AekPak portable battery pack

[redscorpion999]

Apologies if this has been addressed before. I've searched the site and can't find any previous discussions....

Does anyone use, or have used, the ArkPak 12v portable battery pack, and what do they think of it. There is a Mach 1 model and now a Mach 2 version costing about $200 more.

I'm looking to run a 12v fridge/freezer and couple of LED lights for no more than 6-7 days. I know there are/will be many variables, but just after some general info/criticism re the power pack. They appear to be quite a good alternative to a vehicle mounted dual battery system. Cheers

[robcaz]

Hi redscorpion999,

If you are going to run a 120 amp hour deep cycle battery the inbuilt 240volt 6amp 7stage charger is a little small & more suited to a 70 amp hour battery. A rule of thumb for charger size & also for best battery life is to have a charger that is around 10 to 15% of the battery capacity. For a 120 amp hour battery that’s 12 to 18amp, or a 15 amp to 20 amp charger. This charge is enough to dislodge the sulphate from the cells.

A multi stage charge does not necessarily pump 20 amps into the battery, but goes through the various stages ie bulk, absorption & float to fully charge the battery depending on the level of discharge.

Working out how much power is required to run your fridge is hard to calculate as there are so many variables to consider such as the fridges set temperature, the ambient temperature, how many times the fridge is opened, the number of items at ambient temperature are placed in it etc. The fridge will cycle to maintain a set temperature, so it does not run all the time.

I did a little test with our 40 litre Engel http://www.campertrailers.org/fridge_draw.htm
Jeff Pethybridge a more detail test http://www.campertrailers.org/fridge_po ... mption.htm

Another rule of thumb for best battery life is not to discharge it below 50% capacity. This must be done when the battery is at rest for at least a couple of hours with no charge or discharge http://www.campertrailers.org/elite4.jpg

You can use Richard’s solar spreadsheet to work out how long your battery will run the fridge by not adding any solar input http://www.campertrailers.org/solar_spreadsheet.htm

Since I installed a battery monitor I now have a better understanding as to how the battery charges & discharges http://www.campertrailers.org/enerdrive_elite.htm

So is the ArcPak worth $400??? I feel the smaller charger is letting it down & more suited if you are only going to run a 70 amp hour battery.

What do you need to set up a similar battery box from parts???

Battery box to suit 120 amp hour battery $75 https://www.autoelec.com.au/ssl/public_ ... 429&cat=30

CTEK MXS15 - 15 Amp Battery Charger $215
https://www.autoelec.com.au/ssl/public_ ... 766&cat=45
or
Projecta IC1500 - 7 Stage 15A Battery Charger $176
https://www.autoelec.com.au/ssl/public_ ... 258&cat=45

With the money saved at a later stage you could add a DC to DC charger to recharge your battery while driving
CTEK D250S - Dual Battery Charger $225
https://www.autoelec.com.au/ssl/public_ ... =99&cat=45
Or
Redarc BCDC1225 $339
https://www.autoelec.com.au/ssl/public_ ... 661&cat=45
both of which also have a MPPT solar regulator built in if you wish to add a solar panel later.