Arkpak Buck Boost converter questions

msand1977

Observer
I have had the the Arkpak 730 for several years now, and it has never charged correctly in the Vehicle. I think this is mostly due to Toyota smart alternators voltage fluctations. In my 5th gen 4runner it almost never charges and in my 3rd gen Tacoma I ran 10awg wire to the bed and it charges sometimes. When the Alternator voltage drops below 13.4V the Arkpak quits charging. I was looking at installing a Buck Boost Converter to stabilize the voltage at 13.8V, so that Arkpak wont go in and out of charge modes. Something like this https://www.amazon.com/gp/product/B07WFMG11F/ref=ox_sc_saved_title_1?smid=A3GYM455B71YGR&psc=1. What do you guys think?
 

john61ct

Adventurer
That type of converter can often be decently robust.

If the DCDC charger in the Arkpak never pulls over say 80-90% of the converter's rating, should be OK.

If you were charging off solar I'd point out the %losses at each step

but from an alternator NP.

What is the battery inside?
 

john61ct

Adventurer
Great AGM that.

Then the DC charger directly feeding its charge hopefully is boosting to a higher voltage within the range spec'd on their data sheet.

If you ever get the opportunity to charge it overnight direct off a like 40-60A mains charger that will help it get a longer life.
 

msand1977

Observer
I was thinking of just putting male and female fused Cigarette plug on the input and output of the Voltage converter, then it would be portable. Also are Voltage converters constant current, or are like everything else where current depends on what the load pulls for amperage?
 
Last edited:

john61ct

Adventurer
I was thinking of just putting male and female fused Cigarette plug on the input and output
Standard ciggie sockets are IMO a dangerous abortion, avoid like the plague for anything important, or that you use regularly. Never more than 5-6A and only for short periods, as in a few minutes. Even then they are risky, an inherently poor design!

Blue Sea has a nice socket design that twist-locks with the matching plug, but will also accept standard ciggie plugs for smaller (
Also the BMW/ Hella/ Merit/ Powerlet "Euro-style DIN" (ISO 4165) style is very robust.

Anderson plugs for high amps, for me my standard, for almost all power connections.

If you standardize on one of the last two types, there are adapters for guests, temporary use of devices with standard ciggie plugs.
 

john61ct

Adventurer
are Voltage converters constant current, or are like everything else where current depends on what the load pulls for amperage?
Source presents a Voltage, and "makes available" a maximum Amps current. Which may be spec'd as peak, continuous, and / or with time ranges in between.

The loads are what determine the actual current, pulled / demanded.

The source device may actually limit current to the maximum current while maintaining voltage setpoint, ideally adjustable

but that costs more, usually just designed with one of four different OCP strategies, sometimes combined and/or with a timer, with or without auto restart attempt

limiting (voltage drops)
hiccup
latching
shutdown
 

msand1977

Observer
Standard ciggie sockets are IMO a dangerous abortion, avoid like the plague for anything important, or that you use regularly. Never more than 5-6A and only for short periods, as in a few minutes. Even then they are risky, an inherently poor design!

Blue Sea has a nice socket design that twist-locks with the matching plug, but will also accept standard ciggie plugs for smaller (
Also the BMW/ Hella/ Merit/ Powerlet "Euro-style DIN" (ISO 4165) style is very robust.

Anderson plugs for high amps, for me my standard, for almost all power connections.

If you standardize on one of the last two types, there are adapters for guests, temporary use of devices with standard ciggie plugs.


Right now I have Bluesea plugs, I like the new ARB style but those are hard to find in anything but female
 

Brett From Ark

Supporting Sponsor - ARK
I have had the the Arkpak 730 for several years now, and it has never charged correctly in the Vehicle. I think this is mostly due to Toyota smart alternators voltage fluctations. In my 5th gen 4runner it almost never charges and in my 3rd gen Tacoma I ran 10awg wire to the bed and it charges sometimes. When the Alternator voltage drops below 13.4V the Arkpak quits charging. I was looking at installing a Buck Boost Converter to stabilize the voltage at 13.8V, so that Arkpak wont go in and out of charge modes. Something like this https://www.amazon.com/gp/product/B07WFMG11F/ref=ox_sc_saved_title_1?smid=A3GYM455B71YGR&psc=1. What do you guys think?

Hi MSAND1977

when charging the Ark Pak via the DC to DC car charger i have some questions they are below.

1- are your charging and discharging at the same time ?
2- are you just charging the Ark pak and have nothing plugged in taking power from it ?

i do not recommend your course of action the Ark pak DC to DC car charging is only as good as the electrical system it is plugged into.

(not blaming the jeep its a process of elimination to understand who-what, when, where and why)

i would strongly recommend you check the voltage coming out of the cig socket without anything plugged into to as long as it above 12 volts the DC to DC car charger will work and operate to spec.

a fix i strongly recommend is upgrading the electrical wire to a thicker gauge to combat voltage loss over say the 6 meters, standard sockets are either 2mm or 3mm thick cable i would strongly suggest to increase this to a minimum of 6mm or 8mm this will help reduce voltage drop over the 6 metres plug you using, i would also fuse it at 10 amps.

also just a note the DC to Dc car charging can produce up to 120 watts but this will only ever happen when the battery is at or very close to 0% which is 10.8 volts as a rule of thumbs if volts are low your amps are high as the battery is hungry for a charge up, but if your volts are already high say 12.6 volts or more the battery is not has hungry for the amps as the voltage is already high.

i look forward to your reply on the above two questions.

if you have any additional information to supply please do

look forward to being part of the solution.

Regards

Brett from Ark
 

msand1977

Observer
Hi MSAND1977

when charging the Ark Pak via the DC to DC car charger i have some questions they are below.

1- are your charging and discharging at the same time ?
2- are you just charging the Ark pak and have nothing plugged in taking power from it ?

i do not recommend your course of action the Ark pak DC to DC car charging is only as good as the electrical system it is plugged into.

(not blaming the jeep its a process of elimination to understand who-what, when, where and why)

i would strongly recommend you check the voltage coming out of the cig socket without anything plugged into to as long as it above 12 volts the DC to DC car charger will work and operate to spec.

a fix i strongly recommend is upgrading the electrical wire to a thicker gauge to combat voltage loss over say the 6 meters, standard sockets are either 2mm or 3mm thick cable i would strongly suggest to increase this to a minimum of 6mm or 8mm this will help reduce voltage drop over the 6 metres plug you using, i would also fuse it at 10 amps.

also just a note the DC to Dc car charging can produce up to 120 watts but this will only ever happen when the battery is at or very close to 0% which is 10.8 volts as a rule of thumbs if volts are low your amps are high as the battery is hungry for a charge up, but if your volts are already high say 12.6 volts or more the battery is not has hungry for the amps as the voltage is already high.

i look forward to your reply on the above two questions.

if you have any additional information to supply please do

look forward to being part of the solution.

Regards

Brett from Ark
[/QUOTE
Hi MSAND1977

when charging the Ark Pak via the DC to DC car charger i have some questions they are below.

1- are your charging and discharging at the same time ?
2- are you just charging the Ark pak and have nothing plugged in taking power from it ?

i do not recommend your course of action the Ark pak DC to DC car charging is only as good as the electrical system it is plugged into.

(not blaming the jeep its a process of elimination to understand who-what, when, where and why)

i would strongly recommend you check the voltage coming out of the cig socket without anything plugged into to as long as it above 12 volts the DC to DC car charger will work and operate to spec.

a fix i strongly recommend is upgrading the electrical wire to a thicker gauge to combat voltage loss over say the 6 meters, standard sockets are either 2mm or 3mm thick cable i would strongly suggest to increase this to a minimum of 6mm or 8mm this will help reduce voltage drop over the 6 metres plug you using, i would also fuse it at 10 amps.

also just a note the DC to Dc car charging can produce up to 120 watts but this will only ever happen when the battery is at or very close to 0% which is 10.8 volts as a rule of thumbs if volts are low your amps are high as the battery is hungry for a charge up, but if your volts are already high say 12.6 volts or more the battery is not has hungry for the amps as the voltage is already high.

i look forward to your reply on the above two questions.

if you have any additional information to supply please do

look forward to being part of the solution.

Regards

Brett from Ark

Brett, I have run 10 gauge cable from under the hood of my 3rd Gen Tacoma through a 30amp relay to the bed using a Blue sea socket. I get around 13.4v-13.6v on average at the socket. I have an Indel B 50qt fridge plugged into the Arkpak and the Arkpak plugged into Blue sea socket when I go on trips. I start out with a full Battery and a pre cooled fridge before trips. In March this setup worked flawlessly for 10 days in Baja, so I thought I had fixed the going into and out of charge mode on the Arkpak. 2 weeks ago I went to the mountains in Arizona and the charging issue returned. I even idled my truck for 4 hours with no improvement in battery %SOC, I relied on solar mostly. My battery is a Northstar group 31 Agm
 

msand1977

Observer
Just as an experiment. I have the Arkpak plugged into the AC charger and the Fridge plugged into the Arkpak. The Arkpak is still going in and out of charge mode. The fridge pulls a max of I think 4 amps and the charger is is rated at 7 amps. Am I missing something?
 

john61ct

Adventurer
Fridge load duty cycle pulls battery voltage down, charger brings it up, both active at the same time in between, whether above or below what the voltage would be if quiescent and isolated depends on a half dozen different factors.
 

msand1977

Observer
Also if I’m on strictly a 100w solar panel with with 6amp charging at best, I have zero battery issues. That’s also with the fridge running
 

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