Solar plus 240 volt charger plus vehicle charging ??

Actually the Arrid twin charge is not a smart charger. It gives a constant output voltage. My one gave an output of 14.4 V. I attribute the premature demise of the first battery in the current van to the twin charge (less than 12 months service.)

I replaced the battery in late 06 and disconnected the twin charge. In April 08 I replaced it with a RanOx booster which is a smart charger. For the last two years I have had all three chargers connected in parallel to the battery and the battery still gives good service.

PeterD

Battery use a theory called "Arrhenius equation" to work.

A battery is just a glorified chemistry set.

Another good thing to look at is "thermal Run Away".

I've never seen an AGM Battery Manufacture recommend more than 0.3 C (30 amps for a 100 amphour battery) for long battery life.

Which manufacturer recommends 0.75 ?

Most of the time we will charge 75 to 100a/h battery at maximum 25 amps (unless specs say different).

For example if you use Optima battery's they only recommend 10 amps max, meaning most people who use them have been over charging them. You can rapid charge them at any current up to 15.6 volts as long as the battery temp stays below 52 Deg.C......this cancels most under bonnet applications out.

Mike ,

Who , apart from you , said anything about manufacturers recommendations ??

Please read this --- Notice the two words CAN in there !

AGMs on the other hand can be charged at upto 75% of their 20 hour aH rating
so a 100 aH AGM can accept upto 75 Amps of charge ...

The article I read --here

A MAJOR issue with AGM batteries. AGM batteries will accept, in real life, a charge rate of 75% or more of their AH capacities. This means, a 200 AHr AGM battery can be charged at 150 Amps with no problem. The average cruiser will have 400 - 600 AH capacities, but I know of few, if any, alternators capable of putting out 300+ Amps. Another good point about the AGM's is that they will be quite happy with a charger that does not meet this parameter, they will just charge slower, unlike Lead Acid batteries which will loose capacity if charged at a lower than proper rate. BUT, AGM's will suck in everything they can get ahold of!

Cheers

Steve

Also I CAN discharge a 12 volt battery down to 6 volts - but I certainly wouldn't write that here, without making it very clear what effect this will have on battery life.

Steve, you can charge any battery with any amount of current as long as the temperature of the battery is controlled.....this is usually around 50 Deg.C max.

Once the temperature starts to rise the chemical reaction in the battery changes, this is called the "Arrhenius equation" and is based on chemistry, the other thing to watch is "thermal run away" once the battery is starting to charge the temperature increases to a point where it will take off and with higher temperature the chemical reaction changes generating more heat, when this happens it is very hard to control the temperature.

A battery will only accept most of the charge within roughly the first 60 minutes and as the internal resistance changes so does the charge rates from bulk charge to trickle charge.

Most 3 stage chargers have a bulk, absorption and float charge, bulk charge is usually controlled by a timer system and will in most cases deliver up to 80% of the charge with absorption and float charge sensed of the battery.

It is up most important to read the charge specs of any battery before charging if available, if not go with the 25% rule and you will be pretty safe.

"AGMs on the other hand can be charged at upto 75% of their 20 hour aH rating
so a 100 aH AGM can accept upto 75 Amps of charge ... "here

Really love the fact that this quote came from a site called "Wishful thinking" :-)

Lex ,

I think the vessel's name is "Wishful Thinking" not the website ..

www.bitwranglers.com is a boating site ....and hopefully they know

a little bit about batteries an 'at !! LOL

Cheers

Steve

"Wishful Thinking
My web site for sharing experiences and adventures
living aboard a blue water sailboat."


A battery expert hey?

A quote from one of his pages doesn't instill much confidence.

"After nearly 1.5 years of intermittent charging problems, we finally got it. "

Lex ,

Did anyone call him a battery expert ? Only you ...

I would have thought that even you would agree that a person living on a sailboat for several years

might just might " know a little bit about batteries an 'at !!"

Lets put this one to bed shall we -

Cheers

Steve

What is their current price? are they still close to $1500?

I think a RanOx is still under $400. That is all he needs to add to the current equipment and he can leave them all connected.

PeterD

The Ranox is a very good product and has many advantages but we are having a few issues with heat and the Ranox's switching off at the moment.

The Ranox is just under $500.00.

The Retail for the RedArc is just under $1500 but when we sell them we through some other stuff in so your paying a lot less then that.

Thats about all I can say as it's not fair on the paid advertisers on this forum to push what we do.

I'm not on forums to sell.

But I can help you out with any questions.

Can't spell today...

Should be

"The Retail for the RedArc is just under $1500 but when we sell them we throw some other stuff in so your paying a lot less then that.