Batteries and dynamos

[MiketheBike]

I am sure this has been covered before, but my search has found nothing.

 

I think the time has come to replace the batteries in the Ferret.

I know they are 12v/60A affairs, do I have to replace them with 60A ones, or can I replace them with smaller ones...the question being are the batteries matched to the dynamo output?

I don't want to fry new batteries, but would also like to get two smaller ones that will maybe fit in the right hand battery box, so I don't need to take the air filter out to charge them (lazy git).

 

Mick

[john fox]

but would also like to get two smaller ones that will maybe fit in the right hand battery box, so I don't need to take the air filter out to charge them (lazy git).

Mick

 

Mick

 

that is a common modification done by many owners.

Not by me personally however, I prefer big batteries to make starting easier

you don't really need big ones :n00b: as you are not on radio watch anymore

[AlienFTM]

... which is a good job cos after the batteries have gone flat whilst running an automatic rebroadcast net, starting a Ferret on the handle is not a fun job.

[paul connor]

Cant see it being that bad? b60 is easy to start on a handle?

[MiketheBike]

John,

 

so I can safely place two smaller capacity batteries in their place?

I think the dynamo bungs out 25A, which is pretty low by todays standards? So if the new batteries can take a 25A charge, they should be OK, or am I going down the completely wrong track?

 

Mick

[sirhc]

Mick,

 

If the batteries are charged they will stop charging, whatever the capacity, so you shouldn't have a problem.

 

Chris

[MiketheBike]

Thanks Chris....just need to see what I can get, bearing in mind the draw from the starter etc.

 

Cheers

 

Mick

[AlienFTM]

Cant see it being that bad? b60 is easy to start on a handle?

 

By the late 70s / early 80s, Ferret had been around for about ... well ... ever. Any particular example had had scores of drivers. They didn't by any means spend their entire lives in combat. If it failed to start, it would invariably be easier to slave start it from the other car in the section than to crank it. The crank handle was an item which lurked in the bottom of the bin. (There isn't a mount for it on the glacis plate is there? It's the age you know. Memory is the first thing to go. Well, I cannot remember anything that went before memory.)

 

I have crank-started the odd Ferret, and turning over the B60 isn't so difficult (but make sure you position yourself correctly so that when (if) it catches, the handle doesn't bit back and smack your kneecaps. But there is the matter of removing the access plug which has been painted over almost as many times as the car has been handed over. Not easy if the "wrong" end of the crank (used to remove the plug IIRC) has been stripped and, having been forced into the many layers of paint filling the hole in the plug.

 

And so it goes on. And of course you know it is going to fail to start when it and you are cold and wet.

 

ISTR last time I struggled to start a Ferret (short circuit in the braking system left the brakes lights on permanently) was on Ex Spearpoint 80. We were lucky that, being umpires and non-tactical, we had parked in the open, on a slope and I was able to push it enough to start rolling down the hill and my driver got one shot at turning it over, which he did.

[fv1609]

b60 is easy to start on a handle?

 

Yup. (Forum says "yup" is too short a message to send, but having said this it should be ok now!)

 

PS Ah yes Paul do you have recent experience of this perhaps?

[Val]

You should be safe in replacing with any type of battery, I replaced the 60amp ones in the Saracen with deep cycle 125ah ones. 25amps might seem like a lot, but it really isn't. Any power you consume during driving is going straight from the generator and backed up by the batteries rather than the other way around if that makes sense? Before I replaced my batteries, I had a pair of wheelchair batteries in there 20ah each! They did the job but bless them they could only manage a few cranks before needing a charge up. Very low CCA.