Power Outage

Bill Schoenherr of Midland, Michigan, asks:"My gelcell batteries are 8 years old and although they are showing no signs of age, I have abused them by discharging them below 50 percent of their capacity. I’m considering replacing them because we cruise the Great Lakes in the North Channel area and I would hate to have them fail up there. Are TPPL batteries (Odyssey) still
Author:
Publish date:

Bill Schoenherr of Midland, Michigan, asks:

"My gelcell batteries are 8 years old and although they are showing no signs of age, I have abused them by discharging them below 50 percent of their capacity. I’m considering replacing them because we cruise the Great Lakes in the North Channel area and I would hate to have them fail up there. Are TPPL batteries (Odyssey) still the way to go? I can’t find any additional information on alternatives like the Oasis battery technology."

Nigel Calder replies:

You’ve done well with your gelcells, but before discarding them you might want to perform a capacity test. Bring them to a full charge and then discharge them at 1/20th of their rated capacity (i.e., 5 amps for every 100 amp-hours of battery capacity). You’ll need an ammeter to measure the discharge rate. If you don’t have one on board, there’s an excellent clamp-on DC ammeter that reads to 400 amps in the Sears on–line catalog for $60: part # 03482369000 (sears.com).

Use the boat’s interior lighting to impose the necessary load. You’ll need to monitor voltage and stop the test when it falls to 10.5 volts. If this occurs in less than 16 hours, the battery has less than 80 percent remaining capacity and should be replaced. If it holds up for 16 or more hours, you can hang onto it a bit longer. Be sure to recharge it immediately to avoid damage.

You’ll get maximum benefit from Odyssey TPPLs and other such batteries only if you have charging devices that are powerful enough to take advantage of their high charge-acceptance capacity, and if you spend time running the engine just to charge batteries. In this case I would seriously consider them. But you may run the risk of burning up your alternator, because the batteries will drive it to full continuous output for extended periods of time.

Related

qr_main

Antal: QR Clutch

Get a Grip Italian deck gear maker Antal’s two new QR clutches not only have high holding power—up to 3,500lb for the QR10 and 4,800lb for the QR12—they can be opened and released under maximum load, so there’s no longer any need to take up the strain on a winch before freeing a ...read more

leadpicBoxes

DIY: Easy Drawers and Boxes

During the extensive refit of my Pearson 40, I needed to create a significant number of custom-sized plywood drawers and stowage bins, or boxes. These included 10 under-floor storage bins, under-sink organizers, boxes for tools and stores, and even a specially fitted cat ...read more

ARC2018Flags

Tips on Gaining Experience Passagemaking

Whether you want to build a sailing resume or just gain practical experience, getting more miles under your keel is key. You can sail a lifetime of summer afternoons and never quite get the hang of cruising—where creativity and offshore savvy result in self-sufficiency and ...read more

arc18-3981

Stories from the Cruisers of the ARC

Each December, the docks at Rodney Bay Marina in St. Lucia are abuzz as the fleet of the ARC—the Atlantic Rally for Cruisers—arrives to much fanfare. No matter what time of day or night, the staff of the World Cruising Club, organizers of the 33-year-old rally, are there to ...read more

TOTW_PromoSite

SAIL's Tip of the Week

Presented by Vetus-Maxwell. Got a tip? Send it to sailmail@sailmagazine.com A sign from outside the box  Rev counters on modern engines are driven electronically from a terminal on the alternator. If all is well, as soon as the engine fires up the revs will read true. If, ...read more

emSelf-tacking-jib

Ask Sail: Are Self-trackers Worth It?

Q: I’m seeing more and more self-tacking jibs out on the water (and in the pages of SAIL) these days. I can’t help thinking these boats are all hopelessly underpowered, especially off the wind, when compared to boats with even slightly overlapping headsails. But I could be ...read more

01-LEAD-hose-leak-CREDIT-BoatUS

Know how: Is Your Bilge Pump up to the Job?

Without much reflection, I recently replaced my broken bilge pump with a slightly larger model. After all, I thought, surely an 800 gallon-per-hour (gph) pump will outperform the previous 500gph unit? Well, yes, but that’s no reason to feel much safer, as I soon discovered. The ...read more