Battery Amp Hours

Submitted: Thursday, Feb 26, 2004 at 00:14

ThreadID: 10800 Views:3170 Replies:5 FollowUps:4

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Macca1

Hi all,

I have a 2003 diesel Navara. Does someone know what amp hours the standard factory battery would be, I can't find it any where.

I'm off camping this weekend and am trying to workout how long my Waeco fridge will run on the battery. Waeco advertise the fridge will draw 3.5 amphours but only runs about 30% of the time so effectively _Affordable_Storage_Drawers.aspx about 1.2 amphours.

I also have a generator but can't stand it running all the time. I don't have dual batteries but that's next on the list. I have a Jumpstart battery pack as backup but that's only 17.5 amphours.

Any info would be great.

Macca

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Reply By: V8troopie - Thursday, Feb 26, 2004 at 01:18

Thursday, Feb 26, 2004 at 01:18

Macca,
I am curious if your jumpstart battery pack actually could start a cold diesel engine, have you tried it?

Car batteries are usually rated for their cranking capacity, rather than for how many Ah at what current, as deep cycle batteries are. Car batteries expect to be charged after starting the engine, that is perhaps why there is no deep discharge Ah rating on them.
How long your fridge is actually running also depends on the ambient temperature, how full it is and wether you just put something warm inside.
Klaus

AnswerID: 48144

Follow Up By: Macca1 - Tuesday, Mar 09, 2004 at 00:04

Tuesday, Mar 09, 2004 at 00:04

Klaus,

Well I got the flat battery I was looking for on the weekend and guess what. The jumppack, whilst fully charged worked like the flat battery on my diesel. ( your comment about being curious as to whether it would start my diesel had me second guessing from the time I read it until the time I proved it)

Fortunately I heve one of those cheap chinese generators and the battery charger got enough charge into my battery in about 1.5 hours.

The jumppack started my mate's v8 without any problems (yes, we both had flat batteries).

Oh well, it's back to the drawing board and I think I'll be looking at a deep cycle second battery to run the Waeco so that I don't drain the battery whilst freezing my fish.

Macca

FollowupID: 311395

Reply By: Big Dog - Thursday, Feb 26, 2004 at 07:19

Thursday, Feb 26, 2004 at 07:19

Macca

After talking to Waeco at the fridgeshop on thursday I think you will find that the fridges draw 3.5 amps per hour on average. At least thas what they told me so you had better factor that into your calculations,

Regards
Big Dog (rebirth of Cumbo)I hope this conforms to the rules

AnswerID: 48149

Follow Up By: Macca1 - Thursday, Feb 26, 2004 at 15:39

Thursday, Feb 26, 2004 at 15:39

Big Dog,

I got the figures from the Waeco website. The explanation is quite detailed. You can find it in their FAQS section. It's not easy to find.

Regards

Macca

FollowupID: 310107

Reply By: Rosco - Bris. - Thursday, Feb 26, 2004 at 08:19

Thursday, Feb 26, 2004 at 08:19

Macca

As a result of just fitting my aux battery after a fair swag of research, I was informed by one bloke that CCA (Cold Cranking Amps)/8 = Amp Hours.

e.g. 600 CCA ..... 600/8=75 .... 75 AH

I can't vouch for it ... but that's what I was told. As stated above most starter batteries are CCA rated, not AH.

Hope this helps

CheersFidei defensor

Rosco

AnswerID: 48153

Follow Up By: ThePublican - Thursday, Feb 26, 2004 at 15:55

Thursday, Feb 26, 2004 at 15:55

Rosco,, you got it about right,, was a post reply late 92 early 93 that gave a link to the university of hawii that gave detailed info on battery conversion tables,,have tried to find the link but it seems to have gone into the ether.

FollowupID: 310109

Follow Up By: ThePublican - Thursday, Feb 26, 2004 at 16:01

Thursday, Feb 26, 2004 at 16:01

Post 5920

FollowupID: 310110

Reply By: Brett - Thursday, Feb 26, 2004 at 08:26

Thursday, Feb 26, 2004 at 08:26

I think that amp hours are only given for deep cycle batteries.

Most cranking batteries have their cranking capacity in CCA and another wset of characters RC. RC is reserve capacity. I think these numbers indicate the ability of the battery to provide a fixed load for a period of time until the battery reaches 10.4 volts(I think)

If the battery is RC135 then it will be able to provide 20 amps for 135 minutes. Remember this will be a fully charged battery with cool electrolyte and in Lab conditions with a 20something degree ambient temperature.

I used to have a century marine pro hybrid battery in the troopy and could run the FF40 waeco as a freezer for approx 4 days with approx 30-60 minutes vehicle running each day before things started to catch up.
I think this battery had a RC of 130 and the wAECO was set to run down to 9.2 volts.

Brett

AnswerID: 48155