Battery choice

[simonr]

Lead acid batteries fall into three rough construction categories:

Wet cell - old fashioned with screw on caps to keep the acid in the cells. Prone to leaking if inverted and exploding if not well vented.

Sealed - there is still liquid (acid) in the cells but they employ clever valving to stop it leaking out if inverted or exploding in confined spaces

AGM / Gel filled - These are sealed batteries as above, but the acid is contained either soaked in to a glass-fibre blanket or in Gel (a bit like making vodka jelly with Acid!). These have the advantage that you can puncture them and the acid will not leak out. There is a down side however, the AGM / Gel itself takes up some room so they often do not have the same capacity for a given weight / size as wet cell or sealed - and they are expensive to make!

It is only recently (last 10 years or so) that AGM / Gel batteries have been able to deliver decent currents. The best of these are Optima and Hawker. They have reasonable power density and very high cranking current (Optima are about 680A and Hawkers are up to about 1700A).

In practice, you rarely need more than about 800A - two uprated winches almost stalled will draw this kind of current.

Most wet cell and sealed can deliver these kind of currents quite easily.

There are also two sub divisions - normal and deep cycle (often called deep discharge or Leisure - same thing).

Lead acid batteries are damaged if you discharge them too far. The effect of this is cumulative so every time you do it you are killing your batteries a little. Deep cycle have a chemistry and structure which allows a greater degree of discharge before damage occurs.

As fridge noted, most deep cycle batteries are not designed for high currents and are pretty useless for winching. However, there is a new generation of sealed deep discharge batteries which can deliver the current. Being non AGM or Gel, they are much better value. The ones Tony is using fall into this category - and there are a few others on the horizon including a range with cranking currents up to 800A which more than give Optima and Hawker a run for the money - but less than half the price!

Most of the recent price rise in batteries is down to the price of Lead. I suspect Mole Valley's price reflects this more than them getting greedy.

I reckon for a decent battery capable of doing the job you need to be spending about £90 to £100 inc vat at the moment. In that price range, there are a few blistering examples!

Si

[Matt Neale]

typical as i currently need some new ones! or think i need new ones not sure they are holding charge anymore, just need to get them tested.

James,

I have a decent battery drop-tester here if you need it. Let me know what batteries you want - I may be able to assist

Matt

[smo]

So what would people suggest now Fiamms are tricky to find...exxides? optimas (personally i hate them) or somthing else?

[JST]

I reckon for a decent battery capable of doing the job you need to be spending about £90 to £100 inc vat at the moment. In that price range, there are a few blistering examples!

i reckon Si may have an answer there - maybe we could have an X Battery.....

[Superpants]

Adding to the discussion, AGM batteries tend (rash generalisation) to have a better cold crank amperage (CCA) than gel cells. I would personally avoid gel for this reason. Various manufacturers have slightly different technologies AGM(spiral wrapping as is the case with Optimas), pure lead plates etc which affect this rating.

There has been a lot of rationalisation in the battery market over the past years, so that there is very little primary battery manufacture in Europe at all. A vast amount of batteries are now coming from China (However nonsensical shipping scrap lead to china for them to make batteries and ship back may be...). Prices have rocketed as Si has said due to the lead prices, but also as the Chinese started adding export taxes to the batteries recently, when they hadn't before.

Enersys now own Hawker as well as Fiamm, Varta and Oddessy and I understand the Varley red tops favoured by the racing fraternity are Oddessys in a different colour case. Personally I would use the oddessy range if money wasn't an issue, however there is a Chinese range of batteries that are pretty robust, reliable, with reasonable specs and are sensibly priced. They are badged either as Squadron, Haze or Full River if you can find a supplier of the size you need!

[simonr]

I needed to buy some batteries for my self, but didn't want to cough up £200 each for Optimas (which originally cost me £100) so I did a bit of research - rang 25 of my customers who use batteries for winching, marine, heavy plant that kind of thing asking what sort they use.

Although a few use Optima and Hawker (Oddessy), 8 out of the 25 mentioned a single make and model of battery, I personally had barely heard of. It's common in marine circles for winching & running bow thrusters and seems to have a very good rep. 800A cranking, sealed, dual terminal posts & studs and deep discharge. However, it doesn't cost anywhere near as much as its main competitors. The manufacturer is not Chinese nor is it part of Enersys either!

I need to be a bit coy about the identity as I don't want anyone else sticking their nose in - if you catch my drift - before we can do a proper deal.

We will have a load of them for Billing with a bit of luck though.

Si

[Jon White]

I'm just running a pair of 072's which came from the local motor factors with a decent guarantee period. I think the pair (trade) cost me about £70. Had them for a couple of years now with no problems whatsoever.

Cheers

Jon