Bongo Fury

Hi Tonys,
Regarding this,
"the guy i spoke to said the bongo is designed to run with this size of battery and fitting a a larger size then originally specified by mazda would be detrimental to other engine ancillaries such as the alternator, because the alternator would always be trying to charge the battery beyond its designed capacity"

They do talk a lot of nonsense when they think they have a captive audience in my (humble) opinion.
An alternator will give as much current as it is rated at, no more is possible and it won't be upset if it sees a big battery. The winter pack for Bongos has two batteries for assured starting in North Japan and many owners over here add an extra, leisure battery for the TV, computer, shower pump etc. all charged from the existing alternator.

This line of chat is used to maintain the gap between professionals and punters and exists in most professions I think. Or is it the wellknown maxim "Bullsh1t baffles brains"

My mum's plumber, who is Corgi registered and all that, serviced her boiler a few weeks ago and said on leaving, "oh, by the way, since it is colder now I turned up the roomstat". My poor old mum was sweltering at 23C while the boiler did not stop burning gas all day. She was quite comfortable at 20C and I went over and changed it back. The plumber should have turned up the boiler thermostat if anything (he didn't).
He installed the boiler but clearly does not know how they work -its a worry.

so what is the best to go for will a 90a/h 700 cold crank do, the cost is £75 or should i look eleswhere thanks

tonys wrote:so what is the best to go for will a 90a/h 700 cold crank do, the cost is £75 or should i look eleswhere thanks

Hi again Tonys,
Sorry to witter on and not address your question.
The 90 AH 700CCA battery will be fine I think. If it the size specified by Mazda and the CCA number is the same or more, there is nothing more to it.
I just had a look at my one, changed earlier this year, it is a 95 AH 680 CCA Varta lump and it does the business.
I got it from a battery specialist where I buy batteries for my work and I trust his judgments implicitly. I think I gave him the numbers Ian gave you and it is what he offered. By the way, I have a 110 AH leisure battery under the bonnet which is charged by the same alternator! Nuff said.
Hope this helps,
Tim

fitting a larger capacity battery will make the alternator work harder. complete rubbish I am afraid.
the larger capacity 12 volt battery eg 100AH will deliver when fully charged, a 50 amp load for two hours.
A 50 AH battery will deliver a 50 amp load for only one hour.
While it is true to charge a larger capacity battery from flat to full will take more time .once its on your Bongo charged up it will make the exact same demands of your alternator.
with regards cold crank current rating ( or peak maximum current) then the bigger the better. Anything over 300 will suffice. if you having difficulty starting your Bongo above this -then its something else with your Bongo and nothing to do with your battery. My recomendation is that a diesel Bongo in a good state of health should have no starting problems in the UK with a battery greater than 80AH. Try EBay and batterymania for Value for money batteries.