Battery charger

[shonky]

Hi, all.

FYI if or when one purchases a battery charger outside the conventional motorhome range it's worth seeing what charge rate it reverts to whenever power is connected. Mine does not have a permanent setting but goes back to 2 amps. Fine once you know, and we're still very happy with it.

[crockitt]

Hi All will the charger in Terrys response suit agm batteries and is it possible to use that while driving? My inverter is only 600 watts Dave

[T1 Terry]

It's actually set up for AGM batteries, it could be a little low for flooded cell but there are internal adjustments. The 600w inverter should be ok, 14.4v x 40 amps is 575w. As it is unlikely to be still producing the full 40 amps at 14.4v as it's unlikely the battery will accept that much that close to fully charged, there should be plenty of scope left to allow for inefficiencies in the charger, they are pretty good though, 5% max.

T1 Terry

[Keith Morris]

"tanks" here--- I have the 20 amp charger of the same make from bit_deals on e-Bay. It cost me $ 49.00 with free delivery.
I use the charger to keep my 2 x 100 amp/hr AGM Deep Cycle - Sprinter "house batteries" charged.

It does the job (I think) I use the charger to keep my batteries charged while I am parked at home for long periods- like 1 month at a time.
I liked the charger that much I have purchased another 2 units to keep a trickle into my other cars that do not get used a lot.

BACKGROUND:-
I previously had a 2 x Arlec 4 amp chargers which I left connected to the cars when I went to the Gold Coast to take delivery of the Sprinter, thinking that I would only be away for 1 week.
As it happened I was stuck on the Gold Coast for almost 2 months. When I finally arrived back home, I found that the Calcium battery in the Spur had EXPLODED, and the same type battery in the Shadow was dead.
My neighbour phoned me a few weeks before I left the Gold Coast to tell me that the fridges and deep freeze were not working and that there was no power in the house. I found the cause when I unlocked the garage to give the cars a run.
What a mess that was, with a few months worth of meat and frozen food turned to liquid. It cost me 2 new batteries for the cars, and a new 610 litre fridge. The deep freeze was 'recovered' after being treated to remove the smell and contamination.

[BruceS]

Ouch!!
Tanks you might have been OK if you'd left the parking lights on or even the interior light.
I have an Arlec power point timer that I can set for on & off whenever I desire for a desklamp when we leave home.
Set for on at 8:30PM (summer) & off at 11:30PM looks like someone is home.
I wonder if something like that on your cheap chargers may have been a better option?
It just goes to show that a 3 or more stage charger IS worth the money?

[shonky]

Hi, all.

After a while the Jaylec charger showed it's true colours. Looks like giving it two power sources, solar and mains, upset the charge step-down process. Worked OK on a bench, but no good on an RV. Ripped it out, and yes it's for sale, and had a Protecta 7 stage charger, with monitor, fitted. Only cost over $500. Really works a treat.
But, and there's always a but, since found an electrical on-line store, Autolec.com.au, which retails( yes I checked) the Jaylec charger for $149. Seems my electrician was making 100% and if the item sold for $145 it's cost landed would be around $100.
The it became worse - the Protecta IC 2500 unit was available for $275 - $120 less.
Wait for it - while the second charger was being installed, I spotted a $40 amp meter looked to be very good value, but was advised not to purchase it. Why not? Because installation would cost around $200. Ouch.
Moral is - be an auto-electrician. If you can't beat them join them.

[crockitt]

I want to go ahead with charging my agm battery via the 40amp charger T1 Terry suggests while I am travelling. Does this connection plan seem viable? The ute has a redarc smart start fitted connected to the van via anderson plug then to van battery one only AGM120 amp hour. So do I then connect the 40 amp charger and plug into the inverter and is that safe to use without changing anything else? I am delighted with the information and friendly advice onthis forum and look forward to getting on with this project if what I am planning seems workable Dave

[BruceS]

My alternator in the Civilian is only 40A or so & I had it tested on a bench unit when charging at full Amps for a quarter of an hour and it never got slightly warm.
My suggestion is to make VERY sure your alternator can charge at it maximum for quite some time without cooking itself or wearing out the pulleys.
Most alternators are designed to only belt in quickly for a very short time & then drop back to almost nothing.
Running a big battery charger & a lot of other items might just break the bank!
Definately don't turn on high beam, 4 big spotlights & the air conditioner (fan) as well until the Amps subside.

[T1 Terry]

Hi Dave,
Make sure the inverter is big enough and strong enough to start up with the charger under full load. We had a problem with Erich & Lesley's (Swisslulu) inverter and 40 amp charger in the V8 Cruiser, I still think it was a faulty inverter, but we ended up swapping the 40 amp charger for a CTek 25 amp unit as they have a soft start up (delayed and slow build up) and that solved the problem, yet the 40 amp unit works fine on the same size Xantrex inverter in the caravan As I said, I think it was an inverter problem, but it's all working now..... I hope.
The AGM battery will only accept max charge for a short period, then it will cause the charger to reduce the current so the voltage doesn't climb too high, so the full 40 amp oad will only last for a few mins with a 120Ah AGM battery. The lithium batteries are a bit harder on the alternator, they will drive it at full load util they are fully charged, I think that may have been part of what killed my alternator, the pulley size being wrong didn't help things either, the heat from the slipping belt through the pulley would have overheaed the stator as well.

[shonky]

Hi, all.

Has anyone experience with the RedArc Smart Start isolator? Having a chat with an RV bloke in Noosa the other day about swapping the 12v Dometic fridge for a 3in1 model and was strongly advised against it. His recommendation was for the Smart Start and also to replace the battery to fridge wiring with a more substantial cable, to minimise amp draw. Seems that's a shortcoming with ex-rental RVs.