Is the charger any good for mk gel batteries?

[ICEUK]

Charger must be plug in and forget, able to charge at 12amps. User input is not possible due paralysed from neck down.

https://www.ebay.co.uk/itm/195758395192 ... =WHATS_APP

[daveonwheels]

no

[ICEUK]

Any suggestions? It must be plug in and that's it.

[Burgerman]

Almost all chargers claim to charge AGM and Gel. They seem to think its all the same thing...
But its not.
Well they WILL charge gel, but they will have a short lifespan.

Because anything that is intended for wet/agm/general lead acid will charge at 14.4 to 14.7V approx. And that will give you half the lifespan. And worse, they never tell us at what point the charger stops charging.
It should do that after 8 hours, or 1000th of the battery Ah in mA. So a 70Ah battery would be 70 to 140mA termination of CV voltage. THEN drop to a lower 13.5V (per battery, so double this)

But theres never any info. And they normally stop charging way too soon after say 4 to 5 hours. So on top of the over voltage we gat undercharging. Which again shortens lifespan by allowing sulfation to build fast. Instead of returning the sulfates back to the electrolyte.

So this is why its probably a bad idea.

And this comment in the feedback reinorces this:

Nicely Finished Charger

Very Nicely Made unit.
I would expect it to last
Good clear LCD Display.
Powerful Charges quickly and settles down to float mode quickly.

Well it SHOULDNT!

[ICEUK]

I agree it's not ideal but is it better than a standard mobility charge that never gets the full 12-16 hours to charge the battery?

[Burgerman]

What voltage, when it transitions, are all at least as important as the 8, 10 or 12A part.
The advantage of 12A is that it gets the bulk of the charge done faster, and that allows a longr time in order to get the long CV stage in during the limited time we have overnight.

If we charge at 12A initially, and then the charge current naturally falls away and the charge gets slower and slower that we get more charge done in the limited time we have available. So the battery lasts longer.

After 4 hours its about 90% charged. After 6 hours its around 99% charged. The last 1% is important. It is the part that returns the last of the sulfates back to the acid. Or you lose some capacity every charge. But that 1% may take another 3 or 4 hours. So 1.5 to 2 hours at 12A or so dependin on how much you are returning. The rest is then a long tail off of ever diminishing current. While voltage is held at a steady 14.2 or 28.2V for gel.

It only takes 16 hours to charge when the charger stops too soon, and you then have to rely on FLOAT to do the rest. And that takes forever. Even longer if you start at 8A.

Like this...
6 hours at 12A charge and the current is down to a still too high level. 3 and a half hours later and it was done! When it fell to 100mA and 8 hours CV an 9.5h total.

[Burgerman]

Now its true that any old charger will charge batteries. To a greater or lesser degree. But if you want the to last, then thats a different story.

The only chargers I saw that were capable were al what you dont want.
The Victrons, user programable.
The ZXD from shirley, user programable.
The PL8s we use for lithium I also use for lead. Again user programable.

Plug and play? Dont know of any. There may be some. But even those selling them do not usualy have a clue what they are selling or why it matters. And never post the actual charging specs. When they do they are inevitably wrong.

I wish there was an easy answer but there isnt.
Its actually easier to get cheap nasty AGM batteries as they are both less particular, and more chargers get this right at least voltage wise. But most of the AGM batteries are junk. Or eye wateringly expensive (think Odyssey etc).

[LROBBINS]

For lead batteries, the ZXD once it's been programmed to do so, can be plug and play - 3 stage charge probably using chair-type connector rather than SB50, auto turn on when plugged in, auto off when amps very low - and the next generation will also have a timer.

[Burgerman]

And also some dual bank marine chargers have a gel setting that is pretty good.

For the money I would get a ZXD and configure it correctly. But they are not intuitive. The victron chargers are fairly configurable and then plug and play but the iniial config must be totally user profile and set up right. Which they go out of their way to hide in the menus.

[ICEUK]

Bm, which one of the victron chargers are you referring too?

[Burgerman]

I dont have one. Others on here do. Theres one of their blue smart chargers that is PC programable (or a phone if thats your thing) that has 24V and 12A output.

Its going to need some complicated custom settings and a one off user profile ONCE. And it will need a XLR quality connector fitting in order to be plug and play. That wouldnt bother me as I have fitted hundreds of such things in the hobby world all my life but it might stop you? Dont use any of its preset modes inc the gel one!


https://www.victronenergy.com/chargers/ ... 22-charger
Various models.
You want the one with ONE output, 24V nominal, and 8, 12, 16A outputs. You need 12. Thats the IP22 24|12 for a 12A output I think.

Heres the windows version of the programming tool. https://updates.victronenergy.com/feeds ... taller.exe
The highest you can use on the XLR connector is 12A.
I would fit an anderson and charge at 16A. And even if only charging at 12A an anderson connector with thicker cables is still better.

[ICEUK]

Thx BM, soldering/crimping don't bother me. I'll check out those links.

Thank you

[Burgerman]

https://www.amazon.co.uk/Victron-Energy ... B082X93M2J
Amazon?

The BLUE Smart Charger, IP22 24|12 (1) is what you need.

That means 24V, 12A, (1) is 1 output.

[Burgerman]

When you create a custom user setting, or when you EDIT their existing lead/gel setting, you want to disable auto everything. And set it all manually.

Ask if you need to.