[dazmond]

ive been using a halfords  smart battery charger for years but its just not charging these heavy duty numax batteries ive got now.i left it on charge for 14 HOURS last night and it still didnt show a full charge!

so what do you guys use?the batteries are 105ah(2 in tandem but i only need to put croc clips on one of them)

[CleanClear]

the batteries are 105ah(2 in tandem but i only need to put croc clips on one of them)

There's ya problem...... you don't. You need to charge BOTH of them..... or find a charger that can charge a 210 ah battery.

[P @ F]

I was told that you need a charger that is rated for 10 % of the battery capacity , so you will need 2 x 8 or 10 amp chargers or 1 that can do 20 amps if you can get them ?

[dd]

To me that shows that the batteries have been heavily discharged. C-tek chargers are very good.

It is also better to charge the battery slowly as opposed to quickly, they receive more charge this way. If I were you I would charge every night as long as you are using your heater daily.

[dazmond]

the batteries are 105ah(2 in tandem but i only need to put croc clips on one of them)

There's ya problem...... you don't. You need to charge BOTH of them..... or find a charger that can charge a 210 ah battery.

oliver said i only need to put croc clips on one of the batteries and itll charge both of them up.

i thought my halfords charger would do  but its just not charging them up.

[dazmond]

To me that shows that the batteries have been heavily discharged. C-tek chargers are very good.

It is also better to charge the battery slowly as opposed to quickly, they receive more charge this way. If I were you I would charge every night as long as you are using your heater daily.

the batteries havent been heavily discharged at all mate.(reading 12.5)before i put the halford charger on last night.the charger just isnt charging these batteries up quickly enough.on my 75ah battery( that i used to use just for my pump) itd take around 4 hours to show a full charge.

i have a smart b to b split charge relay fitted

[dazmond]

every time i look at the pics of the c tec chargers and numax chargers they dont have a plug on them to plug into your extension lead.i just need one like the halfords one that works!

[Jonny 87]

To me that shows that the batteries have been heavily discharged. C-tek chargers are very good.

It is also better to charge the battery slowly as opposed to quickly, they receive more charge this way. If I were you I would charge every night as long as you are using your heater daily.

the batteries havent been heavily discharged at all mate.(reading 12.5)before i put the halford charger on last night.the charger just isnt charging these batteries up quickly enough.on my 75ah battery( that i used to use just for my pump) itd take around 4 hours to show a full charge.

i have a smart b to b split charge relay fitted

Remember if your taking a voltage test of your batteries just after driving, then it will give a false reading. Batteries need time to “settle” to show their true voltage. You might find after a few hours the true voltage of your batteries could be around the 12 mark, if your getting a reading of 12.5 after turning off the ignition.

[Jonny 87]

Ctek mxs 7.0.

Will do the job nicely. I wouldn’t go past a ctek.

[dd]

the batteries are 105ah(2 in tandem but i only need to put croc clips on one of them)

There's ya problem...... you don't. You need to charge BOTH of them..... or find a charger that can charge a 210 ah battery.

oliver said i only need to put croc clips on one of the batteries and itll charge both of them up.

i thought my halfords charger would do  but its just not charging them up.

The reason it takes so long is they have been heavily discharged by your heater (ESPECIALLY IF THE FROST STAT KICKS IN A FEW TIMES A NIGHT). It may take 24 hours or so to fully charge them. If you charge them each night it should not take so long subsequently.

[dd]

every time i look at the pics of the c tec chargers and numax chargers they dont have a plug on them to plug into your extension lead.i just need one like the halfords one that works!

My c tek has a plug. How else could it work?

[Jonny 87]

How many hours of driving do you do a day daz?

No matter how good a b2b charger is, I’m
Sure I read somewhere that batteries can only accept about 10amps per hour while under charge.

If anyone knows accurate numbers then please correct me.

So 2 hours driving would put about 20 amps back into your batteries. I’m sure the heaters take up 20 Amps just to start up, so you could easily be depleating your batteries if not charging every night. Unless of course your engine running a lot of the day.

[CleanClear]

the batteries are 105ah(2 in tandem but i only need to put croc clips on one of them)

There's ya problem...... you don't. You need to charge BOTH of them..... or find a charger that can charge a 210 ah battery.

oliver said i only need to put croc clips on one of the batteries and itll charge both of them up.

i thought my halfords charger would do  but its just not charging them up.

Ask him what type charger you will need to do this ? Think about it...... your charger can charge a battery up overnight, but now its got to do two of them in the same time with the same output , hows that gonna happen ?

Easiest solution i can see is buy another charger and charge them seperatley.

[dazmond]

Ctek mxs 7.0.

Will do the job nicely. I wouldn’t go past a ctek.

do you get croc clips and a plug to plug into an extension lead? as all the pics i see is just a little charger and nothing else

[Jonny 87]

Ctek mxs 7.0.

Will do the job nicely. I wouldn’t go past a ctek.

do you get croc clips and a plug to plug into an extension lead? as all the pics i see is just a little charger and nothing else

Yep, you get everything you need. Corocodile clips, and even a plug to plug into your mains.   

Also you get a quick charging point. I’ll take a pic of mine and post it.

[dazmond]

How many hours of driving do you do a day daz?

No matter how good a b2b charger is, I’m
Sure I read somewhere that batteries can only accept about 10amps per hour while under charge.

If anyone knows accurate numbers then please correct me.

So 2 hours driving would put about 20 amps back into your batteries. I’m sure the heaters take up 20 Amps just to start up, so you could easily be depleating your batteries if not charging every night. Unless of course your engine running a lot of the day.

engine is running for about an hour a day jonny.the thing is the batteries are reading 12.8 on the controller in the morning and 12.5 when ive just finished my last job of the day.

these smart chargers can put 30 amps at a time into the batteries.

[dazmond]

the batteries are 105ah(2 in tandem but i only need to put croc clips on one of them)

There's ya problem...... you don't. You need to charge BOTH of them..... or find a charger that can charge a 210 ah battery.

oliver said i only need to put croc clips on one of the batteries and itll charge both of them up.

i thought my halfords charger would do  but its just not charging them up.

Ask him what type charger you will need to do this ? Think about it...... your charger can charge a battery up overnight, but now its got to do two of them in the same time with the same output , hows that gonna happen ?

Easiest solution i can see is buy another charger and charge them seperatley.

cant be arsed with that.i think ill buy  a  CTEC charger thats rated up to 300ah and stick that on one of the batteries

[dazmond]

Ctek mxs 7.0.

Will do the job nicely. I wouldn’t go past a ctek.

do you get croc clips and a plug to plug into an extension lead? as all the pics i see is just a little charger and nothing else

Yep, you get everything you need. Corocodile clips, and even a plug to plug into your mains.   

Also you get a quick charging point. I’ll take a pic of mine and post it.

cheers jonny

[Jonny 87]

How many hours of driving do you do a day daz?

No matter how good a b2b charger is, I’m
Sure I read somewhere that batteries can only accept about 10amps per hour while under charge.

If anyone knows accurate numbers then please correct me.

So 2 hours driving would put about 20 amps back into your batteries. I’m sure the heaters take up 20 Amps just to start up, so you could easily be depleating your batteries if not charging every night. Unless of course your engine running a lot of the day.

engine is running for about an hour a day jonny.the thing is the batteries are reading 12.8 on the controller in the morning and 12.5 when ive just finished my last job of the day.

these smart chargers can put 30 amps at a time into the batteries.

That’s a lot more than I thought. Even that though will be 30 Amps per hour. During the day you will be using a lot more than 30 Amps.

Here is the ctek charger......

Inside the black plastic cover is my battery, so with the ctek charger you get a male black/red connection that goes onto the battery, and then you just plug the male end of your charger into
The female port. Saves messing on with crocodile clips.

[Jonny 87]

http://www.halfords.com/workshop-tools/garage-equipment/battery-chargers-jump-starters/ctek-mxs7-0-battery-charger