Marine battery for camper trailer?

Submitted: Sunday, Jun 01, 2014 at 16:24
ThreadID: 108046 Views:2580 Replies:3 FollowUps:3
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Hi All

I have been considering the use of a Supercharge Seamaster Gold (maintenance free) in my trailer instead of an AGM (to save a few $) however my research has led me to believe I may have difficulty charging it because it is a calcium type battery.

There has been a fair bit written bagging calcium deep cycle batteries claiming they need around 15 volts to charge properly.

I really have not been able to find out what a Seamaster requires however I did read on a boating forum that 14.9 volts was not uncommon on an outboard alternator.

The fact it is also a start and not a true deep cycle may mean it is more accepting of charge?

I am getting around 13.8 volts in the trailer after about a 1/2 hr drive compared to about 14.1 volts at a start battery.

With regard to AGM's it would seem they will accept a charge more readily however their specifications seem to stipulate a relatively low current of around 25 amps which I am sure could be exceeded in my set up.

It seems I can't win either way. Can anyone please put me on the right track.

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Reply By: HKB Electronics - Sunday, Jun 01, 2014 at 17:08

Sunday, Jun 01, 2014 at 17:08
Depending on the make and model of your car you could fit one of my booster diodes to give you a higher charge voltage.

The battery should charge ok at the higher voltage but I have read of a few people having issues with the supercharge batteries.

I would go for something like a Marine pro but exide have changed the name recently so not sure if they have changed the battery itself would pay to check.


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Follow Up By: HKB Electronics - Sunday, Jun 01, 2014 at 17:12

Sunday, Jun 01, 2014 at 17:12
Sorry missed the 14.1V at the cranking battery, booster might lift the battery voltage a bit high, depending on the temperature ambient temperature when you measured the 14.1C

Other option apart from a different battery would be a DCDC charger with a calcium battery setting.


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Follow Up By: Peter T9 - Sunday, Jun 01, 2014 at 17:24

Sunday, Jun 01, 2014 at 17:24
Ok Thanks Leigh

It might be simpler to just get an agm for now, see how it goes and maybe a dc to dc later on if needed.

The strange thing with my setup is I just replaced the charge cable which was 6mm automotive twin core to 13mm squared and didn't see any improvement in voltage drop.

I am sure it will carry more current though.

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Follow Up By: HKB Electronics - Sunday, Jun 01, 2014 at 17:51

Sunday, Jun 01, 2014 at 17:51
The voltage drop is dependent on the current, the heavier cable will give less drop for the same given current.

Keep in mind also the more discharged the battery is the less voltage you need to pumd charge into it, it is only when you approach the 80% SOC that higher charge voltages become an advantage.

Regarding calcium batteries, it was thought when they first appeared on the scene that using calcium batteries in normal charging system would reduce their life, it would seem this is not the case but then that might be just what the battery manufactures want you to believe.

Most modern batteries have a calcium content, the only one though I have read of people having issues with though are the alrounder?

I have an alrounder though in my KIA but have not had any issues with it though the charge voltage is around the 14.4V mark. I have read of others though with similar voltages though that have had to remove the alrounders due to problems?


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Reply By: The Bantam - Monday, Jun 02, 2014 at 19:33

Monday, Jun 02, 2014 at 19:33
lets clear up a few mentioned above, almost every sealed battery has calcium in it plates.
Calcium and a modified electrolite is used to reduce also improves just about every other performance factor in a battery.

the problem of calcium charge resistance can occur when the battery is cycled too deeply or other wise neglected.

Under this situation it may need a kick in the guts with 15 ish volts to get it back to charging.

otherwise there is no problem at all running them at a lower ( read normal) charging voltage...though they will tolerate voltages in the 14.5 ish volts very well.

I run supercharge golds in both starting and aux positions.....before I replaced the alternator they where charging fine on 13.8 volts......they now charge just fine on 14.2 volts.

there is a lot of...frankly BULL#@!% beeing peddled about, this or that battery not charging from this or that charger......frankly the battery manufacturer documents do not support this view.

The super charge gold is not a "true deep cycle battery"..whatever that means......but they do have pretty good deep cycle tolerance....note the word tolerance.

remember you can buy 2 supercharge golds for the price of a single AGM...AND hammer the charge into them need for a DC to Dc charger to limit the current.

As for outboard charging systems being 14,9 volts........yeh well some outboard charging curcuits are very crude and unregulated......both my mercury 30Hp and my evenrude 60Hp both charge at 13.8 volts..regulated.

These and batteries similar to them are designed to work with normal every day charging systems.

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Reply By: Member - Phil G (SA) - Thursday, Jun 05, 2014 at 22:19

Thursday, Jun 05, 2014 at 22:19
Century Marine batteries are one of the best quality/value options for an aux battery.
Can get the 100Ah N70ZM for $153 from this place in Adelaide.
No affiliation - its just where I buy my batteries.
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