Battery Charger

Has anybody had any dealings with the "volta" battery charger fitted to a Topaz. There are two charging options available which are "float" and " 3 stage". I am led to believe that Auto sleeper leave this unit set to "float" mode which is not as beneficial for the battery as it does not control the charge as efficiently as the 3 stage option. There does not seem to be much information on the internet about this unit, I would be grateful if anyone has had experience of this unit.

Thanks

John Little

I don't have any direct experience of that charger, but as a general observation, multi-stage charging is designed to make recharging from a depleted state quicker, and float charging is for when the battery is sitting unused.

So, when in storage or not being used, I'd select "float", and if recharging after taking load while away from EHU, use "3-stage".

You should normally use the Float charge. In this mode the battery is used like a reservoir that supplies the load but is being continually topped up. The batteries charge level is maintained around the full level. Even if the battery has been discharged by use off hook up for a couple of days, the charger in float mode will replenish the charge over two or three days.

If you have heavily discharged the battery by a few days use off hook up (or heavy use for a few hours), you can replenish the charge in 6 to 8 hours using the 3 stage fast charge.

If you leave the charger in the 3 stage mode for a few days the battery water level will be reduced by 'gassing' and if you continue for a month or so, the battery will be irreparably damaged

Peter

Hi

Peter Brown wrote:If you leave the charger in the 3 stage mode for a few days the battery water level will be reduced by 'gassing' and if you continue for a month or so, the battery will be irreparably damaged

I’ve never seen the “Volta unit but I’d say it was a diabolical design if it did that. The thing is the third (or last) stage should be maintenance (or float). The stage before should be controlled overcharge. That is to say taking the terminal voltage high for a short time to fully charge the battery and encourage any lead sulphate to re-combine.

It’s a bit worrying that the unit in question has a switch. Normally an intelligent charger would sense the battery state and automatically put itself into the correct mode to maximise the battery life. Perhaps I’m missing something.

If you are interested in the technical stuff have a look at the datasheet for this chip:
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What each stage is called may vary because some circuits have more “stages” than others but the last stage should always be “maintenance.”

Brod.

Hi Brod

I can't argue with the principle but in practice I know many people who've left an 'intelligent' charger switched on during a winter layoff and then found the battery plates damaged due to lack of water.

It's better to be safe than sorry.

Peter

Peter Brown wrote:I know many people who've left an 'intelligent' charger switched on during a winter layoff and then found the battery plates damaged due to lack of water.

Agreed that some of the older "intelligent" chargers were not that bright. I had (actually still have) one by Draper and it was terrible. I recall passing the car in the garage and wondering about the faint hissing - only to discover that the supposedly "smart" charger was gassing the battery furiously, even though it had not been used for weeks.

However, the latest ones - particularly the ones from CTEK - are much better. The one I have in use at the moment has (IIRC) no less than 9 stages, the last of which is "maintenance".

I have a 2007 Topaz and it does not have a Volta charger! Neither does it have float or three stage.
When I queried with A-S why the instructions in their manual re charging did not correspond with what the charger manufacturer's website said, I was met with pure waffle, so gave up and got the multimeter out.