AGM vs Gel Batteries

[Adelie]

Originally Posted by Talisker

Thanks for all the tips and web references, certainly some food for thought. I have also learnt how much I mistreat my batteries.

I suppose it all comes down to what sort of use and pocket depth. I have just had the battery (gel I believe) replaced in my Audi A6, 300 Euros plus Ouch!

I have definitely decided that the Gel type is not for me, as I have no intention of replacing my charging system. Over here in Europe the AGMs are about twice as expensive as lead/acid, but I have not read that AGMs are twice as good as lead/acid.

There are some sealed lead/acid on the market so that solves one disadvantage, I guess.

Think I'll just go with the sealed lead/acid, and be done with it!

Thanks again!

For boat use, the only two differences I can see between sealed and regular, is that you can't spill electrolyte from a sealed battery, and you can't top up electrolyte levels in them either. Hence the boat will be cleaner but the batteries will have a shorter life than regular.

[Kettlewell]

Here in the USA I don't believe there are any sealed, maintenance-free deep-cycle batteries. The key being deep-cycle, unless you are just using these for engine starting. Because of the nature of deep-cycling, with lots of power drawn out of the battery and having to be replaced, they will be undergoing a lot more charging than starting batteries. That means more water use in the long run, needing to be replaced, making the maintenance free batteries a bad idea on a boat unless you go AGM or Gell which can't be refilled. Car batteries can be supposed "maintenance-free" because they typically only get drawn down a tiny bit to start the car and then everything runs off the alternator. The very light charging cycle does not use up water in the battery at the rate that deep cycling does.

As to the question about Sams Club's website--they don't show on the website around here either. You have to go and take a look for the batteries branded Duracell. My understanding is that not every Sams Club has them. The one closest to me has quite a selection, including some deep-cycle 12 volts that have the same footprint as a Group 31, but are much taller, packing 150 amps into each one. They are used in mobility devices I believe. They are pricey at around $184 a piece, but they could be a way for some folks with limited room to get more amps in the same space, as long as you can fit the height of the batteries.

[NorthPacific]

2 questions folks.

tropical use, does this have any effect on battery types?

Using boat water maker water can this be used to top battery up?

[senormechanico]

Originally Posted by sy_gilana

We regularly get 6+ years out of our Trojan T105's, and the TCO (total cost of ownership) is the lowest. Friends with expensive batts, were still paying the mortgage on their batteries, when we bought our second set, and now were on our third, (just purchased) With Automatic watering system theyre hard to beat.

For our house system (and I mean HOUSE, not boat) we were given for the cost of the core charge a set of ten Interstate six volt 2200 aH batteries.
They had always been watered with an automatic system, but were ten years old.
As you can imagine, I was suspicious, but they were being offered by my very knowledgeable next door neighbor, a serious cruiser who had gone to power.
He was leaving for Alaska, had no issues with his battery bank, but didn't want to have to buy replacements in the middle of the cruising season (think shipping costs in Alaska).
I went for it, and only had to replace one of them.
I bought one at Costco for $79. and I'm in business.
They're mostly in good condition, a couple are starting to get a little "squishy" but they give me whole house backup for about 24 hours from our sine wave inverter running a big fridge, a freezer, all lighting and computers etc, so what the heck.
I can always recoup my core investment on new ones.

Our boat however, is a whle 'nother kettle of fish.
We have 300 watts of solar, a sine wave inverter, aerogel for fridge / freezer insulation, LiFePo4 batteries and all the juice we can use.
If hot water is needed, turn on the inverter and hot water tank element !!

When the time comes to replace the "House" bank, I'm definitely going with LiFePo4 ! After you get past the initial investment, it's a different world.
It's kinda like getting a boat onto a plane when you've never been there before, it's that good.
The only downside so far, make sure you have your charging parameters firmly met.
Don't let them go too low or too high.
As long as you meet those (read the threads regarding voltage) and you'll never look back!

See the threads on CF about "LiFePo4 for a house bank"

http://www.cruisersforum.com/forums/...archid=2709527

[senormechanico]

Originally Posted by Adelie

For boat use, the only two differences I can see between sealed and regular, is that you can't spill electrolyte from a sealed battery, and you can't top up electrolyte levels in them either. Hence the boat will be cleaner but the batteries will have a shorter life than regular.

Usually in that case, you just need a bigger screwdriver to force open the caps!!

[Adelie]

Originally Posted by NorthPacific

2 questions folks.

tropical use, does this have any effect on battery types?

Using boat water maker water can this be used to top battery up?

Don't know about tropical use but water to top up a battery should be distilled. Push comes to shove you can distill your own with some copper tubing and a teakettle. If you can't get or make distilled, potable water that is not hard or 'tasty' will do.

[Lancerbye]

Originally Posted by NorthPacific

2 questions folks.

tropical use, does this have any effect on battery types?

Using boat water maker water can this be used to top battery up?

Water maker water still has minerals in it so not advisable to use. As has already been said use distilled water. Tropical use can shorten the life of a battery. When I was in the Phillipinnes batteries in cars had to be special tropical batteries or they suffered a short life span. However in a boat, if the batteries are below the waterline, they will be cooler than they would be in a car, so they may not be affected by the heat.

[NorthPacific]

Cheers,

I had hoped that the water maker would get rid of the minerals. Another packable commodity.

[hellosailor]

Audi: Most likely AGM, not gel. The auto industry has been going to AGM mainly because of "hazmat" issues, acid burns to emergency responders, etc.

Tropical use: The local major battery distributor claims the electrolyte in "tropical" batteries is different from "northern" batteries, just how different was less sure, but he said the products sold in each location are physically different to compensate. Cooking batteries and using a temperature compensated charger on them certainly would be more important in hot weather.

[NorthPacific]

My shorepower charger has settings for temperature. Crap. Most of the Pacific Operates on 240 so that means I have to buy a new charger.