North Australian FISH FINDER TM forums

Have you had a look into Lithium Ion ? Do some research.........AGM is old tech.

buzzdog wrote:Ah gotcha, I don't mind paying the extra money for a quality product.
I believe I found the battery Old Mate was talking about.

http://pages.ebay.com/link/?nav=item.vi ... 71&alt=web

This is the battery I bought originally. I wouldn't recommend them. Light both in weight and lifetime.

From memory the mob at Yarrawonga sell the FullRivers. Outback Batteries???

Basstad wrote:Have you had a look into Lithium Ion ? Do some research.........AGM is old tech.

They are the way to go, 100% Depth of discharge capable and half the weight of AGM. But at $1500 each, it's gets exxy if your running a 36volt setup

http://www.batteriesdirect.com.au/shop/ ... 2-120.html

ken_dog wrote:

Basstad wrote:Have you had a look into Lithium Ion ? Do some research.........AGM is old tech.

They are the way to go, 100% Depth of discharge capable and half the weight of AGM. But at $1500 each, it's gets exxy if your running a 36volt setup

http://www.batteriesdirect.com.au/shop/ ... 2-120.html

Did not even realise they made Lithium-Ion for this type of application.

But at $1500 each, it's gets exxy

Plus the cost of a safe to lock them up each night.

I hear lithium fires can be a bit pesky also.

buzzdog wrote:

ken_dog wrote:

Basstad wrote:Have you had a look into Lithium Ion ? Do some research.........AGM is old tech.

They are the way to go, 100% Depth of discharge capable and half the weight of AGM. But at $1500 each, it's gets exxy if your running a 36volt setup

http://www.batteriesdirect.com.au/shop/ ... 2-120.html

Did not even realise they made Lithium-Ion for this type of application.

It's not a traditional Lithium-Ion (cobalt oxide) its a Lithium Phosphate (iron phosphate) which are significantly safer

but yes, would require spending much more than my minn kota is worth in just batteries, no thanks - i'll keep my wet cell deep cycles thanks!

Im with you nathan two wet cell deep cycles and you cant go wrong. Cheaper and easier to deal with in the long run rather then having to buy specialist charge set ups and the intial outlay for agms. I can buy four of the type I use for similar money
Depends what your after really I suppose

While there's some heat on the topic, can someone give me some advice on how to take care of and charge my new AGMs correctly to ensure they last the years you'd expect?

I have two in the boat. The first is the starter for the outboard and runs all the accessories (I don't really like how it's set up for both), the second purely runs the Minn Kota. At the moment, they are only hooked up to the VSR in the boat. The VSR is set to 1&2 where ever I'm headed.

Two main points I'm confused about are, 1. will the batteries charge correctly just through the VSR while I'm motoring around (e.g. will they overcharge) and 2. what's the best way to ensure they maintain their life while the boat is parked up at home?

Correct way of charging is using a dc to dc charge kit it basicly drops the amps down to a level the agms like. Othwrwise they will say there full but only be at half charge really as the plates need time to recharge over time and most outboards charge too fast.
As far as I know most agms dont have a starting capacity they are soley for deep cycle use so just check yourparticular batt is ok to use as a start batt.
When at home you should always recharge fully befote heading out again using something lile a ctek. Simply buy another anderson plug same as on what on the wiring to batts and put on charger then simply plug it in when you get home.
Other thing is you really should have a dual.batt isolater used in conjuction with the vsr. That way if main.batt fails as its hooked up to the accesories or whatever reason hopefully you can link them and have enough in minn kota batt. I personally dont use vsrs anymore.

Most DC-DC inverters have VSR functionality anyway, so get yourself the inverter and swap out the VSR.

Alternators will not fully charge ANY battery anyway so battery life with an alternator is reduced compared to that if charged with a multistage charger. However, an alternator is a convenient charge method and reduced life is the price you pay for convenience.

Deep cycle batteries and cranking batteries have different internal construction.

Cranking batteries have thinner more porous plates to maximise plate area exposed to the electrolyte be it acid bath (wet cell) or paste (AGM). Supply lots of current for short periods. Sometimes called shallow cycle batteries.

Deep cycle batteries have thicker plates with not as much plate surface area exposed as they are only required to supply lower current but for longer periods than a cranking battery. Thicker plates means heavier.

Deep cycle batteries will act as a cranking battery but need to be about 20% larger in capacity to get the current amps up for cranking purposes. But it doesn't work in reverse.

A cranking battery will have very much reduced life if used in a deep cycle application. Its plate construction is different. You'll get away with it for a while as the battery deteriorates but it'll fail before its time.

A cranking battery will tell you CCA and RC with RC (reserve capacity) being of interest if thinking about using a deep cycle as an alternative starting battery. The engine manufacturer will nominate a CCA for the engine. That'll also give you the reserve capacity. Lets say 700CCA and 120 reserve capacity.

As a rule of thumb an amp/hrs equivalent capability is approx. .6 of the reserve capacity so the 120 RC will translate to about 72 ahrs.

But a 72 ahr battery will not be able to supply adequate cranking current so you need to go higher in ahrs with a deep cycle to get sufficient cranking amps.

20% higher in ahrs is what's considered necessary so you'd be able to get away with a 90 ahr capacity deep cycle battery if used as a cranking/starting application. As cranking is actually shallow cycle (its only cranking for short periods of time) the depth of discharge of your deep cycle will be under the 50% ideal mark.

Don't try the other way around though (using a cranking battery as a deep cycle application).

Some good practical advice here from Jabsy and Scottie.

As said above if you want to get the most out of your batteries you need to charge them correctly. I use a Redarc BCDC charger in my boat and it does the job perfectly. Quality gear (fully sealed) designed and made in Australia and great service - they're happy to help with any questions.

The alternator in my boat is rated at 25amps so I have gone with the 20amp charger BCDC1220. This works well and means there are usually a few amps left over for the running and charging of the start battery (if not the Redarc will shut off for a while to allow the alternator to top up the start battery). http://www.redarc.com.au/products/produ ... tart-bcdc/

I was originally using the 25amp redarc BCDC1225 and had a few issues with the start battery missing out too often and the charger constantly switching on and off (only when AGM requiring the full 25amp boost charge). So I found choosing a charger that is at least 5amps less than the rating of the alternator fixed the issue and has worked for me.

You will still need to have a good 240V battery charger at home as well to charge and maintain your batteries while in storage between fishing trips. I use a solar panel with smart charger for this. If you are able to use the 25amp redarc BCDC1225 in your boat it has an extra input for a solar panel to charge while in storage, unfortunately the 20amp Redarc charger I have doesn't have this feature.

Wow, so much great information. Thank you Scottie, jabsy, ronje and maxpower. Off the back of your advice, I think there might be some plans to change a few things.

ronje wrote:A cranking battery will tell you CCA and RC with RC (reserve capacity) being of interest if thinking about using a deep cycle as an alternative starting battery. The engine manufacturer will nominate a CCA for the engine. That'll also give you the reserve capacity. Lets say 700CCA and 120 reserve capacity.

As a rule of thumb an amp/hrs equivalent capability is approx. .6 of the reserve capacity so the 120 RC will translate to about 72 ahrs.

But a 72 ahr battery will not be able to supply adequate cranking current so you need to go higher in ahrs with a deep cycle to get sufficient cranking amps.

20% higher in ahrs is what's considered necessary so you'd be able to get away with a 90 ahr capacity deep cycle battery if used as a cranking/starting application. As cranking is actually shallow cycle (its only cranking for short periods of time) the depth of discharge of your deep cycle will be under the 50% ideal mark.

The engine is a Yamaha F60 with a minimum requirement of 380 CCA (502 MCA) and Reserve Capacity of 124 minutes. I have two Deka Intimidator 8A31DTM batteries, http://www.federalbatteries.com.au/8A31DTM/, 800 CCA, 105 Ah and 190 RC.

Using the rule of thumb, it looks like they should be fine for starting/cranking duties. If I'm wrong, please do let me know though.

maxpower wrote:As said above if you want to get the most out of your batteries you need to charge them correctly. I use a Redarc BCDC charger in my boat and it does the job perfectly. Quality gear (fully sealed) designed and made in Australia and great service - they're happy to help with any questions.

The alternator in my boat is rated at 25amps so I have gone with the 20amp charger BCDC1220. This works well and means there are usually a few amps left over for the running and charging of the start battery (if not the Redarc will shut off for a while to allow the alternator to top up the start battery). http://www.redarc.com.au/products/produ ... tart-bcdc/

I was originally using the 25amp redarc BCDC1225 and had a few issues with the start battery missing out too often and the charger constantly switching on and off (only when AGM requiring the full 25amp boost charge). So I found choosing a charger that is at least 5amps less than the rating of the alternator fixed the issue and has worked for me.

You will still need to have a good 240V battery charger at home as well to charge and maintain your batteries while in storage between fishing trips. I use a solar panel with smart charger for this. If you are able to use the 25amp redarc BCDC1225 in your boat it has an extra input for a solar panel to charge while in storage, unfortunately the 20amp Redarc charger I have doesn't have this feature.

Looking at the Owner's Manual for the F60, the "maximum generator output" (I'm going to assume they are referring to the alternator) is only 16 amps. So even the Redarc BCDC1220 or CTEK D250S Dual would be overkill and wouldn't work in my configuration. I only base this assumption on your experience of requiring a charger that is at least 5 amps less than the rating of the alternator.

The only other DCDC charger that I could find that is 5 or more amps less that the alternator rating is the Redarc BCDC1206, http://www.redarc.com.au/products/produ ... y-charger/. It looks to be Redarc's most basic charger with limited capabilities. Does anyone know of any other DCDC Charger suitable to my configuration?

As for the 240V charger for when at home, I assume something along the lines of a CTEK MXS25 or M200/300 would suffice?

ken_dog wrote:

Basstad wrote:Have you had a look into Lithium Ion ? Do some research.........AGM is old tech.

They are the way to go, 100% Depth of discharge capable and half the weight of AGM. But at $1500 each, it's gets exxy if your running a 36volt setup

http://www.batteriesdirect.com.au/shop/ ... 2-120.html

You don't need to pay that much........Try a website called "Basicly Natural The Back Shed". or "Live By Nature Drive By Nature".......100AH for just over $600.......they do Solar off the grid stuff and will make you up a battery to suit your needs.