Leisure Battery charger question

[pionte]

I am just in the final stages of refitting my Camper, I have just bought a new 85 AH Lb wich I will wire into the van using a heavy duty intelligent split charge relay that I have also bought.

My question is this...
I have an Optimate 3 Battery optimiser that I used when I had my motorbike, these are great battery chargers that are designed to be left connected to your battery for months at a time, I am thinking about incorporating this into the van to keep both batteries topped up and healthy.
Am I correct in thinking that this will work? I have read the specs for the charger (http://www.optimate-sp.com/" onclick="window.open(this.href);return false;) and the only slight concern is the maximum suggested AH rating is 32 Ah, obviously well bellow that of the starting battery and Lb, Im not planning to be charging them from flat but just topping up so do you think this will be ok?
Also am I correct in thinking that if I connect direct to Starting Battery then the Intelligent relay will also operate allowing the charging of the LB?

I am guessing that this is a 'normal' mod that people would do? Probably not using this exact battery charger but if I can use what I already have and save some money then alls good!

Many thanks for any thoughts

Mart.

[Red Westie]

This charger is far too under powered and whilst it will work as a conditioner when layed up, you run the risk of overheating whilst on a camp and connected to the mains. Also, wired the way you are suggesting means only the starter batter will recieve charge when connected to the mains.
You will need a much bigger charger, 6amps at least but 8 - 12amps preferably to keep up with possible discharge from consumers.
Martin

[Oldiebut goodie]

This charger is far too under powered and whilst it will work as a conditioner when layed up, you run the risk of overheating whilst on a camp and connected to the mains. Also, wired the way you are suggesting means only the starter batter will recieve charge when connected to the mains.
You will need a much bigger charger, 6amps at least but 8 - 12amps preferably to keep up with possible discharge from consumers.
Martin

The intelligent relay will allow the leisure to receive charge - my solar panel is wired to the starter and when the the sun goes behind a cloud the intelligent relay can be heard to click off. Likewise if I should need charge the starter from mains it will click into action also.

[jpennington]

I have an Optimate 3 and use it to charge the van batteries, although not permanently wired in. Its rated at 0.6A charging, so it will take a long time to charge from fully discharged - like several days. Nevertheless it can be done. I did it a few months ago when the original "intelligent" relay failed on a long journey so that I was running the fridge on leisure battery for several hours (until it went flat in fact).

I also have a cheapo intelligent charger (£4-50 from Lidl) rated at 0.5 A which I keep in the van and plug into the internal mains socket occasionally.
I don't leave either charger connected for long periods (like months), but then I don't do this for my bikes either. I find a quick check with a voltmeter every couple of months and a top-up if necessary is good enough for at least 5 years of battery life.

jp

[Plasticman]

Likewise, voltmeter and a charge everyfew months or as needed if its been laid up
mike

[Red Westie]

Interesting and of course the 14 volts plus would trigger the intelligent relay:
As for the basic issue here...the charger is too weak for using whilst on camp... it simply couldnt keep up with the amount of discharge so ultimately your leisure battery would go flat leaving this little charger struggling flat out to keep the ancillary equipment running ie; interior camping lights etc.

Martin

[pionte]

Thanks for the replies and advice guys

I guessed that 0.6 amps may be a little low ! I have seen some rated at 7 amps that might do a better job, but if the camp site has 240 hook up then i would use that to run the fridge and the lights I am fitting in the van will be low consumption LED ones so the 85 AH Lb should run them for a few days if not weeks!.

I must admit that this refitting of the electrikary bits is making my head hurt

Mart

[jpennington]

A few more thoughts on the battery charger topic.
I wasn't sure whether the intelligent relay would switch properly; the Optimate runs at 13.6 volts for maintenance charging which is possibly marginal,depending on the setting of the relay sensor.
So I did a test starting on Sunday. My leisure battery was about fully charged (12.7 v) and the vehicle battery at about 75% (12.4v). The vehicle battery started charging first, as you would expect, and the relay didn't switch for about 18 hours, by which time the VB was approaching full charge. My relay switches at 13.4 v. It took another 18 hours until the Optimate finished charging and the green GOOD lamp came on.

My conclusion: the Optimate is fine for maintenance charging, but not a lot of use when you are actually camping. I think I would also charge the two batteries separately, or at least do the LB first, just to be sure.

If it helps, the standard charger fitted by Westfalia in my Joker is a beast, rated at 11 Amps. In the 24 years I've had it, I do not recall ever using the charger whilst camping, even during 10 day stays on site with the family in the early days. Actually, I rarely use an electrical hook-up; the fridge runs fine on gas and the only heavy load on the LB is the blown air heater which probably draws about 1-2 A, except on start-up when its a lot more.

One warning about high current chargers, unless you pay a lot of money, they will not have the sophisticated control system of the Optimate. Overcharging is not good for batteries. A few years ago the control electronics on my Westy charger failed. When I checked I could hear the electrolyte in the battery merrily boiling away! The battery was u/s after that, but I guess it could have been much worse.

A final thought, if you just want to top up your LB then why not just go for a drive for an hour?

jp

[CovKid]

http://www.brecklandtrading.co.uk/searc ... ords=power" onclick="window.open(this.href);return false;

Bottom product. I have their earlier one (was given to me) - heres a photo. It originally had two trailer-like sockets on, one of which I removed and just fitted a 4-gang ciggy socket. Its a massive 12v transformer and delivers 17amp so keeps up with everything on 12v and normally sits hidden beneath a seat. They sometimes come up s/h - called a 'Power Ranger Pack'. The fact it has a handle means I can use it for 12v tools and testing/using items away from the vehicle too. I don't think Breckland sell them now - they were around £300+ new. In any event I treasure this bit of kit and is why I run wholly 12v even if i had 240v hookup - makes more sense.