Replacing house batteries

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jim
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Replacing house batteries

Post by jim »

Eileen and I recently purchased a 2006 PDQ and our house batteries aren't holding a charge and are using water. They are 6 year old Trojan 145 plus deep cycle 6v batteries in series and parallel ( a total of four batteries). I'm not having luck arranging for the local yard to replace them, so I'm contemplating replacing them myself. Other than replacing a single car battery and knowing to remove the wire from the black negative ( ground) terminal first, I have no experience or knowledge of how to approach this project. Is there a you tube video or can anyone explain how to go about replacing them so I can do it myself? Is this a project I should let the experts handle and see how it's done before tackling myself? The boat also has solar panels.
Eileen and Jim McKay, "Eagle Ei"
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Re: Replacing house batteries

Post by AMCarter3 »

Jim,

We're facing the same issue on our 2006 PDQ Powercat. we bought the boat last April. The 4 "Golf Cart" deep cycle batteries were new at that time. However, we quickly found they do NOT have enough amp power to allow us to operate at anchor for more than 24 hours. And it was taking 6-9 hours to recharge them to 85%.

Our goal is to be able to be able to operate at anchor for at least 3 days before being required to start an engine to re-charge AND be able to recharge the batteries within 3 hours (up to 85% plus). To accomplish this, we contracted with a local marine electronics company that specializes in doing power management upgrades. Here's what going into our boat literally this week:

1) 4 - 220 amp AGM Northstar batteries (3 are going into the existing battery compartment; the 4th is going into the dead space under the battery compartment between the two berths)
2) 1 - Sterling 4-step progressive charger (this will also be mounted in the dead space under the battery compartment between the two berths)
3) 1 - 180 amp Electromaax Alternator (mounted on the Port engine to enable heating fresh water when charging)

This project includes re-placing a lot of the corroded heavy duty 4/0 power cables. Note that the tech crew found a LOT of loose, corroded (scary corroded) connections when they were planning the project. The project is costing a lot, but we think it is a necessary and worthwhile investment to be able to use the boat the way we want to use it. Hope this helps you.
Mac Carter
2006 34' PDQ PowerCat "All Heart"; MV 98; twin 100 HP Yanmars
Home Port: Bellingham WA 98229
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Re: Replacing house batteries

Post by duetto »

hi,

it isn't hard but there are a couple of gotchas.

first, you need to decide if you're just going to do an exact replacement (easiest) or 1) switching brands 2) and/or switching to agm type of battery. i believe the pros and cons of wet cell/flooded vs agm is discussed on this forum and if not just google it.

if you do an exact replacement just make a simple drawing of the existing batteries pos & neg terminals and which wires connect to each pos & neg terminal. then remove the old and install the new MAKING SURE THE PHYSICAL ORIENTATION of the new battery matches the old.

if you switch brands the orientation of the pos & neg terminals may not be the same as the trojan's so your wires may not work. if you choose to switch brands bring your drawing to the battery store and make sure they match.

one last thing. i believe the trojan's have one of the highest amp-hour capacity, so if you switch brands check this and make sure they are close. say within 10-15 amp-hrs.
john & diane cummings
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Re: Replacing house batteries

Post by jim »

Thanks Mac and John. Is there a recommended order to removing the wires? I will turn off everything at the electrical panel and turn off the combiner under the helm seat. Jim
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Re: Replacing house batteries

Post by wrnole »

Jim,

My wife and I replaced our 5 Lifeline AGM batteries (factory installed) with no major issues. We did a drawing and also took photos of the batteries and connections. We had to remove four of the batteries to get to the fifth battery. Your process should be easier. Just turn your battery switch off and I suggest you apply a protective coating to the battery posts to help prevent corrosion. Good luck.

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Re: Replacing house batteries

Post by AMCarter3 »

Jim,

Be sure to disconnect from shore power too before working on your batteries. I don't think there is a set order to removing the battery cables.
Mac Carter
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Re: Replacing house batteries

Post by duetto »

also shut off the inverter/battery charger before you start.
john & diane cummings
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Re: Replacing house batteries

Post by jim »

Thanks guys. Jim
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Re: Replacing house batteries

Post by jim »

9.18/16 I followed your suggestions and with your encouragement successfully replaced the four Trojan T145's with identical batteries for $730. rather than the $2,200. quote from the marina. Thanks guys.
Now if I can just find where to turn on the Tristar solar panels. I found the control box hidden in the space between the berth cabins, but can not find a circuit breaker, fuse or on-off switch. Jim
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Re: Replacing house batteries

Post by thinwater »

If the solar charge regulator does not have an "off switch," just throw a towel over them. This is mandatory tip when working on the panel side of the wiring.
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Re: Replacing house batteries

Post by AlanH »

We have decided to replace our house batteries so these posts have been helpful. The current batteries are 4 standard wet cell 6 volt, 216 AH golf cart batteries. We don’t spend much time anchored out so new batteries of similar capacity will do for us. We have decided to replace them with Trojan AGM batteries of similar output http://www.trojanbattery.com/pdf/datash ... Sheets.pdf. They are a bit pricey, $1,183 for the four of the including tax. I am not a battery expert but I will like the convenience of not have to water the batteries.

I have run across a couple of issues though. We have the PROsine 2.0 and it is supposed to be reconfigured if the battery type or size is changed. It turns out the last time the batteries were replaced that was not done. It was configured for Gel batteries. I am setting to AGM. Not sure how it may or may not have affected things but it may be worth others checking out their settings.

Now for a question. The PROsine has a setting for battery size. It is set for 440 AH. There are 4 batteries at 217 AH each. It would seem on the surface the 440 is only half what it should be? The batteries are wired in series and parallel and I have no clue if that has an impact on the correct setting.

Any help would be appreciated.
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Re: Replacing house batteries

Post by James Power »

Hi AlanH, if the individual batteries are 217 AH at 6 volts and wired up in series parallel to get 12 volts then the whole bank would have a 12 volt capacity of 434 AH. Make sure all the terminal connections are clean and tight, the prosine is set to AGM, and all should be good. On a side note, when working around large battery banks exercise extra caution to prevent a short circuit. Covering the exposed battery posts until the final connection is made and a protective cover is applied, is a safe way to go. Hope this helps. James
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Re: Replacing house batteries

Post by AlanH »

James,

That answers my question and I will be very cautious during the job.

Thanks a lot for the help.

Alan
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Re: Replacing house batteries

Post by rhumbline2 »

On Rhumbline, I replaced the smallish wires to the refrigerator, with some very large ones. This made a big difference - allowing the fridge to run for much longer times between charging the batteries.

James Mills
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Re: Replacing house batteries

Post by duetto »

hi james,

where did you start the bigger wire, at the breaker?

john (duetto)
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