[p1w1]

This may seem like a daft question..but looking to get a numax battery charger (connect and forget type one). There seems to be a few different ones in regards to amperage ie 12 10a, 12v 20a, 12v 30a and so on.
What exactly does that mean? does the higher the amperage mean it will charge the battery quicker or that it will just cope with a larger size battery ?

[windowswashed]

The higher the amps, the quicker it will charge.  Batteries are best charged with a smaller amperage over a longer charge than rapid charging using higher amperage in the long run maintenance to prolong the life of batteries.

[windowswashed]

Just a suggestion, use a battery to battery charger if your van has a euro 5 or 6 engine which charges better with battery to battery charger than a split relay charger

[p1w1]

Thanks windowswashed, i was thinking of going for the 20a version. I have a euro 6 engine but not the smart alternator (doblo tecnico)  and already use a split charge just want something for a quick top up really, my old halfords charger seems to take forever.

[windowswashed]

10amp would be slower but kinder to the battery.  10 amp is plenty.

I have a solar dual MPPT 20amp battery charger I intend to fit next spring to two aux batteries in my van from solar panel on van roof rack and I only went for 20amps as I have 250 watt solar panel so 10amps would be too small above 150/160 watts

[Spruce]

Thanks windowswashed, i was thinking of going for the 20a version.

The higher amperage will be for bigger battery banks.

A 10amp Numax is suitable to a battery size of 165amph if memory serves me.  If you say had 2 x 110 amph leisure batteries then they would recommend a 20 amp. (But remember that they will be advising on recharging a battery bank that could have virtually drained a 220amph battery bank over a long weekend of wild camping.)

Your charger can only charge the battery at a rate the battery will accept. So after a days work, plugging in a 10 amp Numax charger will only show a charge of 5 or 6 amps going into the battery.  As the battery gets more fully charged then the amps will drop off even lower. A 20 amp charger will still be OK but it won't charge a single battery any quicker. (After all I have a 90amp alternator on my van and that will still only charge that 110 amph battery at 5 or 6 amps.)

If you had 2 x 110 amp leisure batteries linked together, a 10 amp charger will still deal with charging that size bank if you plugged the charger every second night for example.

[dazmond]

Thanks windowswashed, i was thinking of going for the 20a version. I have a euro 6 engine but not the smart alternator (doblo tecnico)  and already use a split charge just want something for a quick top up really, my old halfords charger seems to take forever.

I have a 20amp numax "connect and forget"charger for my 2 x 105ah numax batteries and plug it in every night plus i have a smart battery to battery split charge relay for topping up when driving around....oliver at grippatank advised me to get the 20amp charger for my batteries,,,,

[Spruce]

Thanks windowswashed, i was thinking of going for the 20a version. I have a euro 6 engine but not the smart alternator (doblo tecnico)  and already use a split charge just want something for a quick top up really, my old halfords charger seems to take forever.

My late brother in law had one of those chargers that had a maximum output of 2 amps. It was a waste of time recharging the leisure batteries in his motorhome.

[Spruce]

Thanks windowswashed, i was thinking of going for the 20a version. I have a euro 6 engine but not the smart alternator (doblo tecnico)  and already use a split charge just want something for a quick top up really, my old halfords charger seems to take forever.

I have a 20amp numax "connect and forget"charger for my 2 x 105ah numax batteries and plug it in every night plus i have a smart battery to battery split charge relay for topping up when driving around....oliver at grippatank advised me to get the 20amp charger for my batteries,,,,

That's the correct advise to give as it will cover all scenarios.  It will be the right size charger if the windie in time only got the charger out when his battery bank was flat. For battery longevity we should only be discharging to 50% capacity before recharging. So if you stuck with that, then you only have 105 amps of useable power. A 10 amp battery charger would then work for you.

.

[Plankton]

I don't know if this is any use to you but I had looked at getting one for when I get new battery and it's down on price just now.
https://www.amazon.co.uk/CTEK-MXS-5-0-Reconditions-Motorcycle/dp/B00FC42HAA/ref=sr_1_3?ie=UTF8&qid=1542665416&sr=8-3&keywords=12v+battery+charger+ctek

[p1w1]

Thanks all..

[Spruce]

I don't know if this is any use to you but I had looked at getting one for when I get new battery and it's down on price just now.
https://www.amazon.co.uk/CTEK-MXS-5-0-Reconditions-Motorcycle/dp/B00FC42HAA/ref=sr_1_3?ie=UTF8&qid=1542665416&sr=8-3&keywords=12v+battery+charger+ctek

Its a 5 amp charger so theoretically half the output of a 10amp. If you topped up the battery every second night in summer or every night in winter then it will work, but it will take longer than a 10 amp if the battery/batteries could take more than a 5 amp charge.

There are a few windies that swear by CTEK chargers. I think the 10 amp one is a better choice but they are very expensive IMHO.

On a positive note I like the fact that it can be screwed into place inside the van as a permanent feature. A numax charger does not have that option. However, I use it to charge other leisure batteries and I've used it on the car as well so I wouldn't have that flexability if it was fitted to the van.