Graupner Ultramat 14 Computer Peak Charger

[Malakite]

A while ago I sought advice on here for what a good charger would be. Most of you seemed to think the Graupner Ultramat 14 Computer Peak Charger was a good level charger. I have purchased this and use it to charge my 7.2 NiCd 3600Mah batteries.

Graupner Ultramat 14 Computer Peak Charger

The problem is I needed to purchase battery connection leads for it which I got at the same time as the charger. The touble is that they constantly lift up off the charger, even if ever-so-slightly, causing the charging connection to break and then I have to fiddle for ages just to get the connection again to charge my battery. I have to say it is a right old royal pain and wondered if anyone had this charger and the same problem, or how they overcame it? I thought the battery connection leads would fit in snuggly but they just literally have to be poked inside the lead slots on the top of the charger and constantly lift off the contact points.

Also I wondered what the highest voltage setting I should apply when charging batteries is? At the moment im charging my 7.2V at a rate that takes about 40mins to fully charge, as I dont want to cook the batteries, but I expect I could charge them a lot quicker - does anyone know?!

Many thanks and sorry to be a pain

[Malakite]

Also I wondered if I should just get a dirt cheap easy to use charger instead, or would that just fry my batteries all too quickly?

[terry.sc]

Quite a few members of my club use this charger, and they don't seem to have this problem. The charging leads you are using should have standard banana plugs on them, like this, which plug into the charger. These plugs should be a good secure fit into the sockets.

As for charging rates, generally no manufacturer recommends charging their batteries at a higher than 1C rate, which means it should take an hour to charge a battery from flat. Your batteries are NiMh, not nicads, and they should not be charged any faster than 4 amps ideally. With the old nicads you could charge them at very fast rates and they would take the abuse, but you have to be more careful with the newer cells. You are better off sticking with the charger, once you have got it sorted it will be as simple as a cheap charger but it will look after your batteries much better.

[Malakite]

Quite a few members of my club use this charger, and they don't seem to have this problem. The charging leads you are using should have standard banana plugs on them, like this, which plug into the charger. These plugs should be a good secure fit into the sockets.

As for charging rates, generally no manufacturer recommends charging their batteries at a higher than 1C rate, which means it should take an hour to charge a battery from flat. Your batteries are NiMh, not nicads, and they should not be charged any faster than 4 amps ideally. With the old nicads you could charge them at very fast rates and they would take the abuse, but you have to be more careful with the newer cells. You are better off sticking with the charger, once you have got it sorted it will be as simple as a cheap charger but it will look after your batteries much better.

Hi brilliant thanks for the advice. No I don't have those heads, have the posted me the wrong ones I wonder? Any ideas where I could purchase the ones you have posted up from? Thanks

[terry.sc]

Those leads are made up from a pair of banana plugs and a length of wire. The 4mm banana plugs are a standard size and available from any electronics supplier. Try Maplins, CPC, and there are plenty on ebay.