Thanks again,

Harvey
SleepyC

[Captains Cat]

Harvey, I had a 29 in each one on my 22 Cruiser but it was a '94 and I think the hatch was larger than the later boats...

Charlie

[Matt Gurnsey]

Somehow over the weekend I missed all this discussion, but Harvey and I have been going back and forth on the side.

I know that Gel cel and AGM like a different charge curve than the wet cels.

Looks like the AGM needs 14.7 volts to get the charge going, only .1 volts higher than wet cel. In fact, the recommendation is to use a wet cel setting if a specific AGM setting is not available on the charger.

In the West Marine advisor on Smart Battery Charging, it says that a 200 amp hour battery would be charged at 40-80 amps during the Bulk Charge Phase.

This may be the problem with the Yamaha 40's and the AGM battery, as the motors can't produce enough amperage . My concern would be that the AGM batteries may never get a full charge from the small outboards, drastically shortening their life.

If the bulk of use of the boat is dock to dock, then using the 110V system charger would probably keep the batteries in good condition.

But-

I think many C-Dory owners enjoy being on the hook and without 110V hookups, and I know that Sleepy-C has two C-PAP machines going overnight, which will put a drain on the battery running the engines for a few hours will not produce enough amps to restore the charge.

With AGM batteries at twice the cost of a dual purpose wet cel, it would be an expensive lesson to learn if the AGM's fail after two years (especially when Harvey is getting longer life out of his wet cels).

Even adding extra batteries for extra capacity is problematic with the twin 40's, as the alternator output can't produce enough amperage to fully recharge the batteries.

Now, if we all wanted to chip into Harvey's battery purchase to support an experiment in AGM battery use with small outboards, I'm sure he would be happy to provide progress reports.

[hardee]

Matt said:

[Matt Gurnsey]

I think you're right about the big outboards, but I don't think it's voltage, but amperage.

[SEA3PO]

Actually the problem is not to the battery but the voltage regulator going out..... mine failed the first time after I installed new batterys....

I do agree that most of the time I keep the batterys charged from the built in charger and rarely am away from 110v long enough to need a full heavy charge for a sustained time to bring up a low battery.. the time my voltage regulator failed was one of those rare times that the battery got low and required a full heavy charge... regulator was just not up to it.... I really think the motors need a genuine alternator..not a charging loop.

Joel
SEA3PO

[marvin4239]

[thataway]

"Undercharging" will occur if there is insufficient current output no matter if you use AGM or flooded lead acid batteries. If the boat is not able to maintain the needed charge with only the engines, there is the option of using a 1000 watt Honda generator, or solar cells to give the additional power.

In reality, many cruisers will anchor for a couple of days, and then tie up to a marina for a day--for showers, water, etc. This gives a chance to top off the batteries.

Even with big alternators, unless the engine is running long hours, batteries will often only come to 80 to 90% charge capacity. They are topped off when the genset or shore power is used.

In this specific instance, if the boat is not kept in a slip or at home--left in a stroage lot, then a solar panel will be best. The battery will not be damaged by a few days of sub optimal charge. In fact this is an argument for more batteries. You want to keep the battery from draining to less than 12.2 volts or 50% of its capacity. As I understand it, the AGM batteries are so that they can be put in the cabin. This is one of the good justifications for AGM batteries.

[hardee]

Dr Bob said:

[thataway]

I personally would go with the AGM batteries: try and keep them charged up as much as possible at home or at the dock. I suspect that you are not out more than one or two nights at a time the majority of the trips. Is the 5 amps at 12 volts? Is it for each machine? What do you figure the amount of power you will use each night total for the c PAP machines?

I think that the answer " however from my experience, batteries never last more then 24/36 months anyway. They seem to have a switch that turns them dead. " from West marine is a bit far out. West Marine often gets batteries back at the end of the warantee because of their liberal exchange policy, Most boaters abuse batteries. I find that my batteries last at least 4 to 5 years--and that is with heavy use.

Now having said all about the AGM and wet cell inside the cabin--I have been sailing with wet cells inside the cabins of my boat from 1961 until about 2000, when I went over to AGM's We had over 1000 amp hours of wet cells in our motor sailers which were open to the pilot house and heavily used them each day with charging rates of up to 300 amps an hour. They were ventillated well, but never caused a problem.

[marvin4239]

The following is from the brochure on the Sears AGM batteries

"At room temperature charge at 30 to 40 amps with maximum voltage of 14.7 for 8 hours float charge at 13.6 volts."

This would lead you to believe that the stock 20 Amp Guest chargers C-Dory installs maynot be adequate and an upgrade to a larger charger might be in order. I think some have done this already. My stock charger has three outputs one 10 amp and two 5 amps. The two 5 amps can be tied together for 10 amps total. I have mine configured so the 10 Amp circuit goes to the start battery and the two 5 amp circuits are tied together and going to the two group 24 agm's which are parralled. Incidently Sear calls thier group 24 size "34M" and they are not as tall as the standard group 24 lead acid battery. I haven't been able to get out and test the system but when I'm able I'll report how it works. The plus for me with the AGM's is it's virtually impossible to get to the batteries to service them when two are put in the lazarrette. The Sears AGM group 24s are $189 and the group 31 is $239 which is a pretty significant difference over lead acid but the three year full replacement warranty may make it worthwhile. They claim they can be safely discharged at a much lower value (10.5 volts) than lead acid batteries but hopefully I won't be testing this feature.

[hardee]

Looks like we can fit Interstate G-29s, so one can go on each side. Marine /RV Deep Cycle type (Interstate number SRM-29 with lots of power. 675 CCA, 845 MCA, and 210 Reserve Capacity. That all equals 21 hours at 5 amps or 6.4 at 15 amps, which will be about 9 hours of CPAP time for both machines. Only a hair larger than a group 27 with considerable more punch, both at the battery and in the wallet Over all making for a better nights sleep, and getting to anchor out now = priceless. =two very happy CPAPers.

I must say, it is not the AGM, and I will be looking at them again in a year or 5 (or 6) and we will see what has transpired by then. I still think they are the ideal battery for the C-Dory Cruiser. (Come on Yamaha, get in line)

Harvey
SleepyC

[Dreamer]