Battery chargers

[Maynard Rupp]

I know this subject has been tossed around before, but I still don't get it. We have the original 1986 battery charger on our 36'C. It seems that we get about 2 years out of those heavy 8D batteries. Our boat is plugged in at the dock and I keep the battery charger on. I am concerned that the bilge pumps could quit if the boat leaked badly and the charger was off. The paper work for the charger seems to indicate that the charge rate lessens as the battery becomes fully charged. Am I ruining my batteries by leaving that charger on? Would a more modern charger help this situation? Can anyone recommend a good, (better than we have), charger? These batteries work fine until they suddenly stop puting out voltage at all. BAH!!

 

[OBXTucker]

There's a great thread ongoing right now about Outback's and Analytic's.
I'm assuming you're using the old Sentry's and I can speak from authority in saying that they WILL cook your batteries if left on 24/7. How much distilled water are you going through (you are using distilled, correct)?

Join the other thread, a lot of information there.

 

[SKYCHENEY]

Some seem to have good luck putting a timer on those old chargers so they only run a few hours/day.

 

[spcoolin]

I've said it before...Even written long posts about it...But a properly operating SENTRY charger WILL NOT BOIL Batteries...
(Hatteras also installed LaMarche chargers that would boil batteries)

If a Sentry does boil batteries...
Either someone has put it into the manual mode (switch) where it won't shut off...
Or...It's control board is out of calibration or bad... It can be replaced for less than $200...

No...A Sentry is not new technology that will charge batteries as fast as the newer technologies will, but it's a set it & forget it charger, it's practically bullet proof, and every part inside is still available for replacement if needed...

Be aware that most of the newer smart chargers are a circuit board inside a box...Generally that board can't handle much abuse, and once it fails you have no manual bypass mode/switch...The board is also very expensive...

I'm not putting down the newer chargers but what I'm suggesting is:
You may want to think about leaving a Sentry intact & installing the newer charger if you want...Just keep the reliable, repairable Sentry installed as a standby.

Steve~

 

[fissioneng]

I've said it before...Even written long posts about it...But a properly operating SENTRY charger WILL NOT BOIL Batteries...

If a Sentry does boil batteries...
Either someone has put it into the manual mode (switch) where it won't shut off...
Or...It's control board is out of calibration or bad... It can be replaced for less than $200...

Or you have bad cell in the "control" battery, then the "non-control" battery gets the heck charged out of it when it doesn't need it. The Sentry can't detect a bad cell.

Or if the "control" battery needs charge, the "non-control" battery gets too much charge.

The problem with some Sentry's (my old one) is that they can't discriminate between the batteries. Whatever the "control" needs, the other one gets too.

I have never heard of a smart charger failure, but I'm sure it has happened. I have owned one for 10 years.

 

[REBrueckner]

You are using lead acid, not AGM nor gel batteries, right?

If they are using a lot of water, then they are being overcharged....It could be becaause an appliance is running and the Sentry may provide too much charge...more current than is needed to run the appliance....I do not know how good a job they do in that situation, which is abnormal.

Any significant overcharge would cause loss of water. That's a goof first test. When I ran my Hatt cruising full time for six months, and used 12 power full time, I found my 7 x 8D wet cell/lead acid batteries would take over a gallon of water...say 5 quarts at the end of the season. Not a lot for that much liquid capacity. Sitting mostly idle during about five mos of winter with light use, they would still use maybe 2-3 qts and I always topped them off before departing.

Over 11 years of use, several different brands would fail at about four years....maybe three years on on occassion. and it was usually because of a weak cell of two...most cells seemed fine, but one weak cell per pair or one per battery significantly altered power and I learned others would fail sooner rather than later....several times a majority of the cells cells got weak. When I replaced my Sentry with Statpower smart charges, the batteries charged faster, and I had three 40 amp chargers for genny use, but the batteries did not seem to last longer. So I ended up often buying two new 8D's every year among my three battery banks, that way I always had one bank of new batteries aboard.

Last fall, I checked three car batteries...my wife's and mine and my daughter...each tested just fine with a hyrdometer...about 3/4 or so charge as I recall. This spring, just six mos later, BOTH my and my wife's batteries failed!!!! (One was Duralast, from Pep Boys, another Exide.) (about three or four years old) So about six months after testing ok, each battery now had several virtually "dead" cells.

If the batteries are NOT being used when you are away, the normal situation, try feeling them for warmth...by hand or an infrared thermometer...idle batteries should NOT be warm to the touch.

You can also check the voltage at the battery terminals when systems are idle,,a voltage of 14, for example, is way too high if you detect that repeatedly....I've forgotten what normal idle voltage for a Sentry would be no more than 13 and 12.6 is likely better ....

 

[REBrueckner]

You are using lead acid, not AGM or gel batteries, right?

If they are using a lot of water, then they are being overcharged....It could be becaause an appliance is running and the Sentry may provide too much charge...more current than is needed to run the appliance....I do not know how good a job they do in that situation, which is abnormal.

Any significant overcharge would cause loss of water. That's a good first test. When I ran my Hatt cruising full time for six months, and used 12 power full time, I found my 7 x 8D wet cell/lead acid batteries would take over a gallon of water...say 5 quarts at the end of the season. Not a lot for that much liquid capacity. Sitting mostly idle during about five mos of winter with light use, they would still use maybe 2-3 qts and I always topped them off before departing.

Over 11 years of use, several different brands would fail at about four years....maybe three years on on occassion. and it was usually because of a weak cell of two...most cells seemed fine, but one weak cell per pair or one per battery significantly altered power and I learned others would fail sooner rather than later....several times a majority of the cells cells got weak. When I replaced my Sentry with Statpower smart charges, the batteries charged faster, and I had three 40 amp chargers for genny use, but the batteries did not seem to last longer. So I ended up often buying two new 8D's every year among my three battery banks, that way I always had one bank of new batteries aboard.

Last fall, I checked three car batteries...my wife's and mine and my daughter...each tested just fine with a hyrdometer...about 3/4 or so charge as I recall. This spring, just six mos later, BOTH my and my wife's batteries failed!!!! (One was Duralast, from Pep Boys, another Exide.) (about three or four years old) So about six months after testing ok, each battery now had several virtually "dead" cells.

If the batteries are NOT being used when you are away, the normal situation, try feeling them for warmth...by hand or an infrared thermometer...idle batteries should NOT be warm to the touch.

You can also check the voltage at the battery terminals when systems are idle,,a voltage of 14, for example, is way too high if you detect that repeatedly....I've forgotten what normal idle voltage for a Sentry would be no more than 13 I suspect....

 

[REBrueckner]

You are using lead acid, not AGM or gel batteries, right?

If they are using a lot of water, then they are being overcharged....It could be becaause an appliance is running and the Sentry may provide too much charge...more current than is needed to run the appliance....I do not know how good a job they do in that situation, which is abnormal.

Any significant overcharge would cause loss of water. That's a goof first test. When I ran my Hatt cruising full time for six months, and used 12 power full time, I found my 7 x 8D wet cell/lead acid batteries would take over a gallon of water...say 5 quarts at the end of the season. Not a lot for that much liquid capacity. Sitting mostly idle during about five mos of winter with light use, they would still use maybe 2-3 qts and I always topped them off before departing.

Over 11 years of use, several different brands would fail at about four years....maybe three years on on occassion. and it was usually because of a weak cell of two...most cells seemed fine, but one weak cell per pair or one per battery significantly altered power and I learned others would fail sooner rather than later....several times a majority of the cells cells got weak. When I replaced my Sentry with Statpower smart charges, the batteries charged faster, and I had three 40 amp chargers for genny use, but the batteries did not seem to last longer. So I ended up often buying two new 8D's every year among my three battery banks, that way I always had one bank of new batteries aboard.

Last fall, I checked three car batteries...my wife's and mine and my daughter...each tested just fine with a hyrdometer...about 3/4 or so charge as I recall. This spring, just six mos later, BOTH my and my wife's batteries failed!!!! (One was Duralast, from Pep Boys, another Exide.) (about three or four years old) So about six months after testing ok, each battery now had several virtually "dead" cells.

If the batteries are NOT being used when you are away, the normal situation, try feeling them for warmth...by hand or an infrared thermometer...idle batteries should NOT be warm to the touch.

You can also check the voltage at the battery terminals when systems are idle,,a voltage of 14, for example, is way too high if you detect that repeatedly....I've forgotten what normal idle voltage for a Sentry would be no more than 13 I suspect....

 

[bobk]

I had this issue with the OEM Newmar charger on my trawler. Newmar sold me a 'CCB', Charge control box, for about $100 about 20 years ago and it solved the problem.

 

[rsmith]

I know this subject has been tossed around before, but I still don't get it. We have the original 1986 battery charger on our 36'C. It seems that we get about 2 years out of those heavy 8D batteries. Our boat is plugged in at the dock and I keep the battery charger on. I am concerned that the bilge pumps could quit if the boat leaked badly and the charger was off. The paper work for the charger seems to indicate that the charge rate lessens as the battery becomes fully charged. Am I ruining my batteries by leaving that charger on? Would a more modern charger help this situation? Can anyone recommend a good, (better than we have), charger? These batteries work fine until they suddenly stop puting out voltage at all. BAH!!

I had a sentry on the boat for 30 years worked great I did have a timer on it for when I left the boat. since then I ve been thru 2 ferro chargers and both have been cooking the batts out.
As far as the pump I was always worried about the 32v pump so I mounted a 110v submersible pump from grainger above the dc pump. I got a fiberglass pump with a built in float switch. its got its own thru hull and is far greater capacity than the dc pumps. since its above the normal bilge level it wont come on unless its a emergency. like all backup stuff I test it once in a while to make sure its still works

 

[jim rosenthal]

My Hatteras came with a Sentry charger. It did cook the batteries, in spite of being returned to a Sentry authorized dealer and rebuilt with a new board inside it. They were well-made old units, but I got tired of replacing 8D batteries.

I replaced it with a Statpower 40 which has worked faultlessly for years now. That company is now Xantrex; their customer service isn't very good, but I can't complain about the chargers.

Most companies make high-frequency "smart" chargers which are now the industry standard. So does Sentry, if you want one of their products. Charles Marine chargers are also supposed to be very good; I haven't had one myself. I would take your old charger out, and put it on the shelf in the powerboat antique museum along with the Loran-A (and now Loran-C, sadly), your ADF, your AM ship-to-shore radio, your brass knot log, your bosun's pipe, etc etc. It is obsolete.

I would buy another charger similar to the one I have now- as a matter of fact a friend has an unused one which I am trying to buy from him as a spare. Don't forget to run a separate set of returns for the charger- it seems to be essential to have a return path for the charge current and not depend on the rest of the electrical system to provide an adequate return path to the charger. I had problems reaching full charge until I did this- I used black Ancor cable of the same dimension as the charging cables, and it has all worked perfectly ever since.

 

[Boatnut]

My Hatteras came with a Sentry charger. It did cook the batteries, in spite of being returned to a Sentry authorized dealer and rebuilt with a new board inside it. They were well-made old units, but I got tired of replacing 8D batteries.

I replaced it with a Statpower 40 which has worked faultlessly for years now. That company is now Xantrex; their customer service isn't very good, but I can't complain about the chargers.

Most companies make high-frequency "smart" chargers which are now the industry standard. So does Sentry, if you want one of their products. Charles Marine chargers are also supposed to be very good; I haven't had one myself. I would take your old charger out, and put it on the shelf in the powerboat antique museum along with the Loran-A (and now Loran-C, sadly), your ADF, your AM ship-to-shore radio, your brass knot log, your bosun's pipe, etc etc. It is obsolete.


I would buy another charger similar to the one I have now- as a matter of fact a friend has an unused one which I am trying to buy from him as a spare. Don't forget to run a separate set of returns for the charger- it seems to be essential to have a return path for the charge current and not depend on the rest of the electrical system to provide an adequate return path to the charger. I had problems reaching full charge until I did this- I used black Ancor cable of the same dimension as the charging cables, and it has all worked perfectly ever since.

Can you give us a manufacturers name of the high frequency "smart" chargers that are the industry standard now?

Thanks

 

[REBrueckner]

manufacturers: Xantrex now owns Statpower and Tripp and a few other brands, I think Charles is still independent and has a cool looking stainless steel case. These recommended names and a few others have been posted in other threads....

If you have time, check E-bay for Statpower often at a good discount and be sure to get the remote display/status panel. After a few months of checking your ststus panel while recharging, you'll be able to tell from how fast the battery recharges, when it's getting weak....as the batteries age charging takes longer, even when equalized regularly.

I used three in parallel simultaneously for a fast charge when crusing away from shorepower and they worked very well together.

 

[bostonhatteras]

here's a testimonial for good 8d batts and smart chargers. in april 2002 I installed 4 rolls 8ds and one xantrex 40 amp smart charger. the batteries have used about 1 gallon of water, each, per year. the previous batteries where Trojan and only lasted 3 years being charged by the original sentry charger. the rolls batteries also have been charged for 2 years now by a xantrex ms 2000 watt inverter/ 100 amp charger (40 amp is simply shut off) and have the same water usage. btw I didnt put the sentry in a museum, I put it in the trash along with a brand new in the box 15 amp newmar ferro ressonant charger. no one and I mean no one wanted the newmar even for free. the least expensive smart charger is 10 times better than that newmar.
IMHO
Russ

 

[Maynard Rupp]

Thanks to all for your very good thoughts. Our charger is a Pro Mariner and is the original 1986 unit installed by Hatteras. Of course it is a fero unit. Maybe it is time for a new Xantrax charger. Our 8D batteries never last more than 2 years. Our current batteries are a Deca and an Interstate. I have heard that all wet 8D batteries are made by the same company. That wouldn't surprise me much. Our charger is on 24/7 anytime the boat is at the dock. We don't use any power from the house battery though. We want that charger on to cover a bilge pump power need in case our great Hat springs a leak.")

 

[dave1985]

Hi Maynard,

I have the same charger in my 1985 36. I was amazed the other day when I went to top off the batteries and they only took about a pint and a half total combined. This is since last November with them on 24 hours a day though, granted there was not a lot of draw on them over the winter. One battery is nine years old and the other three. As Steve noted, it's a pretty solid set up. It might be worth trying to see if some tech support's available to see if your's is out of specs before going to the trouble of swapping it out and that not being the solution.