Heavy Duty Truck Battery OK for Boat ?

[Copprhead]

My new boat comes with a heavy duty truck battery as service battery (Banner SHD 635 44 - 135 Ah). I'm wondering how this battery will stand the regular discharging (hopefully _just_ 50% but about other day) and charging with high current. My alternator puts out 115 A max, and the mains charger 45 A. The battery manufacturer recommends charging at 13,5 A.

Should I replace this battery right away and not even bother? (The capacity is also pretty poor, we want to live on the boat - 2 adults - and so far have not decided on buying solar panels).

[daddle]

Use it until it's a problem, then get a deep cycle version.

[Aussiesuede]

That's a starting battery. It's not designed for sustained loads (that's why the amp/hrs are so low). For 2 adults living aboard - 135ah simply isn't going to cut it, even for ultra-minimalist usage.

[troppo]

Copprhead, what's ya plan for charging up the battery? Ya mention a mains charger and boat motor but say no solar panels. If ya tied up in a marina, the mains charger is useful. Away from the marina, extension cords to the power station can only go so far.

The house battery on my boat is a 75 ah marine starter/storage one, but only because that's what I got with the boat. I use a 20 w solar panel which I move around the deck to keep both batteries charged. With north Qld sunshine, it is more than enough to run my small load of lights, radio, fan sometimes. But that is only for now.

My plan is to first replace the starter motor battery and put in a smart isolator so it gets priority for charging. That is a little insurance towards being able to get the motor started everytime. The retired starter battery will be put with the storage battery as they are the same and I will use them as house batteries until they bust or I win the lottery. That will give me 175 ah storage.

Eventually, I plan to have a deep cycle storage capacity of 200 ah with maybe 250 watts of solar panel. The motor will charge the starting battery and excess go to the house batteries if needed. The solar panel overflow will go to the start battery if needed, all automatic. This system should fit my life style of spending a few weeks every few months cruising the quiet places and the rest of the time having it closed up somewhere. Gadget wise, I will add a small fridge/freezer and extra fan or two to make the tropical nights more bearable. But that is my plans.

So, to suggest an answer to your question, if you are spending most of your time away from a marina and have the money, replace the battery with a deep cycle one (or several) which will cover your needs and think about solar power as either a way to top up your battery if doing much motoring or a bigger solar power system to provide practically all of it if anchored in one spot.

On the other hand, if your power load is not too high, you may like to keep the old battery for a time but invest in solar technology which down the track you can connect to a new deep storage battery. In my experience, which is minimal, of living on the boat a few weeks at a time, I have found by having a go with what was there, as inadequate as I originally thought it was, I have had better ideas and insight into what will actually work as a solution.

[Copprhead]

Thanks for the replies so far.

Our usage pattern: We won't be minimalists with respect to use of electricity: The boat has a fridge and I will need to use my notebook computer for some remote work. I was estimating our power consumption to be around 60 Ah/day (on anchor).

Charging: I was thinking about going to a harbor once or twice a week (charging batteries, water, shopping, laundry). In between could charge with the engine.

Solar: Have thought a lot about solar panels but not sure how to mount them. I don't want to have to move them around all day, ideally they should be installed once and then forgotten.
I thought about mounting them directly onto the bimini (least shade, not in the way) with some extra rods, but then I won't be able to fold the bimini any more. Or add a separate construction that goes around and above the bimini and mount the panels onto that.

Of course instead of spending xxxx EUR on a 400 Ah deep cycle battery bank I could spend xx EUR on a solar panel + regulator and xx EUR on a 200 Ah battery bank, since the solar panel(s) will be able to provide most of the power needed. And/or get cheaper (non deep cycle) batteries since they won't be deep discharged very often. Does this make sense?

[Artif]

If it came with the boat then use it.
50% discharge is too much to ensure longevity of your batteries, even deep cycle batteries.
When you design your system work out your total estimated consumption and design it on a 30% discharge because you will end up using more than you think.
You don't state your location but if your in the higher latitudes of Europe then solar probably isn't the best option.
Cheap batteries are cheap batteries, for a domestic situation you will replace them often, quality deep cycle batteries have thicker plates hence the higher price.
And don't be tempted by multi purpose batteries they are neither one or the other.

[Copprhead]

Artif: Just updated my profile, we are crusing in the western mediterranean. So lots of sun.

30% discharge and 60 Ah consumption (+ margin) => You think 200 Ah would be ok then? (I guess only if charged daily?)

[Pete7]

Originally Posted by Copprhead

Artif: Just updated my profile, we are crusing in the western mediterranean. So lots of sun.

30% discharge and 60 Ah consumption (+ margin) => You think 200 Ah would be ok then? (I guess only if charged daily?)

That sounds better and close to our numbers too. We have 2 x 110 Ah batteries for the house bank. Our consumption is lower and we get back 10 Ah from solar at the moment but still need to run the generator every other day to top the batteries off with a smart battery charger.

I think you will be disappointed if you try to use the engine without a smart charger. Here are a couple of links worth reading I have no connection to Sterling but find his articles common sense.

Sterling Power Products: How effective is advanced battery charging on a battery and can it damage the battery?

Sterling Power Products: What is the best battery to use for an auxiliary charging system?

Pete

[Copprhead]

Pete,

I'm familiar with the Sterling products and had originally planned on getting an advanced regulator. But the engine on my boat (VolvoPenta D1-20) already has an improved regulator and alternator: 30 amps at engine idle, 115 amps max and a sensor cable to connect to the service battery so it gets charged well - all according to VP, will have to see how it works in real life, might fit an advanced reg later if it's not good enough (but will then wait for instructions from Sterling on how to connect it to the new VP alternators).

[Pete7]

Ah good, that's better than the traditional alternator, but still means running the engine without any load which isn't good for a diesel.

The other thing worth doing is to fit one of the monitoring gauges to count the Ah in and out of the batteries plus it also shows what each appliance uses as you switch them on. We have the sterling but there are others like Victron and Merlin.

BMV-600S and BMV-602S - Victron Energy

There is also Merlin, which doesn't count Ah, but works off the voltage and some clever eletronics

Battery Monitoring

Pete

[Copprhead]

I was looking at the Philippi BCM 1 and like it. It has a very low power consumption (especially compared to the Sterling): < 1 - 2.5 mA

http://www.info.philippi-online.de/BCM_gb.pdf