Portable battery

[yoot]

Bit if an update, I now have a Patrol as well (2010) and fitted a 120AH AGM with dual battery isolator, I get about 5-7days out of the waeco 60L without driving which is about 3 times more than I need, so now I am running 12v flouro etc to get my use out of the battery.

I sold the waeco 36AH on ebay for $50 more than I bought it for and put that money towards the big dual battery setup.

[Deeptank]

Originally Posted by yoot

Amazing that only cost $500, I can't even find a DC-DC that chargers at 20-30A/hour for under $500. Yours must be a 10A Yeah?

Yep, the Engel 12v->12v is 10A. I bought it from Ray's Outddors for $89 or something like that... They seem to be $140-ish these days.

It's enough to top up the battery, but for 2-4 day trips I don't even bother as the battery is just fine without charging - I usually come home with it still reading around 12.0V.

Redarc and Projecta have some beefier units, so if I need more charging amps I might look at them or a folding 100W solar panel. I hate gennies... I go camping to get away from the noise - not to take i with me. Sure, the Honda gennies are pretty quiet, but still...

[Deeptank]

Originally Posted by yoot

Yeah thats too slow, I would think a 20-30A charger would be more appropriate for camping, especially if you only drive for 1-2 hours a day.

But still, I can't see how a portable 120AH battery system that can recharge in 2-3hours from flat can cost so little, AGM Batteries make up 80% of the cost, and thats if you just use a relay (which a quality one would cost $150 for example). I'm sure the box and electronic bits are only $50 but still thats a good $500 right there, a 30A DC-DC will add another $450 at least. I'm just amazed this bloke can do that for so little.

Maybe there are cheaper brands out there that are just as reliable?

The Pulse Hyper (110AH RC100) is around $450,- but I got mine from Battery World for $349,- a couple of years ago. I love haggling...

The battery is still performing as well as the day it was bought!

[squizzytaylor]

Originally Posted by grit

I made my own.
Its 85Ah (700CCA) fully sealed deep cycle Calcium / Calcium battery fitted into a plastic case with an Anderson plug to charge from 6mm cables located under back seat. Runs 52L Fridge / Freezer set to -4C for at-least 4½ days (Min.) when isolated (away from vehicle). Has 2 marine quality rubber capped lighter plugs fitted to lid & it can be switched to assist primary battery start motor if need be. Use it for all lighting, shower, and Freezer requirements as well as running an inverter for laptop. With a short run in the vehicle every few days its good for at-least 4 more. Food stays frozen permanently, camp site is always very well lit and those long hot showers at the end of a dusty hot day keep the women happy.

Battery $90
Box $12
Plugs $10 each
6mm wire, fuse, lugs (approx. $20)

Note: Vehicle wiring (Min. 6mm for up to 5M), Isolator(use Redarc), Anderson Plugs, connectors, etc. will cost about the same again.

Where the hell do you get an 85ah calcium for $90???

Ill take 3

[yoot]

Originally Posted by Deeptank

Yep, the Engel 12v->12v is 10A. I bought it from Ray's Outddors for $89 or something like that... They seem to be $140-ish these days.

It's enough to top up the battery, but for 2-4 day trips I don't even bother as the battery is just fine without charging - I usually come home with it still reading around 12.0V.

Redarc and Projecta have some beefier units, so if I need more charging amps I might look at them or a folding 100W solar panel. I hate gennies... I go camping to get away from the noise - not to take i with me. Sure, the Honda gennies are pretty quiet, but still...

That's fair enough, I chose to just go a 40A charge using a 120A dual battery isolator. I just remove the battery (all 30kg) and plug in to a 3 stage charger when not in use.

But a 120A battery barely has a dent in it when running a fridge and lights with a short drive every day.

[Vegetoast]

Dont you guys find that the AGM batteries take along time to charge?
I got rid of mine cause they couldnt keep up with the fridge and the starter on the car was always sluggish, Now I'm back to the standard batteries I dont have those problems anymore. One of my AGM batteries has got some good use in my ride on mower cause it sits around alot. I guess also we camp alot and use the batteries all the time.

As far as I know If you charge your agm battery or any battery at a rate more than 10% of its copaciticty continuously your cooking it. 30-40 amps constant cant be good.

Great work Deeptank, I like your box!

[Vegetoast]

Originally Posted by squizzytaylor

Where the hell do you get an 85ah calcium for $90???

Ill take 3

Try your local autolec, If your power hungry like me you wont want them anyway.

[Deeptank]

Originally Posted by yoot

That's fair enough, I chose to just go a 40A charge using a 120A dual battery isolator. I just remove the battery (all 30kg) and plug in to a 3 stage charger when not in use.

But a 120A battery barely has a dent in it when running a fridge and lights with a short drive every day.

When I get home, I take the battery box out of my storage unit in the back of the Prado and charge it with a 7A Ctek, which usually takes overnight, but that's cool.

[Deeptank]

Originally Posted by Vegetoast

Dont you guys find that the AGM batteries take along time to charge?
I got rid of mine cause they couldnt keep up with the fridge and the starter on the car was always sluggish, Now I'm back to the standard batteries I dont have those problems anymore. One of my AGM batteries has got some good use in my ride on mower cause it sits around alot. I guess also we camp alot and use the batteries all the time.

As far as I know If you charge your agm battery or any battery at a rate more than 10% of its copaciticty continuously your cooking it. 30-40 amps constant cant be good.

Great work Deeptank, I like your box!

Nah, the Pulse Hyper gel battery charges just fine - no issues whatsoever.

There is a fundamental difference between deep-cycle and starter batteries:

Starter batteries have thin lead plates (= more surface area) and can stand large current draws (i.e. a starter motor or a winch) for a short period of time. However, they can't take a deep discharge - and by that I mean even 50% - as they can be easily killed that way. Typically, when you start a car, the starter battery is only drained by about 3% and when you're winching, the altermator will provide charge simultaneously.

Deep-cycle batteries have thick lead plates and cannot always provide massive current rushes (such as starter motors). But they do excel at relatively low current applications for a long period of time, for fridges, lights etc. They can also be discharged to as low as 20% of their capacity repeatedly with no ill effects. And depending on the model can take a very large charge current - and as you've pointed out, they usually have a very low self-discharge, so they can sit around for a long time inactive.

There are also so-called dual-purpose batteries, which are basically a half-arsed compromise between the two. In other words, not so good at either application!

I often hear guys *****ing about having killed a 'big money' started battery, when running a fridge for a day or two. Hardly surprising - it's the wrong battery for the job! That's why ideally, both types are used - each one to do the job it was designed for.

AGM just stand for Absorbed Glass Mat - a glass fibre 'mesh' between the plates to keep them from banging into each other, when the going gets tough, as touching plates inside the battery will short it and kill it. Gel batteries have their acid turned into a viscous gel to offer a similar protection, but wihout having to sacrfice acid volume to allow for the glass fibre mesh. The only drawback for gel batteries (aside from the cost) is that they can be killed by an excessive charge voltage (usually more than 14.4v), not current. However, a good quality charger makes that issue disappear.

[Split pin]

Hey Deeptank.
Thanks for the info. I did know a bit of what you have written. But that information that you have given has informed me even more in my descions on what 2nd battery I should be using and what battery I should have in my Camper.

Cheers thanks for the info