second battery

pam

Guest
Hi hubbie thinks a second leisure battery in van will help with lights etc when wild camping but heard different views on this. Anyone got any ideas ?
 
Go for it, you cant lose as it will double your 12 volt supply of power.
Make sure you use the same Amp Hr rated battery though, and if your current leisure battery is getting on a bit i would replace that as well. Two batteries will only charge up as high as the weaker battery will allow.
 
batteries

I agree with Biker Jeff, however only one battery is not the end of the world it just depends how you use the power it contains.

I installed a second leisure battery next to the original battery myself. Simple trip to Halfords, purchase 2 battery leads and then wired the batteries together. This simple and very cheap way can only be done without fuses etc if the batteries are going to be located next to each other, I understand.

Jon
 
In answer

Hi two batteries are better then one, i fitted 2 in my hymer last year. As stated make sure they are both the same AH and age.AND USE good cable and conections and if poss a battery box with lid.
michael
 
Whilst there is nothing wrong with the suggestions made I prefer to have our two batteries wired up independently with a change over relay to switch from the first to the second. This arrangement also works better with our solar controller. The second battery mainly provides power for the laptop

Also for us most of the electrical consumption apart from the laptop is for lighting so we have installed LED bulbs. So now with the exception of the main 16w florescent all the other lights on draw less than 18W.
 
I have fitted 2- 85amp batteries side by side and also fitted a 8oo watt inverter, installed led lights over the settee, changed most of the bulbs for leds. Fitted a 240 volt 15" flat screen tv with built in dvd player, have diesel heating, so we rarely use hook up.

John.
 
In answer

Love the pic of the trike.
there is no need of a split charger if the batteries are around the same age and must be the same AH. They will both act the same, just look at the bank of batteries on an HGV, they are all wired together with no split charger needed.
michael
 
Don't copy the wiring on an HGV though as this would give you 24volts. :eek: Bearing this in mind, :confused: it's good advice from Michael!! :D :D :cool: :D JIM!!
 
Two Leisure batteries

Hi Wild Ones:),

All this has got me thinking about adding an extra battery to my van and it sounds simple enough but.......Do I simply wire + to + and - to - (or is that tooooo simple?:eek:

Cheers

Bill
 
Last edited:
Bill, it is as easy as that + to + and - to - but use a cable of not less than 6mm2 then there should be no problems

bertie
 
usually the cables fitted to motorhomes are the thinnest they can get away with, being a sparky for over 40 years i always use the biggest cable, within reason, that i can. also it is recommended to make both cables the same length

bertie
 
In answer

Hi, yes I should of said that hgv,s are 24 volt. But its a easy job, I used a good cable from some old jump leads and you can buy the connecting bits from any motor factor.
But don,t forget but the battery in a plastic box with lid, which is bolted to the floor, in case of an RTA you don,t want a battery flying around do you.
michael
 
You can often replace two wet cell batteries (leisure style not deep cycle) with one AGM battery (they can lay on their sides or even upside down) with about 120% more useable capacity than most wet cells.

My view is to do your homework and cost out what each type of battery costs per available amp hour it will produce for you.

eg;
2 x wet cells @ 85aH, cant discharge below 80% = 34aH/20% available - cheapest purchase, short life, often need maintenance, wont recover from deep discharge

2 x deep cycle @ 85aH, cant discharge below 20% = 136aH/80% available - most expensive purchase, very long life, needs maintenance, recover from deep discharge with appropriate recharging

2 x AGM leisure @ 85aH, cant discharge below 40% = 102aH/60% available - expensive, no maintenance, recover from 50% discharge quickly using standard alternator, no maintenance.
 
Very Interesting post Roger.....
If your figures are correct there, i may look into these AGM batteries as due to lack of space a second leisure battery is not an option for me.
 
2 x deep cycle @ 85aH, cant discharge below 20% = 136aH/80% available - most expensive purchase, very long life, needs maintenance, recover from deep discharge with appropriate recharging

2 x AGM leisure @ 85aH, cant discharge below 40% = 102aH/60% available - expensive, no maintenance, recover from 50% discharge quickly using standard alternator, no maintenance.
Click to expand...

Hi Roger.

What brand batteries are you using for that comparison. My research shows 50% SOC as the sensible lower limit for flooded-cell deep cycle batteries and 30% SOC for AGM (this is on a regular basis) and for the same rated capacity, deep-cycle AGMs are a bit bigger, heavier and a lot more expensive than flooded cell (deep cycle) type.

On a cost/size/weight per usable Ah basis, the AGMs do come out equal or better if you use a 30% minimum SOC for the AGMs compared to 50% for flooded.

Apparently AGMs are charged to a higher level from a vehicle alternator than are flooded cell, so this improves the cost per usable Ah comparison.

Not having to worry about electrolyte levels and - with sensible precautions - more flexible mounting and location, make AGM the winner for me.

Those who subject their batteries to cruel and unusual punishment week after week are often better off finding the cheapest cranking batteries and throwing them out when they die.

[In the context of the original post, if you are just going to parallel the extra battery then with few exceptions the choice of the second battery is dictated by the type of battery already installed]
 
Last edited by a moderator:
errrrr.......homework and example, I should have highlighted.

I was just using those rough figures as examples, close to reality, but they change according to maker and model of battery. Some makers claim that their deep cycle batteries can be fully discharged over a thousand times without damage and recover to fully charged, others specify not less than 50%. You really have to compare each available battery that will fit into the space you have available.

Thats why I looked at available amp hours being the criteria that I would use to select batteries.

You could have an enormous wet cell 200aH but if you can only access 40aH without damage, you are financially better off having an AGM of 120aH capacity and can access 60aH.
 
You must log in or register to reply here.

Users who viewed this discussion (Total:0)

Back
Top