Batteries ? ? ?

[Bloodhound]

My reading is that a rested 12.8V battery at ambient temperaure is fully charged. Perhaps you should do a load test before spending on new batteries.

[jaydh]

Hi,

For what it's worth last group of 4 Trojan T-105 batteries lasted five years. Only charging was from 4 55w panels and a Rutland 913 windgen. Full time cruising over that time period, no marinas or plug in power/charging. They were sold with the boat, but condition of them afterwards is unknown. We're buying Trojan again.

Best - J

[BigCat]

Originally Posted by jaydh

Hi,

For what it's worth last group of 4 Trojan T-105 batteries lasted five years. Only charging was from 4 55w panels and a Rutland 913 windgen. Full time cruising over that time period, no marinas or plug in power/charging. They were sold with the boat, but condition of them afterwards is unknown. We're buying Trojan again.

Best - J

They have a great reputation. It's my belief that more batteries are wrecked by shore based charges than anything else.

[sandy daugherty]

Its best to know what your needs are before you go battery shopping. Does anyone recall a spreadsheet that calculated house loads from a fairsized list of gadgets?

[schoonerdog]

Ask and you shall recieve

Battery Cost Model Inputs and Outputs: Gel, AGM, Flooded

and here

http://www.batterytown.co.nz/Downloa..._worksheet.xls

[BigCat]

Originally Posted by Rick

No lead-acid battery (AGM included) exhibits a so-called "memory effect". It has been shown that even in the case of Ni-Cad batteries if a proper acceptance voltage is used for recharging no problems with capacity recovery will be experienced (barring other effects of aging, or damaging phenomenon).

Not according to the manufacturer of Lifeline batteries. Take it up with them-

[sandy daugherty]

Thanks Schoonerdog. And Thanks for the intro to Zach!

[schoonerdog]

Sandy, where are you? You should drop by ALM and say "hi" sometime, we're historic part of the PDQ 36 fan club!

[sandy daugherty]

Schoonerdog!

Page 83 is in Glebe Bay on the South River, full of holes inside, waiting for me to drag a gazillion wires and gadgets to her from the dining room and living room. And part of the TV room, and the basement, and both cars. She has new sails, new engines, new batteries, new toys, and the aforementioned menagerie of electronics, some of which was not meant for prime time consumption, like the IR camera that is going to see crab trap floats at 300 feet at night. [right] I've learned from you and another PDQ alum that a smaller old boat is [just barely] less trouble than a bigger old boat. Did you know Sea Paws ?

The photography at zachaboard is WONDERFUL!

[mark_morwood]

Originally Posted by BigCat

Not according to the manufacturer of Lifeline batteries. Take it up with them-

Do you have a reference on that? I searched their web-site and couldn't find anything. Everything else I've seen says there is no memory effect on lead-acid batteries of any type, but I've never seen on statement either way from an actual manufacturer.

Thanks,
Mark

[xxuxx]

Originally Posted by jaydh

Hi,

For what it's worth last group of 4 Trojan T-105 batteries lasted five years. Only charging was from 4 55w panels and a Rutland 913 windgen. Full time cruising over that time period, no marinas or plug in power/charging. They were sold with the boat, but condition of them afterwards is unknown. We're buying Trojan again.

Best - J

I second that info, or I third it1 Five years is a long time with the same batteries and cudos on the rutland.....extremely quiet and reliable.

[BobJ]

Originally Posted by sandy daugherty

Its best to know what your needs are before you go battery shopping. Does anyone recall a spreadsheet that calculated house loads from a fairsized list of gadgets?

Electrical Budgets

Sandy, here are the electrical budgets from this year's Solo TransPac fleet. The boats ranged in size from 20 to 60 feet. The blank Excel worksheet is also available on the website.

Although many of the boats are very cruisy racers, their installed gadgets may not be not as numerous as what many cruisers have. Also, some did a better job than others at completing the worksheet - it was the first year for the requirement and there was much grumbling!

I know Ragtime! tested the draw from each gadget. Alchera's is pretty complete and accurate too.

[btrayfors]

BobJ and Sandy,

Thanks for the reference. This is a very useful thing for all cruising boats to do.

I took a quick look at five of them (Alchera, Chesapeake, Dream Chaser, Nana, and Ragtime).

Some very useful data there. However, I did note a couple of things which seem off:

1. refrigeration consumption was very low, compared to installations I know about; not many boats are going to get by with 20-30AH total draw per 24 hours;

2. computer consumption was way low, at least for laptops. They certainly draw more than the 16-25 watts shown....many draw 6-7 amps; maybe they're talking about dedicated chartplotters?

3. SSB transmit draw was often shown as near the maximum; while this could happen with data transmission, SSB voice is way less...more like 40-60% of maximum draw average.

4. some didn't seem complete, i.e., they must have had some of the equipment onboard for which no data were shown. Of course, as you said, these are racing boats, or at least boats participating in a race.

5. the recommended battery size apparently results from a simple multiplication factor, and doesn't take account of the boat's size, things missed in the listing, etc. Some of these seem way off, e.g., the recommended battery size of about 100AH (for the boat which showed an incredibly low 73AH/day consumption rate). I wouldn't set off for Hawaii in ANY boat with only 100AH of house battery power aboard :-)

6. the charge times are, as the spreadsheet says, based on 100% alternator output. This only happens for the first few minutes. After the alternator warms up, it's output will be reduced. Might have been better to build in a compensating factor, like 75% of alternator output.

Some of these boats were no doubt fitted with energy monitors, like the Link series. I'd be interested to know how closely the results on paper came to the "actuals" as measured by the monitors.

All-in-all, a very useful exercise, though.

Bill

[BobJ]

Originally Posted by btrayfors

All-in-all, a very useful exercise, though.

Bill, that was the main point. Over the 30 years of this race, by far the most problems aboard the boats have been with their electrical systems. Typically a boat would run out of electrons part way through the race and unless they had a wind vane, they would face hand-steering the rest of the way to Hawaii. Another common problem is they would start missing check-ins because there wasn't enough juice left in their batteries to transmit on their SSB. This new requirement, if continued by future race committees, will at least make the entrants think through the issues.

I agree with most of your observations about the data. On my boat (Ragtime!), the individual factors varied from my projections but the end result (charging time per day) came out about right. Generally I used fewer electrons than expected and you're right, the alternator output was lower (more like 15-20 amps). I have a Link 20 monitor.

Most boats were very optimistic about the contribution from their solar panels. There was a lot of overcast during the last two races for sure.

Anyway, as you say, a good exercise that all of us should go through.

[AnchorageGuy]

12.8 volts sitting on your battery charger or at rest? Makes a big difference. If it is 12.8 at rest, and this is with no load whatsoever for a period of 4 to 5 hours, then there is nothing wrong with your batteries. You should do a load test on them "at rest" just to be sure. If this is 12.8 volts sitting on your charger then something is wrong with your charger. How are you measuring the voltage and are you SURE that is the correct measurements?