Author Topic: Deep cycle battery life expectancy. Did I buy a bunk battery?  (Read 2995 times)

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zracer

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I bought a group 27 deep cycle starting battery from O'Reilly auto parts in March and the battery was manufactured in that same month 3/16.

The battery didn't last and I'm looking to find out if I'm doing something wrong.

The battery is used to supply energy to an inverter that I run a laptop and cell phone off of. The battery has a multimeter connected to it and my laptop via USB. When the voltage drops to 12.25, the program speaks and at that point I know to connect the battery to my car and charge it.

I think charging is complete once the voltage drops from 14.8-15.0 volts back down to 12.8 and at that point its float charging, then the battery is disconnected and the car is powered off.
Each day since 3/16 the battery is recharged at least 5 times each day. When its cold (less than 60 F), the recharge cycles are more frequent each day. When warm (70F) the battery would last between an hour and an hour and a half. Yesterday, in the same temp (70F) the battery would only last 5 minutes. It was a repeated problem. So I went to exchange it and they happily gave me a new one after saying the battery tested OK. It was not a load test, just voltage and I had the battery charged before arriving.

I think battery life is determined by a number of things and one of them is the charging process. My car has a glass matt battery (Chevy Volt) and this deep cycle is a lead acid battery.
I haven't added any equipment and didn't change anything so I'm curious if I bought a bunk battery or it was a good battery and this new one is going to die in another couple months because I'm doing it wrong or have expectations out of line. I think it should last 1 year, what the warranty covers. Do you think it was my fault the battery to failed so soon?

http://www.oreillyauto.com/site/c/detail/SSB2/27DCM/N0056.oap?ck=Search_deep+cycle+%26+marine+batteries_-1_-1&keyword=deep+cycle+%26+marine+batteries

Mary B

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Re: Deep cycle battery life expectancy. Did I buy a bunk battery?
« Reply #1 on: May 28, 2016, 06:20:14 PM »
That battery at best has 45 amp hour capacity. Not knowing the power draw on your laptop all I can do is guess and say 3 amps when charging it or running off the inverter.  Depending on the inverter you may only have 90% or less efficiency so add in a 10%+ power loss. Then add in the inverter stand by power draw. 3 amps at 120 volts = 30+ amps to the inverter so an hour or two and your battery is at half capacity. Plus that battery is not a true deep cycle... it is a starting battery mainly.

dnix71

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Re: Deep cycle battery life expectancy. Did I buy a bunk battery?
« Reply #2 on: May 28, 2016, 06:50:56 PM »
Discharging to 12.25v is a brutal depth of discharge. Below 12.4v causes sulfation. If you can add water to this battery, then the recharge should go to 15.5 volts for the kind of hard use you are giving it. Check the water once a day and add enough distilled water to keep the top of the plates covered. Only add water after charging and letting it rest a few minutes.

Most traction battery makers rate their products for number of charge cycles, even if the depth of discharge is low. 5 times a day and no lead acid battery made by anyone will last long.

zracer

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Re: Deep cycle battery life expectancy. Did I buy a bunk battery?
« Reply #3 on: May 28, 2016, 07:02:58 PM »
dnix71, I didn't think to check the water since it was so new. Thanks for that suggestion. It sounds like the charging isn't so much a problem, but rather how many times I've drained it to a level that causes sulfating and then recharging it per day.

I've been looking at the Trojan brand, but they are not for sale within over a 100 mile radius from me. Would glass matt work for this case? I've seen the Optima batteries that are $200+, but thought they were overpriced. Maybe I could  get two of these SureStart batteries (the price of one Optima) and that would allow me to drain for 1 hr (to 12.4v) which would increase the battery life from 1.5 months to say 6 months?

Would I gain in recharge cycles by going with a yellow or blue top Optima?
« Last Edit: May 28, 2016, 07:12:53 PM by zracer »

dnix71

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Re: Deep cycle battery life expectancy. Did I buy a bunk battery?
« Reply #4 on: May 28, 2016, 07:30:42 PM »
Optima's are overrated.

AGM's (glass mat) are fragile. You have to be a lot more careful about charging so you don't dry them out, You can't add water without ruining the recombiner. An agm has to be sealed for the gas recombiner to work properly, so if you pry it open to add water, it will void the warranty and never be right again anyway.

There is no cheap way to do what you want, but the best price is probably a couple of 6v flooded lead acid golf cart batteries in series.

Golf cart batteries have much thicker plates and can better withstand the hard charge/discharge you are doing. A couple of Interstate or US Battery branded GC2 size shouldn't cost that much.

zracer

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Re: Deep cycle battery life expectancy. Did I buy a bunk battery?
« Reply #5 on: May 28, 2016, 08:04:48 PM »
You are right, what I want is expensive. $300 plus the $100 mistake I made buying the wrong battery.

I was trying to save energy (cut costs) by leaving my car off and using the inverter off a deep cycle. The Chevy Volts traction battery (360v) keeps the starter battery (12v) charged while powered on, but with the engine off. I think I will cut my loss and just leave the car on and run the inverter off the 12v starter battery. I appreciate your assistance, dnix71.

dnix71

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Re: Deep cycle battery life expectancy. Did I buy a bunk battery?
« Reply #6 on: May 28, 2016, 08:24:30 PM »
There is an inverter kit designed for Chevy Volts, that runs on 12v starting battery. It comes with an Anderson connector and all the wiring you need. You supply the inverter (which you already have).

http://www.evobservatory.com/2015/04/wiring-chevy-volt-for-ac-power-in-field.html

zracer

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Re: Deep cycle battery life expectancy. Did I buy a bunk battery?
« Reply #7 on: May 28, 2016, 08:52:05 PM »
Thats a pretty slick setup. The Anderson connector is nice, was looking for one in town (Bishop, CA) but nobody had one.

I had an idea to build a recharge monitor/management system that turns the car on when the deep cycle battery gets low and then turn the car off once the 12v battery is float charging and disconnect the deep cycle battery. It would be possible by using a few relays and stuff I don't know about yet. You've seen those battery isolator switches, this system would need one of those but a beefy relay kind of deal switchable via low voltage signal. Then a brake pedal position defeat and a remote switch wired in for the cars' power button. Then with software, build an algorithm that signals the brake pedal defeat and toggles the power button switch when the voltage gets low at 12.v4. I think having the battery isolator switch automated would be a good first step and do the brake pedal and power button manually. I think now that I need $300 just for batteries this idea is on the back burner. The car uses a fair amount of juice just being on and that is where I was eyeing the energy savings by turning it off when it isn't needed. But it isn't that much (hundreds of dollars in costs).

thirteen

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Re: Deep cycle battery life expectancy. Did I buy a bunk battery?
« Reply #8 on: May 28, 2016, 09:24:14 PM »
I'm sure you have thought of it but would a small solar panel be workable for you? But that is just a day light item. Just a side idea. 13
MntMnROY 13

zracer

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Re: Deep cycle battery life expectancy. Did I buy a bunk battery?
« Reply #9 on: May 28, 2016, 09:45:21 PM »
I'd like to use solar. The panel would need to be storable inside the car. What do you think would be a good panel to use?

Harold in CR

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Re: Deep cycle battery life expectancy. Did I buy a bunk battery?
« Reply #10 on: May 29, 2016, 07:05:48 AM »

 I'm no electronics tech, so, I will ask a couple of comments here, that MAY help you do a much more efficient system.

 First, assuming you have an insufficient battery system, look up on Ebay, "Nissan Leaf Battery Module". They can be bought for under $90.00 each, (you would need 2) that would give you 15.2V nominal (working voltage) 16.1 V topped off, at 60Ahr each, so, paralleled that gives you 15.2V @ 120Ahr. nearly triple what that lead battery is capable of.

 I have 2 different laptop chargers here, one is 15V output and one is 19V output, both from Toshiba Satellite Laptops. Check your laptop charger to see what it is rated at.

 I tried a voltage test from a USB port and got 5.1V output.

 My theory is, your car charger puts out over 15V (your info), so, that would charge the Leaf double module pack, and, run the laptop directly off the leaf pack and the cell phone off a USB port ? Cheap 12V inverters are VERY inefficient.

 These Lithium batteries have a LOT more capability of powering your system, over a lead battery.

In EV car lingo, "lead is dead". A comparable lead vs lithium battery, you get 3 times the available energy from a Lithium battery and cycling is what these are designed for.

 Thus, you run the car a lot less than needed right now. Lithium modules can last for years, not months, with a little careful monitoring.

 If anything I presented is wrong, I am certain someone on this great site will enlighten me/us.

zracer

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Re: Deep cycle battery life expectancy. Did I buy a bunk battery?
« Reply #11 on: May 29, 2016, 07:33:19 PM »
Mary, did you mean I'm drawing too much from the battery for it to last?

Harold, interesting idea. The Chevy Volt charging system probably doesn't put out enough since it is designed for a 12v glass mat setup. It does peak at 15v at times, but like right now its charging at 14.75v. Is that enough? Not sure on how many amps its putting into the battery.

Harold in CR

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Re: Deep cycle battery life expectancy. Did I buy a bunk battery?
« Reply #12 on: May 30, 2016, 06:27:58 AM »

 You need to check your charging system for max output voltage. It may be possible to add a boost converter to the system to get a minimum of 16V into the Leaf modules, so, 17.5 is probably needed. 

You would also need a way to prevent the 17.5 output from back feeding into the 12V system.

 Like a stated, I'm not an electronics tech, but, constantly see boost converter statements. There are really helpful people here, and, someone should be able to help-explain how to build a boost converter. They are not difficult to build, IF you understand electronics.

Mary B

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Re: Deep cycle battery life expectancy. Did I buy a bunk battery?
« Reply #13 on: May 30, 2016, 04:16:44 PM »
On a 12 volt system the rule of thumb is take whatever the device draws in amps at 120 volts and multiply it by 10 for the battery draw in amps... if this is a 240 volt system the factor is times 5...


Mary, did you mean I'm drawing too much from the battery for it to last?

Harold, interesting idea. The Chevy Volt charging system probably doesn't put out enough since it is designed for a 12v glass mat setup. It does peak at 15v at times, but like right now its charging at 14.75v. Is that enough? Not sure on how many amps its putting into the battery.

Johann

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Re: Deep cycle battery life expectancy. Did I buy a bunk battery?
« Reply #14 on: August 19, 2016, 05:48:14 PM »
I bought a group 27 deep cycle starting battery from O'Reilly auto parts in March and the battery was manufactured in that same month 3/16.

The battery didn't last and I'm looking to find out if I'm doing something wrong.

The battery is used to supply energy to an inverter that I run a laptop and cell phone off of. The battery has a multimeter connected to it and my laptop via USB. When the voltage drops to 12.25, the program speaks and at that point I know to connect the battery to my car and charge it.

I think charging is complete once the voltage drops from 14.8-15.0 volts back down to 12.8 and at that point its float charging, then the battery is disconnected and the car is powered off.
Each day since 3/16 the battery is recharged at least 5 times each day. When its cold (less than 60 F), the recharge cycles are more frequent each day. When warm (70F) the battery would last between an hour and an hour and a half. Yesterday, in the same temp (70F) the battery would only last 5 minutes. It was a repeated problem. So I went to exchange it and they happily gave me a new one after saying the battery tested OK. It was not a load test, just voltage and I had the battery charged before arriving.

I think battery life is determined by a number of things and one of them is the charging process. My car has a glass matt battery (Chevy Volt) and this deep cycle is a lead acid battery.
I haven't added any equipment and didn't change anything so I'm curious if I bought a bunk battery or it was a good battery and this new one is going to die in another couple months because I'm doing it wrong or have expectations out of line. I think it should last 1 year, what the warranty covers. Do you think it was my fault the battery to failed so soon?

http://www.oreillyauto.com/site/c/detail/SSB2/27DCM/N0056.oap?ck=Search_deep+cycle+%26+marine+batteries_-1_-1&keyword=deep+cycle+%26+marine+batteries

This is not a deep cycle battery, it is a starter battery.
« Last Edit: August 19, 2016, 05:56:45 PM by Johann »