Alternative trickle charger for the starter battery

[WildBunch]

Has anybody got thoughts on the "Ablemail Electronics AMT12-2 Battery Maintainer instead of the normal Van Bits BM. It seems to pulse charge the start battery 3 sec on 15 sec off, is this good ?
I am reading the installation instructions & can't see where SW 1 & SW 2 are. "Is it me
?"https://www.ablemail.co.uk/sites/de...le Charge Installation Instructions Rev.A.pdf

 

[autorouter]

No, it's not you, these instructions are really bad. I don't actually have an AMT12-2, but I'm guessing that SW1 is not a switch but an input connection, where you feed in a +12V signal to flip it into programming mode, then use that SW1 connection in some way to program the settings profile. That's only a guess, could be completely wrong. And no sign of SW2 anywhere I can see.

 

[Jimbohorlicks]

Any info on price?

 

[WildBunch]

RoadPro do it at £68.98

 

[AgeingAndrew]

RoadPro do it at £68.98

The Ablemail AMT12 is £64.95 at www.wildebus.com and this includes cables to fit. I contacted Ablemail about this product recently and seem to remember that the photo on their website is of an older version.
The AMT12 seems to be the only battery maintainer that works properly with lithium & lead acid.

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[Lenny HB]

I spoke to an Ex Funster a few days ago who fitted a ATM12 a couple of months ago because a Batterymaster wouldn't work with his Lithium in Scotland in mid-winter. He said the ATM12 is working fine.

 

[WildBunch]

Hi
Do you know which version he used ATM12 or ATM12-2 the Wildebus web site is not clear which you may get .

 

[Hoovie]

Thought I would add some comments to this thread ref the AMT12....

The current AMT12 is the AMT12-2. Photos below:

The key difference between the AMT12-2 and the original one is the style of connections. The original ones uses 6mm studs; the new one swaps those to Feston (spade) connectors.

The instructions do need some "Plain English" re-writing, I would agree. On the plus side, the instructions ARE correct when followed and these devices really are "fit and forget" once setup.

Now Switch 1 and Switch 2 ... These are not switches as such but connections. You CAN connect switches to them to expand the devices usability however.
Switch 1/SW1: (next to Green Plug) This is a connection that allows to to select which one of the 8 preset programmes you want to use, following the (hard to follow) instructions in the Instruction Sheet. You chose the Programme depending on the type of Leisure Battery and Type of Alternator you have:
Setting 1: Standard Alternator and Lead Leisure Battery
Setting 2: Standard Alternator and Lithium Leisure Battery
Setting 3: Smart Alternator and Lithium Leisure Battery
Setting 4: Smart Alternator and Lead Leisure Battery
The setting you choose determines the Leisure Battery voltage at which the unit will turn on and the target charge voltage of the Starter Battery
There are also on the later units an additional 4 Settings (5-8) that replicate the voltage parameters of the first 4 but has a longer active cycle to deal with a greater parasitic drain on the Starter Battery.
SW1 is only ever used for initial setup of the AMT12. The only time you would typically use it to reprogramme is if say you fitted the AMT and then updated your Leisure Battery from Lead to Lithium (so change settings from 1 to 2, or 4 to 3 for example).
Talking about Programming, the 4 pin Green Plug can be used to reprogramme beyond the factory presets. It is possible to buy a USB lead to connect to your Windows PC and run the Ablemail s/w to programme it. Or on the later versions, a Bluetooth Module (ABB07) can be fitted to the plug and a Smartphone App used to reprogramme. You can use the Windows Programme or the Windows App to Monitor as well as programme, which could be of use, but generally is not needed by most folk.

The other connection - Switch 2/SW2: (next to 0V) - is something that can be of use post-installation. If a +12V signal is applied to SW2, the AMT12 is forced on and the preset programme is ignored whilst SW2 is high. It still has an on/off cycle, but is predominantly on, and does not rely on a certain voltage to be enabled.
This can be useful if you are in a situation where charging is poor (maybe over-winter in storage?) and you are ok to use some of the spare capacity of the Lesiure Battery to trickle the Starter to avoid it getting to a very low level?
I have the SW2 on my AMT12 connected to +12V via a rocker switch so I can easily flick the switch and force it on if I feel the starter is getting low and I want to give it a boost.
This graph may help illustrate that:
I was not getting any decent charging via solar this month and the starter was on the usual gradual decline.... on the 6th March, I flicked the switch to force the AMT12 on and you can see the effect on the voltage. I turned the switch off the next day and you see the voltage starting to drop again as expected. On the 12th March I plugged in EHU and the AMT kicks on when the Activation Voltage is attained, but this time the programme parameters are used and the Starter Voltage settles at around the ~12.8V

Some other points on the AMT programmes .... As mentioned there are 8 selectable presets to choose from, plus an override option via SW2.
But when running in any of the Preset Settings, there is in addition a built-in "emergency" mode that if the Starter Battery drops to a critical level, the AMT will turn on to try and save it using power from the Leisure Battery (on the basis of better to use available capacity on the Leisure Battery rather than sacrificing the Starter). However, this will only continue until the Leisure Battery drops to a certain point itself (again on the basis that you don't want to sacrifice the more expensive Leisure Battery to save the more basic Starter Battery).

I hope this helps explain the AMT12 a little better?

 

[Lenny HB]

Looking at the settings of the AMT12 the leisure battery threshold on the Lithium setting appears too high to me, Greater than 14.2v, I would have thought the lead battery setting of Greater than 13v more suitable.

 

[Hoovie]

Looking at the settings of the AMT12 the leisure battery threshold on the Lithium setting appears too high to me, Greater than 14.2v, I would have thought the lead battery setting of Greater than 13v more suitable.

You are quite correct with your observation. The Thresholds in that datasheet are out of date and got changed quite early on, in fact, and possibly even before it went on general release (which is why I didn't refer to them )
When you get an AMT12, you do also get an printed up to date datasheet showing the correct values. These are:

The Lead Activate Voltage is 13.0V: You wouldn't want to use these with Lithium however, as if you did the AMT would be active regardless of charge state until the Lithium was at a pretty low SOC, and the idea of a Battery Maintainer is for it to be active when there is a charge occuring.
If you did like that style of operation, you could set the option to Lead even with a Lithium Battery of course, but it would not really be recommended generally.

The Lithium Activate Voltage is 13.5V: Chosen as it is above the resting voltage, but below a chargers float or storage voltage, which ensures the AMT will still carry on its trickle charge function when the charger (Mains or Solar) has reverted to Float after completing the main charger, which wouldn't happen if the threshold activate voltage was at 14.2V, as you have picked up on.

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[Margaritaman]

You are quite correct with your observation. The Thresholds in that datasheet are out of date and got changed quite early on, in fact, and possibly even before it went on general release (which is why I didn't refer to them )
When you get an AMT12, you do also get an printed up to date datasheet showing the correct values. These are:

The Lead Activate Voltage is 13.0V: You wouldn't want to use these with Lithium however, as if you did the AMT would be active regardless of charge state until the Lithium was at a pretty low SOC, and the idea of a Battery Maintainer is for it to be active when there is a charge occuring.
If you did like that style of operation, you could set the option to Lead even with a Lithium Battery of course, but it would not really be recommended generally.

The Lithium Activate Voltage is 13.5V: Chosen as it is above the resting voltage, but below a chargers float or storage voltage, which ensures the AMT will still carry on its trickle charge function when the charger (Mains or Solar) has reverted to Float after completing the main charger, which wouldn't happen if the threshold activate voltage was at 14.2V, as you have picked up on.

Are there SW1 settings suitable for AGM leisure battery and AGM Vehicle battery (Fiat Ducato 2022 model year with Eco Pack stop start smart alternator) Hoovie ?

 

[Wabs]

I’m outside howling at the moon,,coz I haven’t got a clue about this stuff

 

[Hoovie]

Are there SW1 settings suitable for AGM leisure battery and AGM Vehicle battery (Fiat Ducato 2022 model year with Eco Pack stop start smart alternator) Hoovie ?

That is the Smart Alternator setting. The logic behind the lower voltage for the Smart Alternator is that room is left available to deal with the dump load of regenerative brake charging. So for your specific setup, you would go for setting #4

 

[Margaritaman]

That is the Smart Alternator setting. The logic behind the lower voltage for the Smart Alternator is that room is left available to deal with the dump load of regenerative brake charging. So for your specific setup, you would go for setting #4

Many Thanks Hoovie , that’s really helpful

 

[Lenny HB]

The Lead Activate Voltage is 13.0V: You wouldn't want to use these with Lithium however, as if you did the AMT would be active regardless of charge state until the Lithium was at a pretty low SOC, and the idea of a Battery Maintainer is for it to be active when there is a charge occuring.
If you did like that style of operation, you could set the option to Lead even with a Lithium Battery of course, but it would not really be recommended generally.

I would have thought 13.2v a better compromise, am I right in thinking if you hook it up to a PC you can tweak these settings?

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[Hoovie]

I would have thought 13.2v a better compromise, am I right in thinking if you hook it up to a PC you can tweak these settings?

You would need the official Ablemail cable to connect to a PC, and they are not cheap (they are really only supplied to distributors), but yes, you can tweak just about any settings. The better way for someone who likes to play around with settings and try different parameters (and nothing wrong with that ) is to use the Bluetooth ABB07 module. The interface is a lot simpler to use and the ABB is cheaper than the data cable as well.
(However, the PC Programme can do a lot of datalogging which can be saved to a CSV for analysis, which is good for troubleshooting for distributors or someone with a very specific and precise requirement.)

13.2V instead of 13.0V for Lead? TBH I don't think it would really make a difference? Are there Lead Batteries that settle above 13.0V?
but if you had a setup where 13.0V was too low and 13.2V was right, the beauty of the AMT12 is because it is fully programmable.
It can be tweaked to just about anything (there are some step limitations within the circuitry/electronics so if you set 13.2V, it might actually change it to 13.18V or 13.21V for example).

Back to programming .... The AMT12 uses the same 4-pin programming connection as the AMC B2B, the AMC B2B/MPPT and other devices In the Ablemail range, so you could use the same cable (or ABB07) to tweak the AMT, reprogramme your B2B and maybe reconfigure your programmable power relay, say.
When someone asks for one of these, I ask them what they have (alternator type and battery type) and programme to that string using the process in the datasheet before sending them out, but I have reprogrammed a couple via the prog port when the person had a very specific requirement. I tend to use the Bluetooth module and smartphone App to do this as it is nice and quick to do.

Considering the flexibility of this device over something like the Battery Master (more expensive, but one single way of working and only with Lead) or the Votronic (cheaper but incredibly expensive for a diode and resistor in a plastic box), it is amazing value I think.
(And for those who look for this feature ... The AMT is designed and built in the UK (Salford, Manchester to be precise))

 

[Lenny HB]

13.2V instead of 13.0V for Lead? TBH I don't think it would really make a difference? Are there Lead Batteries that settle above 13.0V?
but if you had a setup where 13.0V was too low and 13.2V was right, the beauty of the AMT12 is because it is fully programmable.
It can be tweaked to just about anything (there are some step limitations within the circuitry/electronics so if you set 13.2V, it might actually change it to 13.18V or 13.21V for example).

No, I was thinking Lithium, more from an interest point of view as if I go for Lithium, getting tempted to build one with the cell prices coming down. But I would probably stick with Votroinc solar regulator as I want the AES output for the fridge & it has a dual output for starter battery charging.

 

[autorouter]

I’m outside howling at the moon,,coz I haven’t got a clue about this stuff

If you had mains hookup, one way to keep both batteries charged is to have a big charger for the leisure batteries, and a separate small 'trickle' charger to keep the starter battery topped up. That would all work fine.

Then someone had the idea that maybe use a tricky gadget to detect when the leisure battery is being charged, and feed a small trickle charge to the starter battery whenever that happens. So no need for the second mains trickle charger for the starter battery.

Another advantage of the gadget is that when the leisure batteries are being charged by solar, the gadget still works to trickle charge the starter battery.

This thread is about how the gadget detects whether the leisure battery is being charged. A lead-acid battery has a maximum resting voltage of about 12.8V. So if it's 13.0V or more, the gadget can conclude it's being charged, and start trickle charging the starter battery.

Trouble is, Lithium batteries are different, and have a different resting voltage and a different response when being charged. So a different setting is needed for lithium batteries.

Then there's the smart alternator problem. The alternator intentionally doesn't fill the starter battery, to leave spare capacity for dumping energy from the regenerative braking system. So the gadget needs to know if it's a smart alternator, so it doesn't fill the starter battery completely. That's why the gadget needs smart alternator settings.

And finally, what if the MH is stored in a barn (no hookup, no solar), the leisure battery is at 90% but the starter battery is getting flat because it's running the alarm, tracker etc. Maybe there should be a switch to manually turn on the trickle charger even if the leisure battery isn't being charged.

And it all sounded so simple to start with... and it's still 2 days to the full moon

 

[Lenny HB]

If you had mains hookup, one way to keep both batteries charged is to have a big charger for the leisure batteries, and a separate small 'trickle' charger to keep the starter battery topped up. That would all work fine.

Then someone had the idea that maybe use a tricky gadget to detect when the leisure battery is being charged, and feed a small trickle charge to the starter battery whenever that happens. So no need for the second mains trickle charger for the starter battery.

Another advantage of the gadget is that when the leisure batteries are being charged by solar, the gadget still works to trickle charge the starter battery.

This thread is about how the gadget detects whether the leisure battery is being charged. A lead-acid battery has a maximum resting voltage of about 12.8V. So if it's 13.0V or more, the gadget can conclude it's being charged, and start trickle charging the starter battery.

Trouble is, Lithium batteries are different, and have a different resting voltage and a different response when being charged. So a different setting is needed for lithium batteries.

Then there's the smart alternator problem. The alternator intentionally doesn't fill the starter battery, to leave spare capacity for dumping energy from the regenerative braking system. So the gadget needs to know if it's a smart alternator, so it doesn't fill the starter battery completely. That's why the gadget needs smart alternator settings.

And finally, what if the MH is stored in a barn (no hookup, no solar), the leisure battery is at 90% but the starter battery is getting flat because it's running the alarm, tracker etc. Maybe there should be a switch to manually turn on the trickle charger even if the leisure battery isn't being charged.

And it all sounded so simple to start with...

Now you have really confused him.

 

[Hoovie]

Just to hopefully help, there is a "taskforce" being engaged tomorrow to go right through the instructions and make them a lot more 'user-friendly' so a revised datasheet version in plainer English will be posted up very soon.

Also, something that has not been mentioned, but I think "wildbunch" wondered about? the need for fuses? I used to supply cables with fuseholders, but I don't do so any longer as the AMT is internally fused. And to confirm, the fuse is self-resetting

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[Hoovie]

If you had mains hookup, one way to keep both batteries charged is to have a big charger for the leisure batteries, and a separate small 'trickle' charger to keep the starter battery topped up. That would all work fine.

Then someone had the idea that maybe use a tricky gadget to detect when the leisure battery is being charged, and feed a small trickle charge to the starter battery whenever that happens. So no need for the second mains trickle charger for the starter battery.

Another advantage of the gadget is that when the leisure batteries are being charged by solar, the gadget still works to trickle charge the starter battery.

This thread is about how the gadget detects whether the leisure battery is being charged. A lead-acid battery has a maximum resting voltage of about 12.8V. So if it's 13.0V or more, the gadget can conclude it's being charged, and start trickle charging the starter battery.

Trouble is, Lithium batteries are different, and have a different resting voltage and a different response when being charged. So a different setting is needed for lithium batteries.

Then there's the smart alternator problem. The alternator intentionally doesn't fill the starter battery, to leave spare capacity for dumping energy from the regenerative braking system. So the gadget needs to know if it's a smart alternator, so it doesn't fill the starter battery completely. That's why the gadget needs smart alternator settings.

And finally, what if the MH is stored in a barn (no hookup, no solar), the leisure battery is at 90% but the starter battery is getting flat because it's running the alarm, tracker etc. Maybe there should be a switch to manually turn on the trickle charger even if the leisure battery isn't being charged.

And it all sounded so simple to start with... and it's still 2 days to the full moon

That is a very nice summary
My problem is my posts tend to waffle on too much and I am sure people go into the "TL: DR" mode

 

[WildBunch]

Hi
Thanks to Hoovie, LeneyHB & others for all the feedback. My AMT12-2 is on order & hopefully will be delivered soon.
I must confess I do not fully understand all the different settings that are possible. I am looking forward to the updated instructions.

 

[eddie]

Considering the flexibility of this device over something like the Battery Master (more expensive, but one single way of working and only with Lead) or the Votronic (cheaper but incredibly expensive for a diode and resistor in a plastic box), it is amazing value I think.
(And for those who look for this feature ... The AMT is designed and built in the UK (Salford, Manchester to be precise))

Don't normally get involved in these type of threads, but just to correct you

Jim's Shop (for Funsters) sells the Battery Master for £59.99 we haven't had a single issue with them working with Lithium (we install hundreds)

Also its three wires to connect and that's that! 100% waterproof by the way, idiot proof in that you can connect it up the wrong way around or short circuit it and it will just turn its self off, and you don't need to buy fuses as it has automatic resetting fuses internally (Part of the idiot proofing )

Why on earth something needs to be so complicated to trickle charge an engine battery over a period of weeks, and if its only days? you park up, you don't need either product.

 

[Hoovie]

Don't normally get involved in these type of threads, but just to correct you

Jim's Shop (for Funsters) sells the Battery Master for £59.99 we haven't had a single issue with them working with Lithium (we install hundreds)

Also its three wires to connect and that's that! 100% waterproof by the way, idiot proof in that you can connect it up the wrong way around or short circuit it and it will just turn its self off, and you don't need to buy fuses as it has automatic resetting fuses internally (Part of the idiot proofing )

Why on earth something needs to be so complicated to trickle charge an engine battery over a period of weeks, and if its only days? you park up, you don't need either product.

If you are looking to correct me, no worries, but I am entitled to respond ....
[Broken Link Removed] "Cash and Carry - £69.95" . So more expensive. I refer to published general public prices.
Now Jims Shop for Funsters (https://www.motorhomefun.co.uk/portal/batter-master-order-form/) .... Actually the price is £64.99 + £3.95 shipping (=£68.94) not £59.95, so even the "special" Funsters deal is no cheaper than the AMT at the standard price at wildebus.com

Lithium ... "It is designed that when the engine battery drops half a volt below the leisure battery, Battery Master automatically adjusts the charge and tops up the engine battery". So it is likely to draw power from the Lithium Battery all the time if the starter is a bit low (and especially if the vehicle is fitted with a Smart Alternator where the Starter Battery sits at a lower voltage.
That is not how I consider a Trickle Charger should operate, but If people are fine with that mode of operation, no worries. Personally, it would not be for me.

Fuse? if you read the whole thread you will see fuses are not needed for the AMT either as it also has a self-resetting fuse protection.
It is good it is 100% Waterproof though, for when someone leaves their open-topped motorhome out in rain (I think they may have bigger issues with water than a trickle-charger though )

Do you need something so complicated? Installing the AMT is no more complicated then fitting the Battery Master as it will come ready set and the user just has to connect the 3 wires. No more complex for the user but has the POTENTIAL of a great deal more.

 

[eddie]

This is why I don't get involved in these types of posts, if your happy with a product, yell it from the rooftop, why feel the need to justify its good by saying it is better than a well known tried and tested product that there are literally thousands on, tens of thousands of, being used as we talk.

Waterproof? a lot of older vans that really do need the assistance have the battery and split charger under the bonnet so being waterproof, vibration proof and dust proof is a benefit

I designed the original Battery Master to solve an issue, motorhomes are 99.9% built on delivery vans that are designed with one battery and to be used day in day out stop start Monday to Friday. The converters buy them, add fridges and freezers, extra batteries etc without changing the alternator and add a whole host of additional electrical equipment and sell them as motorhomes which we buy and love till the Weather gets cold and despite us intending to use the camper at Christmas, Aunt Flo's is ill so we suddenly realise that its March and we have a flat battery!

Our Lithium installations run into hundreds, most have a BM fitted mine included and we have experienced no issues as fundamentally you can't charge a fully charged battery, we sell them trade normally 50 or 100 units a time to dealers and converters but I would admit, with us not being a mail order business aren't really geared up for retail sales and truthfully don't want to be

I was wrong about the price anyway, your device is cheapest, but the link below supports the forum.

[Broken Link Removed]

As for potential? crack on, Van Bitz Battery Master customers just expect to be able to jump into their campers after a few weeks and know that the engine will start, which it does which is why the reviews are always so good

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[Hoovie]

It's called "choice".
sometimes a product is right for one person and not for another. (see post #6 as an example)

 

[eddie]

It's called "choice".
sometimes a product is right for one person and not for another. (see post #6 as an example)

I agree.

Re post #6 So what! Why wouldn't a Battery Master work in Mid Winter? I'm definitely not "Poo - Poo'ing" what Lenny has said (who I hold in high regard) but there would be external reasons, third party equipment complications that led someone to that belief, who then told Lenny what he believed, who in turn has now told you, and you are quoting at me, trying to prove an argument that Professionally I know doesn't exist as we are installing Battery Masters as part of £5K - £8K Lithium setups, on a virtually daily basis to solve a problem with quiescent drain on vans designed as daily delivery vans


I spoke to someone who said they knew some one who'd been gassed you know!

 

[Hoovie]

you need to chill out!

 

[Wabs]

you need to chill out!

. I think you need to chill out,, Eddie is a trusted member , and an expert in his field, I would always go with someone who knows more that me ( which is most times), I know I’d rather buy a product that was well tested and fitted by experts than rely on some flea bay product which I would have to fit my self,, no brainier really, you wouldn’t ask a Mc Donald’s flipper to pilot a plane,

 

[Hoovie]

So Eddie goes off on one "correcting" me when the only reference I made to his product was the fact it happened to be more expensive than the AMT asked about by someone else (not started by me). And then his "correction" was actually wrong anyway as it IS more expensive, as I noted, and he admitted.

I am not that bothered as I am not defending one product over another, just explaining the details of how one works. It is not MY product, although I am familiar with in, having been involved with the initial evaluation of the device prior to use and helping tweak its settings and configuration.

So yes, Eddie does needs to Chill out, thinking someone is out of order by having the temerity to discuss an product that is an alternative to something he has made, and which happens as an aside to be a lesser price and more features available as standard if wanted.

Not sure where "fleabay" is? is it a shop?

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