Golf cart batteries

[btrayfors]

Don,

You're living proof of what I said!

1. You have to know your batteries and your boat well.

2. If you're seeing 12.0VDC with a 6A load after drawing only 1/10 the capacity of your battery bank, then my guess is that either the batteries weren't fully charged to begin with or their capacity has been greatly reduced during the year you've had them....or both.

What is the voltage reading when you turn off the load?

How do you fully charge your batteries? Voltages used for bulk, absorption, and float? Have the batteries been equalized? Have you had them checked with a good capacity tester (like the Midtronics series testers), or have you done a controlled 20-hour capacity test?

One year old doesn't mean much. I've seen battery banks killed in less than a year. Also, new batteries can vary considerably in capacity. Nigel Calder once measured a difference of 30% in new batteries.

Finally, the battery monitor won't really tell you what's going on unless you know the answers to some/all of these questions, and unless the monitor has been accurately calibrated to your battery bank.

Bill

[AnchorageGuy]

We have been using Interstate EU2200 batteries for about ten years now. While extensively cruising and lots of discharge and recharge cycles we get about 7 to 8 years out of a pair. Typically if one battery in the pair goes bad we replace both. Cost of the Interstate is about $85.00 each. Chuck

[hellosailor]

Don, I expect something got lost in translation. If you take the "xx amp hour load" and strike the word "amp", then the numbers are veyr conventional.

Someone, probably the same fellow who invented the "GOLF CAR" battery, simply screwed up the terms.

[foggysail]

Originally Posted by Mambo

Request a trial membership. They'll generally give you 6 months free to try the place.

I tried this morning. NO BARGIN! I tried to get a business account, I have a rental apartment business in Rhode Island. That did not work either because there are no Sams in RI and before I could save $5 on a business membership fee vs a regular fee of $40, I needed to fill out a form, fax it to Massachusetts Department of Revenue or something for them to approve it because the business is out of state. I paid the extra $5 for a total membership cost of $40.

The trial membership has a gutcha! yes, you can use a trial membership ALTHOUGH YOU WILL SWALLOW A 10% PENALTY. I purchased 4 batteries which came to about $425 thereabout after taxes plus I oly had one dead one to return. So I ate another $45 until I return 2 huge dead ones in my van for a return of $30.

See, the 10% penalty would be greater than the membership fee.

All in all, I HAVE NO BITCHES!!! I saved over $200 this morning because of help in this thread.

Foggy

[foggysail]

Originally Posted by Seail

BatteriesPlus carrys the Trojan 105 and they have several store in MA. I picked them up on sale for 127.00 and they are normally 137.00

Really? I want to look them up because nobody else I checked with nor what I find on line offers their T105 for under about $160 and that place was in California. Northeast Battery in Providence, RI WANTED $207!!! They have at least two stores, one in Providence and another in Auburn, MA. Same phone 800 number for both stores.

Even if they offer sale specials, that was no good for me. I really needed then now. I will check Batteries Plus though.

Again--- I am happy with the purchase I made this morning

Foggy

[foggysail]

GREAT DISCUSSION THREAD--

CURRENT STATUS:

I purchased my 4 batteries! The two HUGE 150#+ that were in the bilge came out easier than I first thought with some help. One of the guys on my finger pier offered to help.....I quickly said THANK YOU! anyway, I tied a rope on one of the battery handles. Both of us were able to jerk the thing up one level, about two feet. Next tied another rope on the other end of the battery using its handle and together we just lifted it to the upper floor inside the boat. The rest was easy although heavy.

I would never, never use heavy batteries like those things! I can handle a 60-70# battery alone but not a 150#+ battery that is down in a bilge.

So as of tonight, my boat sleeps well. With new batteries, two new 140 watt solar panels on their way along with a questionable Chinese MPPT controller I should be in better shape.

Thanks to all who took the effort and offered suggestions/advice and even those who advocated using only Trojans which I know are a quality product. I am hoping to get more than 7 years out of today's purchase. Time will give proof of their quality or lack of it.

Foggy

[Maine Sail]

Originally Posted by cuthbert

Curious battery characteristics
Specifications

• 20 amp hour rate:230
• 5 amp hour rate:174
• 6 amp hour rate:178
• BCI Group Size:GC2

It is not a 20 amp hour rate it is a 20 hour rate or a 5 hour rate.

A 100Ah battery can support a 5A load for 20 hours before hitting 10.5V. The math is simple take the batteries rating and divide by 20 or 5 or 10 depending upon the hour rating..


100Ah battery at the 20 hour rate is:

100Ah/20 = 5A load
(the battery can support a 5A load for 20 hours before hitting 10.5 volts.)


100Ah battery at a 5 hour rate is:

100Ah/5 = 20A
(the battery can support a 20A load for 5 hours before hitting 10.5 volts.)

[Maine Sail]

Recently I've read a few posts, here and elsewhere where folks will say;

"At the rated 1A draw you'll get X amp hours." or "At the rated 5A draw you get X amp hours."

The Ah capacity used for deep cycle batteries, in marine applications and other industries, is very often a 20 hour Ah rating. There are also 5 hour and 10 hour ratings. Most battery monitors need this 20 hour rating to be programmed correctly and most all reputable battery manufacturers of deep cycle batteries can supply you with the 20 hour Ah rating. They will also supply you with the Peukert factor for correctly programming a battery monitor.

To figure the load your battery can support to deliver the same Ah's as the 20 hour rating you divide the rated 20 hour Ah capacity by 20. (Same as post above)

100Ah Battery / 20 = 5A

So a 100 Ah battery can support a 5A load for 20 hours before falling to 10.5V which is what the industry considers dead for the 20 hour capacity test.

Same math of different sized batteries:

60Ah Battery / 20 = 3A

So a 60Ah battery can only support a 3A load for 20 hours before hitting 10.5V.


130 Ah / 20 = 6.5A

And a 130 Ah battery can support a 6.5A load for 20 hours before hitting 10.5V.

As you can see the "rated load" is entirely dependent upon the Ah capacity of the specific battery in question and is not a simple 1A or 5A or 10A rating because it depends on the specific hour rating and Ah capacity of the battery.

Simply put a 60Ah battery can not have the same load applied to it as a 160Ah battery and still hit it's rated capacity over 20 hours.



But there is a gotcha, always is......


It is called the Peukert Effect. To dumb it down it means that any load applied to the battery above the 20 hour rating will result in less Ah capacity than the rating. On the other hand any load below the 20 hour rating will result in more Ah capacity.

I think looking at the math will help. This is the math on a 100Ah battery.

100 Ah Battery With A Peukert Factor of 1.25:

100Ah Battery - 80 Load = 50 Ah Capacity

100Ah Battery - 50A Load = 56.23 Ah Capacity

100Ah Battery - 40A Load =59.5 Ah Capacity

100Ah Battery - 30A Load = 63.9 Ah Capacity

100Ah Battery - 20A Load = 70.7 Ah Capacity

100Ah Battery - 10A Load = 84 Ah Capacity

100Ah Battery - 5A Load =100 Ah Capacity

100Ah Battery - 3A Load = 113.6 Ah Capacity

100Ah Battery With - 1A Load = 149.5 Ah Capacity


I highlighted the 5A load in red because that is exactly what the "divide Ah capacity by 20" gets you too..

Any load above the rated capacity of the 20 hour Ah rating results in less Ah capacity. Any load below the 20 hour capacity rating and you have more available Ah capacity..

It also helps to explain why a larger bank with smaller loads will survive better. It is not being cycled as deeply as you think if you are thinking in terms of the "face value" rating.

Take a parallel bank of four 100Ah batteries. With four you have a 20 hour rating that can support a 20A load, or 5A per battery, X 4 = 20A. When you run this bank at an average load of say 8A you'll really have a 503Ah bank not a 400Ah bank..

If you add just one more battery and make the bank 500 Ah you'll have a 25A support load, BUT, apply the same 8A load and you have a bank that can deliver 665 Ah's using the same average 8A load.

Conversely, size your bank small, at 100Ah, which would have a 5A support, and still apply the same 8A load and you really only have an 89 Ah bank. Bank size vs. load matters and the bigger the bank and the lower the load the less capacity you use and thus the shallower the discharge cycle. If you know your rough "average load" this can be calculated. Shallow discharges are good for the battery bank and deep discharges are bad so a bigger bank with the same load will be cycled less deeply, the way most people do it.

This is why we humans, unless perhaps you're Stephen Hawking, can't keep track of Ah capacity by simply watching the amp screen on a simple ammeter. I much prefer my Peukert calculated state of charge or % charged screen.

A battery monitor will make all these calculations for you internally and then represent them as a % of bank capacity or SOC. This of course only works well if it has been programmed correctly. The vast majority of battery monitors I see are not properly programmed. Better than 95% are still on the default Peukert #.. For proper programming, at a minimum, you need the banks total Ah capacity, at the 20 hour rate, and the Peukert factor for your specific batteries. A battery monitor can be a great tool but it is only as good as the person using it..

[Stu Jackson]

Originally Posted by Don Lucas

T

PS - I acturally have my monitor programed for a 400 AH bank instead of the 460 AH

Gee, why would you do that?

For everyone installing a battery monitor: The "Gotcha Algorithm" thread, a "MUST READ"

Link-series Charging Algorithms -- The "Gotcha" Factor!

DEFAULTS are factory settings that are made to be modified to suit your setup.

[Lagoon4us]

Originally Posted by foggysail

Really? I want to look them up because nobody else I checked with nor what I find on line offers their T105 for under about $160 and that place was in California. Northeast Battery in Providence, RI WANTED $207!!! They have at least two stores, one in Providence and another in Auburn, MA. Same phone 800 number for both stores.

Even if they offer sale specials, that was no good for me. I really needed then now. I will check Batteries Plus though.

Again--- I am happy with the purchase I made this morning

Foggy

In Australia $268:00 each.......

[FlyingCloud1937]

Originally Posted by foggysail

Really? I want to look them up because nobody else I checked with nor what I find on line offers their T105 for under about $160 and that place was in California. Northeast Battery in Providence, RI WANTED $207!!! They have at least two stores, one in Providence and another in Auburn, MA. Same phone 800 number for both stores.

Even if they offer sale specials, that was no good for me. I really needed then now. I will check Batteries Plus though.

Again--- I am happy with the purchase I made this morning

Foggy

As a Trojan dealer, my costs are 110.00 USD for T-105's , so mark-up may play a roll.

Gee.

Lloyd

[FlyingCloud1937]

Originally Posted by Don Lucas

The resting voltage thing just seems worthless overall. I need to believe the SOC while using my systems and before leaving the boat.

My 1 year old 460 AH batteries can start at 12.5 resting voltage and low 90% SOC of charge on my monitor and after 45 AH out at 5-6 amps and with the monitor now saying 80-85% SOC, the voltage with be reading 12V. And it reads the same on the panel volt meter and with a hand held.

So near as I can tell my voltage reading goes down a lot more than0.1 amps under 6 amps load.!

And yes the monitor has been syn'd recently and at the time the charge current had dropped to 2 amps.

PS - I acturally have my monitor programed for a 400 AH bank instead of the 460 AH

Don, you really should get out of the battery business, at the very least, you should not counsel anyone...including someone on the internet, or any one with an internet connection, on batteries

BC, really you don't understand the first thing about storage batteries.

I'm really thinking you should hire a professional bank manager for your own battery bank, as well as anything electrical.

Spend your time doing what ya know, instead of what ya don't know.

Lloyd

[brankin]

Originally Posted by onestepcsy37

the golf cart batteries sold at sams club are less than $80 each AND are made by east penn (it says so right on the battery). i bought four last year...

They are Duracell batteries and I have had them in my boat for the last 5 years and they are perfect.

[sailorboy1]

Originally Posted by FlyingCloud1937

Don, you really should get out of the battery business, at the very least, you should not counsel anyone...including someone on the internet, or any one with an internet connection, on batteries

I did not "counsel" anyone just listed what my batteries have done since day 1.

But I thank you for your useful information that provided no usefeul information. I'm sure you feel better about yourself for having done so.

[Maine Sail]

Originally Posted by brankin

They are Duracell batteries and I have had them in my boat for the last 5 years and they are perfect.

The license with Duracell & East Penn only began last year. You may have Energizers which were also sold by Sam's but they are made by JCI or Johnson Controls Inc..

It is a Duracell "labeled" battery but they are made by Deka/East Penn. They are not available in all states but are in about half of them..


Check out the manufacturer on the label, actually bottom left of the label on the top of the battery. They are not made by Duracell they are made by East Penn and labeled as "Duracell" under a licensing agreement.....

BTW this SAME EXACT BATTERY is sold by West Marine with a different sticker for $307.99 as the Sea Volt Deep Cycle AGM 105....