to charge or not to charge

Oh, that's embarrassing - now I'm going to have to concede that the above is based to a limited extent on what I know about lead/acid battery chemistry, to a greater extent on "gut feel" (which is often wrong) - and that probably the overriding factor is what Barry (AndyRoyd) said above: "Life is too short to wring out every bit of life from a battery".

On my last van I changed both batteries at 6 years old - not because they were showing any signs of significant deterioration, but because I'd rather spend the money and be sure of power when I need it rather than facing an unexpected blackout while away on holiday.

My part-educated guess is that the route I'm taking is the lesser of two evils - but I don't know for sure.

Might be something or nothing but observation/advice would be appreciated. MH is in storage without access to EHU. Batteries are maintained by a 100w SP and not connected to the PCS. The EC51 control panel and the EC155 PCS are therefore redundant and are turned off. To my surprise the other day I noticed the LED’s on the control panel flashing and its buzzer sounding. I’m aware that the charging system I have incorporates an over voltage cut-out which turns the system power off if either battery voltage exceeds 15V (indicated by the display LED flashing]. But given the power control system is shut down and the control panel is turned off how can the ‘voltage’ warning system operate? Of course additionally, if a battery is overcharging, as indicated by the LED flashing, I will be concerned that the solar charge controller might not be monitoring correctly the level of charge going into the batteries.

interesting topic.  Mojo is one of the best i have noted on this site.with Peter 1#. I was qualified in electrical engineering with an ONC I also did the electrical course at RAF Newton.This is many many years ago.
My actual recent experience, 15 years ,is leaving vehicles for 3 or 6 months .I always disconnect the battery.Never had a problem.I use a cetek charger ,15 years old, for current vehicles that i am using. Have also left a solar panel on 365 days/year for 3 years on a motorhome with batteries connected.No problems.

Micky

From past similar threads, I think brodco is actually the best qualified on this subject here - IIRC his professional experience is in power supply design/implementation. But he's probably away or otherwise occupied at the moment.

Mel - I don't know the EC155 at all personally, but I have a suspicion (based on what happens with my EC328) that the solar panel and charger may be upsetting the main power control part of the EC155. On mine, I regularly see a glitch where the control panel starts sounding an alarm (briefly) and flashing the panel backlight, and it only seems to happen when there is a very sudden change in solar input (typical on a cloudy day where the clouds clear to sunlight very fast).

If this can happen on mine, with the controller that Sargent build in themselves then it doesn't surprise me to hear that it also happens with an external solar controller. The only thing that surprises me is that in your case it's "waking up" the controller from a powered-off state, which I've never seen on mine.

Quite what you can do about it I'm not sure. The obvious thing would be to locate and remove the input power fuses for the EC155 while it's in storage, as there is no way it can "wake up" with those removed! On the Celex that would be quite easy as both fuses are in a separate 3-way holder under the EC328, but I don't know if they are so easy to access on your van.

-mojo- wrote:Mel - I don't know the EC155 at all personally, but I have a suspicion (based on what happens with my EC328) that the solar panel and charger may be upsetting the main power control part of the EC155.

Quite what you can do about it I'm not sure. The obvious thing would be to locate and remove the input power fuses for the EC155 while it's in storage, as there is no way it can "wake up" with those removed! On the Celex that would be quite easy as both fuses are in a separate 3-way holder under the EC328, but I don't know if they are so easy to access on your van.

Thanks for Mojo for the reply.
I’m not sure myself where the input power fuses are for the EC155 PSU. I will need to have a close look for them. In the meantime your suggestion prompted me to have a look at the AS handbook. Under Control Panel Problems I found ‘display corrupt/erratic’. To rectify the problem it suggests a reboot of the EC155 PSU by removing/reinserting fuses 9 & 10, leaving a gap of 30 secs…of the 2x20A fuses for the two batteries. [claims it will also work by unplugging the multi-way connector at the control panel]. These fuses are situated in the PSU under the O/S bench seat. If I fail to find the PSU input power fuses and witness the unusual behaviour of the control panel again [LED flashing when it’s supposedly shut down] I will consider a reboot of the PSU or if this does not work further consider removing the fuses, whilst the MH is in storage.

Hi
Oh eck! handbags at dawn (again) ?   

willconquerer wrote:I do not favour constant charging. I have found just the opposite in that constant charging from either solar or mains chargers that constantly float charge batteries, creates wear and tear and slowly but surely (rapidly in some cases) depletes the capacity of lead acid batteries.

 
I have to say that my experience has been completely different. Certainly, in the companies I’ve worked for over the years it’s been standard practice to keep standby and occasional use batteries on float and I’ve rarely seen a premature failure.

 Yes, keeping the battery fully charged means keeping the acid at full strength increasing corrosion but allowing it to discharge even to a small extent leads to lead sulphate formation. That’s fine and normal for cyclic use but not good if lead sulphate is left on the plates for a long time in storage. Lead acid batteries will fail over time anyway. It’s all about maximizing the service life and if we get it right that can be many years.
 
I agree that continuous charging is bad but float charging is not continuous charging in the conventional sense. I think “float charge” is an unfortunate term “float mode” would be better. In float mode, we’re holding the battery terminals at the fully charged voltage allowing the battery to take only the current it needs to compensate for self-discharge.

If you’re getting failures on a regular basis I suspect there is some other factor at work, particularly if the battery capacity is going down quickly.

I’d be looking at all possible causes such as how many failures over what time period, the type and age of batteries, how the battery been used before being put on float, the charger performance and the temperature.

willconquerer wrote:This is exactly what Yuasa, Bosch and Varta say too. Yuasa say quite clearly on their website
(Continuous charging, even from a well-controlled charging system, will result in internal degradation of the battery. This could result in the battery not giving its predicted output when required even though the battery appears to be fully-charged). Anything other would be to defy the laws of physics !

 
On the other hand so will not charging!   Can we have a link please so that we can see the context?

Here are a couple of links from Yuasa that seem to indicate the opposite, one a general applications note and the other a datasheet for a general-purpose battery that can be used on float or cyclic with a 10 year life.

[You must be registered and logged in to see this link.]
 

willconquerer wrote:Allan at aandncaravan is a recognised expert on batteries and his website is a gold mine of useful information
[You must be registered and logged in to see this link.]

 
Perhaps so but I think “recognized experts” in the industry would be company like Cadex who have been in the business for donkey’s years, they have a wealth of experience and a number of reinvent patents They also design products for every section of industry and the military. Personally I'd make the Cadex site the first call for battery info.
 
[You must be registered and logged in to see this link.]

Now - where's that tin hat again.

Brod

Mel Battersby wrote:

-mojo- wrote:Mel - I don't know the EC155 at all personally, but I have a suspicion (based on what happens with my EC328) that the solar panel and charger may be upsetting the main power control part of the EC155.

Quite what you can do about it I'm not sure. The obvious thing would be to locate and remove the input power fuses for the EC155 while it's in storage, as there is no way it can "wake up" with those removed! On the Celex that would be quite easy as both fuses are in a separate 3-way holder under the EC328, but I don't know if they are so easy to access on your van.

Thanks for Mojo for the reply.
I’m not sure myself where the input power fuses are for the EC155 PSU. I will need to have a close look for them. In the meantime your suggestion prompted me to have a look at the AS handbook. Under Control Panel Problems I found ‘display corrupt/erratic’. To rectify the problem it suggests a reboot of the EC155 PSU by removing/reinserting fuses 9 & 10, leaving a gap of 30 secs…of the 2x20A fuses for the two batteries. [claims it will also work by unplugging the multi-way connector at the control panel]. These fuses are situated in the PSU under the O/S bench seat. If I fail to find the PSU input power fuses and witness the unusual behaviour of the control panel again [LED flashing when it’s supposedly shut down] I will consider a reboot of the PSU or if this does not work further consider removing the fuses, whilst the MH is in storage.

I was away when this was posted but now seeing it, if you have a solar panel you have to disconnect or cover it as well as removing the two fuses to initiate a reset I've always found it much easier to disconnect the control panel but I am used to handling such components.

brodco wrote:Hi
Oh eck! handbags at dawn (again) ?   

willconquerer wrote:I do not favour constant charging. I have found just the opposite in that constant charging from either solar or mains chargers that constantly float charge batteries, creates wear and tear and slowly but surely (rapidly in some cases) depletes the capacity of lead acid batteries.

 
I have to say that my experience has been completely different. Certainly, in the companies I’ve worked for over the years it’s been standard practice to keep standby and occasional use batteries on float and I’ve rarely seen a premature failure.

 Yes, keeping the battery fully charged means keeping the acid at full strength increasing corrosion but allowing it to discharge even to a small extent leads to lead sulphate formation. That’s fine and normal for cyclic use but not good if lead sulphate is left on the plates for a long time in storage. Lead acid batteries will fail over time anyway. It’s all about maximizing the service life and if we get it right that can be many years.
 
I agree that continuous charging is bad but float charging is not continuous charging in the conventional sense. I think “float charge” is an unfortunate term “float mode” would be better. In float mode, we’re holding the battery terminals at the fully charged voltage allowing the battery to take only the current it needs to compensate for self-discharge.

If you’re getting failures on a regular basis I suspect there is some other factor at work, particularly if the battery capacity is going down quickly.

I’d be looking at all possible causes such as how many failures over what time period, the type and age of batteries, how the battery been used before being put on float, the charger performance and the temperature.

willconquerer wrote:This is exactly what Yuasa, Bosch and Varta say too. Yuasa say quite clearly on their website
(Continuous charging, even from a well-controlled charging system, will result in internal degradation of the battery. This could result in the battery not giving its predicted output when required even though the battery appears to be fully-charged). Anything other would be to defy the laws of physics !

 
On the other hand so will not charging!   Can we have a link please so that we can see the context?

Here are a couple of links from Yuasa that seem to indicate the opposite, one a general applications note and the other a datasheet for a general-purpose battery that can be used on float or cyclic with a 10 year life.

[You must be registered and logged in to see this link.]
 

willconquerer wrote:Allan at aandncaravan is a recognised expert on batteries and his website is a gold mine of useful information
[You must be registered and logged in to see this link.]

 
Perhaps so but I think “recognized experts” in the industry would be company like Cadex who have been in the business for donkey’s years, they have a wealth of experience and a number of reinvent patents They also design products for every section of industry and the military. Personally I'd make the Cadex site the first call for battery info.
 
[You must be registered and logged in to see this link.]

Now - where's that tin hat again.

Brod

I'm 100% with Brod on this.