Devices to charge 12V deep cycle from cars 12V output?

[Nivel Egres]

Is there a cheap charger that would allow me to charge a 33Ah deep cycle battery from my car power source while I am driving? Since its 10.5V to 15V cycle, I guess I can hook it up directly but I am worried about what happens when I start the car. There must be some charger out there, cause I've seen people charging their RC cars from lighter socket.

edit: apparently, there are devices that can do this for cheap, e.g. this one which might be worth a try: http://www.hobbyking.com/hobbyking/...ld_Car_Charger_for_DJI_Phantom_2_Battery.html

 

[Nivel Egres]

Battery is Sealed Lead Acid - i.e. one here: http://www.amazon.com/gp/product/B00KQX5FPQ
the cycle - my understanding is that car VDC output cycles from 10.5 through 15 volts so to get it perfect I'd need a multi-stage charger like this one: http://www.powerstream.com/DCC.htm which is a bit pricey

PS. I am tempted to say that once I include this feature, it is cost-efficient to go with GoalZero products

 

[DiploStrat]

You car already has an expensive battery charger, why would you want to buy a cheap one? Connect your battery to your starter battery with properly sized cables and the switch or relay of your choice. A 33Ah AGM battery is a trivial load.

 

[wirenut]

No "device" needed. Just 2 wires and a fuse. Hook the aux. battery to your main battery when the engine is running. Unhook when it's not running. You can automate that process if you want.

 

[JD914]

Not to thread jack, (ok, I am) but along these lines, could I create the world's simplest dual battery "system" while camping by simply setting a second battery (say, one that I've found laying around my warehouse) on the ground and leaving it hooked up to my starter battery via jumper cables? A solar panel would keep things topped off during the day but I'd have plenty of reserve charge for my fridge and camping lights at night....

Thoughts? I guess I'd be concerned about one of the clamps popping off a terminal, but any other worries?


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[dvas]

DJI 2 uses Lithium polymer battery and the above charger suits only that chemistry.
Connecting AUX battery to the alternator is possible and it works, as long as the AUX battery is the same chemistry (preferably the same age and size) as the main battery.
I am also looking for this kind of solution in order to answer the following need:
Main battery in car (Forester) is a standard lead one. In the back, I have deep cycle AGM 100Ah for ARB fridge. I want this battery to be charged when the car is on, while when the car is off, the fridge will work from the AUX battery.
The only solution that is not DIY is the D250S DUAL charger.

 

[DiploStrat]

DJI 2 uses Lithium polymer battery and the above charger suits only that chemistry.
Connecting AUX battery to the alternator is possible and it works, as long as the AUX battery is the same chemistry (preferably the same age and size) as the main battery.
I am also looking for this kind of solution in order to answer the following need:
Main battery in car (Forester) is a standard lead one. In the back, I have deep cycle AGM 100Ah for ARB fridge. I want this battery to be charged when the car is on, while when the car is off, the fridge will work from the AUX battery.
The only solution that is not DIY is the D250S DUAL charger.

Good catch on the DJI being appropriate for Lithium.

I would agree on needing to match chemistry, but not on your other points.

-- If your Subaru charges at the appropriate voltage, typically around 14.4v at 20C, then all you need is a properly sized connection between your starter battery and your camper battery. I would recommend some way of disconnecting the two batteries when not on charge, I like automatic relays, but you could, if you don't have solar, use an ignition controlled relay or even a manual switch.

-- The CTEK D250S is a nice product but it has very low output, hence the recommendation that it be combined with a CTEK SmartPass. This combo gets pricey, but it can be a very good deal if you have a small solar setup as the D250S incorporates a solar controller.

-- Your stater battery and camper battery do not have to be of the same size or age; just similar chemistries.

 

[toyotech]

Is there a cheap charger that would allow me to charge a 33Ah deep cycle battery from my car power source while I am driving? Since its 10.5V to 15V cycle, I guess I can hook it up directly but I am worried about what happens when I start the car. There must be some charger out there, cause I've seen people charging their RC cars from lighter socket.

edit: apparently, there are devices that can do this for cheap, e.g. this one which might be worth a try: http://www.hobbyking.com/hobbyking/...ld_Car_Charger_for_DJI_Phantom_2_Battery.html

Anyome know if the above charger work for a dji phantom 3 ?? I need for one an upcoming trip and like to bring my drone.

 

[dvas]

Good catch on the DJI being appropriate for Lithium.

I would agree on needing to match chemistry, but not on your other points.

-- If your Subaru charges at the appropriate voltage, typically around 14.4v at 20C, then all you need is a properly sized connection between your starter battery and your camper battery. I would recommend some way of disconnecting the two batteries when not on charge, I like automatic relays, but you could, if you don't have solar, use an ignition controlled relay or even a manual switch.

-- The CTEK D250S is a nice product but it has very low output, hence the recommendation that it be combined with a CTEK SmartPass. This combo gets pricey, but it can be a very good deal if you have a small solar setup as the D250S incorporates a solar controller.

-- Your stater battery and camper battery do not have to be of the same size or age; just similar chemistries.

My future setup was supposed to be the following:
ARB fridge in the car 24/7, used daily for groceries and cold drink during hot summer days in this part of the world. During the driving, I wanted the AUX battery to be charged, while the car is OFF the fridge should run from aux.
SInce last two days, I am doing a test at home: fridge set to -4C (this way at the bottom, based on temp reading inside, the temp is 0C at the bottom), after 48 hours with fridge 3/4 full, the battery dropped to 11.8V. The fridge is set to low in conf to cut off at lower possible voltage. I want to see how long it can work.
Your idea of connecting two batteries (even different chemistry) to the same car alternator sounds good, although it can only work IMHO for topping off the battery, since it is a rather stupid charging and not multiple step one.
The simplest way is to connect via relay connected to ignition, so as soon as the ignition is off, the fridge is powered from the aux only. When ignition is on, the fridge can be powered directly from the power socket of 12V (voltage level controlled) or still from the battery connected to alternator (voltage will be higher).
Are there any decent products for this setup or should I just create one?
CTEK combo (smartpass with dual charger) is VERY pricey, but I was not able to find any specs for max current charging to understand the speed. I though it can be up to 20A (too good to be true?). Furthermore, I do not plan on any solar panels to be attached.
I hope this i not considered as thread hijack.

 

[dvas]

I found two great articles on the approach to use alternator to charge the aux battery (on the fridge and solar web site), you just need the battery isolator. It is explained in detail how and what to use. They are suggesting using the Enedrive dual battery VSR isolator (Volt Sensitive Relay).
I believe this solution is going to give you the solution you are looking for.
I am also interested now in this solution, since ctek is just way to expensive.
Here, another solution is used by most users. It is a isolator from IBS (Intelligent Battery Solutions), a Swiss company. It is also an expensive product though.
In the mean time, after 57 hours, the voltage is 11.99V on the battery (I remembered wrongly in my previous post)

 

[DiploStrat]

My future setup was supposed to be the following:
ARB fridge in the car 24/7, used daily for groceries and cold drink during hot summer days in this part of the world. During the driving, I wanted the AUX battery to be charged, while the car is OFF the fridge should run from aux.
SInce last two days, I am doing a test at home: fridge set to -4C (this way at the bottom, based on temp reading inside, the temp is 0C at the bottom), after 48 hours with fridge 3/4 full, the battery dropped to 11.8V. The fridge is set to low in conf to cut off at lower possible voltage. I want to see how long it can work.
Your idea of connecting two batteries (even different chemistry) to the same car alternator sounds good, although it can only work IMHO for topping off the battery, since it is a rather stupid charging and not multiple step one.
The simplest way is to connect via relay connected to ignition, so as soon as the ignition is off, the fridge is powered from the aux only. When ignition is on, the fridge can be powered directly from the power socket of 12V (voltage level controlled) or still from the battery connected to alternator (voltage will be higher).
Are there any decent products for this setup or should I just create one?
CTEK combo (smartpass with dual charger) is VERY pricey, but I was not able to find any specs for max current charging to understand the speed. I though it can be up to 20A (too good to be true?). Furthermore, I do not plan on any solar panels to be attached.
I hope this i not considered as thread hijack.

This part of the world? Dude, I'm in Jerash!

Go look at the articles on my website - I do a lot more than top up a 600Ah battery bank and I do a lot more than keep the beer cold - I run an air conditioner, microwave, and induction cooktop.

It can be done. (Either that or I have been deluding myself for years.)

In this part of the world you REALLY need to be looking at solar.

Ma Salaama!