G'day helpful folk,

I'm having my first excursion into RV ownership and recently purchased a Mercedes Sprinter that has a Campervan/Motorhome conversion.

The second battery (housed in the living area) seems very much undersized and of some non recent vintage (bit like me actually).  I intend replacing this battery so that I can rely on it for some time.

The questions are  . . . .  what battery type should I purchase?  What size battery should I look for?  Is there any particular brand that is considered better than the rest?

When I get to purchase the new battery I'm going to have to look at charging it whilst the unit is plugged into the domestic 240 volt supply.

Therefor can the more knowledgeable amongst the members recommend a suitable charger too?

Many thanks in anticipation

Keith (trying to grow old disgracefully)

G'Day Keith,

You will probably find that the auxillary battery is charged while you are going along and also when plugged into 240V, in other words probably has an inbuilt charger like most motorhome conversions do. 

From memory my auxillary is a deep cycle and is reasonably large, it may be a previous owner or dealer has swapped the one that was in there.

A motorhome dealer or somewhere like Batteryworld should be able to help, although plenty of experienced people on here so expect a few more replies.

jimricho wrote:

---

"G'day Keith and welcome,

My guess is that the vendor just fitted any old battery to have one there when they sold the rig.

I'd suggest an AGM ("Absorbed Glass Mat") type battery of at least 100 ah ("amphours") capacity as a minimum. Regular "free campers" on the forum will probably suggest double that and I have no argument there, although 100 should be adequate if you're mostly staying in caravan parks where there's mains (240v) power available.

I'd also strongly suggest that you install a "smart" charger such as a Ctek 7 amp unit. If you opt for a larger battery you'll need a charger with appropriately more capacity, Ctek do a range of these. There are many other brands of smart chargers on the market that would also be fine for the job. "El cheapo" chargers including so-called automatic ones are not recommended for use with AGMs.

Again if you're mostly staying where power is available I wouldn't be worrying about solar panels at this stage but if your camping "modus operandi" changes you will probably want to revisit this option.

cheers,

Jim

PS: If you click on the underlined links above it will take you to more information."

---

 G'day Jim,

Thanks for your informed input it is appreciated.  It seems that the local stockist of the Ctek chargers in the Hobart area is Batteryworld.  Looks like I'll be paying them a visit before too long.  Many thanks once again.

Keith

Keith,

My Hi Ace Campervan conversion had a CTEK XS7000 Battery Charger fitted as standard, also a Redarc Smart Start SBI Duel Battery Isolator Solenoid, so just check yours to see if the Merc already has something similar fitted.

Batteryworld has been ok for me in the past, but any like business or Auto Elecricians should be ok.  I would be checking with a campervan sales or conversion place first, but just make sure a salesman knows there stuff and doesn't give you a load of crap.

I don't have any solar or anything additional on my campervan other that already mentioned and the aux battery, if I stay in one spot (no power) I can get 3 days and nights running the fridge 24/7, I haven't tried any longer than that.  Bear in mind that once you travel (move again) for any reasonable distance your battery is being recharged again as well as 240V charging at caravan parks etc.  My 80 Litre Waeco fridge switches automatically from 12V/240V when required and doesn't need to be changed over on a dial etc.  Mine is a compressor fridge and does not run on gas. 

Where in tassie are you keith, I can point you to some good help on the nw coast
ceers
blaze

ps just looked at your profile so not much help

G'day Keith and welcome,

My guess is that the vendor just fitted any old battery to have one there when they sold the rig.

I'd suggest an AGM ("Absorbed Glass Mat") type battery of at least 100 ah ("amphours") capacity as a minimum. Regular "free campers" on the forum will probably suggest double that and I have no argument there, although 100 should be adequate if you're mostly staying in caravan parks where there's mains (240v) power available.

I'd also strongly suggest that you install a "smart" charger such as a Ctek 7 amp unit. If you opt for a larger battery you'll need a charger with appropriately more capacity, Ctek do a range of these. There are many other brands of smart chargers on the market that would also be fine for the job. "El cheapo" chargers including so-called automatic ones are not recommended for use with AGMs.

Again if you're mostly staying where power is available I wouldn't be worrying about solar panels at this stage but if your camping "modus operandi" changes you will probably want to revisit this option.

cheers,

Jim

PS: If you click on the underlined links above it will take you to more information.

Many thanks Blue for you input.  It is appreciated.

Regards

Keith

Vic wrote:

---

G'Day Keith,

You will probably find that the auxillary battery is charged while you are going along and also when plugged into 240V, in other words probably has an inbuilt charger like most motorhome conversions do. 

From memory my auxillary is a deep cycle and is reasonably large, it may be a previous owner or dealer has swapped the one that was in there.

A motorhome dealer or somewhere like Batteryworld should be able to help, although plenty of experienced people on here so expect a few more replies.

 Thanks Vic for your input.  I think you may be right about the "swap" comment.  What's been your experioence in dealing with Batteryworld?

 

Regards

 

Keith

---

Thanks Jim for your informed comment.

It looks like Batteryworld being the local stockists for the Ctec product so it looks like I'll be paying them a visit before too long.

Thanks again

Keith

The second battery (housed in the living area)??????

Is this compartment vented ?? If not then it should be to disperse gases from the charging. Gas build up & a flame/spark is explosive, as well as the smell its not to good for the lungs.

All other info is good,if the motor home was built correctly there should be a 240 volt charger mounted there somewhere. also facility to charge through an isolater when driving .

Enjoy.

JC.

G'day blaze and thanks for your input.

Foolowing your comment about my profile I have added a few more comments to it so that one and all can get some further information about us.

Thanks once more

Keith

keithintassie wrote:

---

Thanks Jim for your informed comment.

It looks like Batteryworld being the local stockists for the Ctec product so it looks like I'll be paying them a visit before too long.

-----------------------

Hi Keith, I shopped around for my 120Ah AGM battery and Battery World didn't get my dollars. I got it for around $50 cheaper elsewhere.

Something else to remember. My AGM 120 weight would be AT LEAST 2 times heavier than a 6 cylinders battery.

Also my camper trailer has 120A portable solar panels only for a source of power, no vehicle, no gennie as we prefer to free camp. I have a Waeco 50 L dual zone fridge/freezer (at the same time) and have never had any real dramas so far.

 

 

---

Hi Guys, I finally "bit the bullett" and purchased a 105 amp Thumper (expensive alternative) however over the last few years I got sick of running down batteries whilst "free camping" I have a Honda 2Kva generator but that seems to upset a few camping nearby even during daylight hours.  

The Thumper from flat battery status to fully charged from the vehicles altenator is between 3 to 4 hours of driving or overnight on a "smart charger using 240 volts" the battery has "no memory" so it can be recharged in several small drives.  I can not tell you how happy I am with the Thumper as my 50 Litre Waeco maintains zero degrees for around 3 days + usage, including using lighting and TV etc in the van. I considered solar back up but it is totally unnecessary as I find that charging "on the run" is more than enough to satisfy our needs. 

I think you mean 105 amphour not amp. Not meaning to be "picky" here but the difference is significant as it helps to understand the underlying meaning of these terms.

Amps is the measure of the rate of flow of current from the battery. Think of it like water flowing through a pipe. The rate of flow in the water pipe is the litres per minute (or second or hour or whatever). The equivalent in an electrical wire is amps (just amps, not amps per anything). Also think of it being like the speed of a boat being measured in Knots, not knots per hour or anything, just knots. (a Knot is one nautical mile per hour)

If the water is being supplied from a tank, the capacity of the tank is measured in litres. Likewise the capacity of the battery is measured in Amphours. That means a battery with an amphour capacity of 105 amphours will supply a load ("load" is techiespeak for anything that draws electrical current from the battery) that draws (say) 5 amps for 21 hours (105 divided by 5). If the load is 15 amps the battery will supply that current for 7 hours (based on 105 amphours at that current).

I hope this clears up what for many is confusing and please don't take this personally as it is a bit confounding to people whose talents and skills lie in other areas.

(PS: Techies please note: I have deliberately avoided the many complications of this subject such the different capacities at different rates of discharge etc, in order to concentrate on the concept only)

jimricho wrote:

---

I think you mean 105 amphour not amp. Not meaning to be "picky" here but the difference is significant as it helps to understand the underlying meaning of these terms.

Amps is the measure of the rate of flow of current from the battery. Think of it like water flowing through a pipe. The rate of flow in the water pipe is the litres per minute (or second or hour or whatever). The equivalent in an electrical wire is amps (just amps, not amps per anything). Also think of it being like the speed of a boat being measured in Knots, not knots per hour or anything, just knots. (a Knot is one nautical mile per hour) ..... etc.

---

 One of the most informative explanations of 12v I've read. I think I can now get my head around it.

Thanks muchly

Terry

Brother uses ex Telstra batteries and swears by them, they are a bit heavy though.

 Cheers

 Dave