Battery and pumps

[Chelebell]

I have a two man system, and this week the battery is losing charge after about 7 or 8 jobs.

Ive had the battery tested which is working fine.

I know another issue can be the bushes have gone in the pump and draining the battery! How do i know which pump if there are 2?

 

[P4dstar]

Test the battery and make sure it’s fully charged. Run a pump for an hour and check it again, then recharge and run the other pump.

If a battery is losing power it’s usually the battery that is the problem. I have no idea how you would test that. Out of interest what did you do to test the battery is good?

 

[spruce]

I have a two man system, and this week the battery is losing charge after about 7 or 8 jobs.

Ive had the battery tested which is working fine.

I know another issue can be the bushes have gone in the pump and draining the battery! How do i know which pump if there are 2?

Sorry to ask, but how has it been tested?

A leisure battery that's lost is capacity will still show a full charge peaking at 12.8v. You can usually get an idea if the battery has lost capacity if it doesn't take as long timewise to recharge it.

Recently it was popular to test a leisure battery's capacity with a digital meter with a special performance algorithm. It may have worked with starter batteries but not leisure batteries. I'm old school and the only way we tested them was under a preset load for a set time dictated by the capacity of the battery being tested.

My gut is telling me that your battery is faulty.

 

[spruce]

Test the battery and make sure it’s fully charged. Run a pump for an hour and check it again, then recharge and run the other pump.

If a battery is losing power it’s usually the battery that is the problem. I have no idea how you would test that. Out of interest what did you do to test the battery is good?

I agree. Every time we have experienced a battery that suddenly didn't last the day under load, a replacement battery solved the problem.

Of course we are presuming that @Chelebell is actually recharging his battery with a good battery charger especially designed to charge leisure batteries.

He also needs to tell us more info regarding his auxillary battery and its capacity, age, how often he recharges it and if his vehicle has provision to charge his battery on the move (Split charge relay etc.)

If he does have supplementary recharging then does his van have regenerative braking and what 'combiner' (SCR, VSR or battery to battery charger) is he using.

 

[Ian Sheppard]

I agree with Spruce & P4dstar. It would be useful to know age and AH rating of the battery and the frequency of charging + method of charging. Two pump are are going to draw around 2 - 3 amps each per hour when run with  controller so combined draw of 4 - 6 amps per hour. This is where the battery capacity comes into play ( Amp Hour rating) a 75ah has a 75 amp capacity when fully charged.  Some batteries can be discharged up to 50% of their capacity in the above example this would be 37.5amps. The battery will need fully recharging at this point, Once you go below the maximum discharge point the lead cells in the battery can be damaged and effect the ability to hold a charge.  Two pumps drawing a combined 6 amps will use the 37.5 in a little over 6 hours.

Regularly draining a battery below 50% will shorten its life

Age of the battery also a factor as over time the battery is less able to hold a charge

Measuring volts is an indicator of the battery capacity (amps) as amps fall so does voltage in some cases once a battery falls below  12V to11.5V it has reached its recommended max discharge point. Drop be low 11V and the battery is 70% discharged.

In normal use a fully charged battery will see a small volt drop as its comes under load from the pump/s ( for example 12.8 to 12. 6) a good condition battery will then see a gradual voltage fall off over the day. However if a battery drops off suddenly this is a sign the battery is worn/not holding charge and may need replacement.

During a bench mains recharge a battery will gain about 70% of the charge in the first 4 - 5 hours then the remain 30% more slowly over a further 6 hours or so. Its a bit like filling a a glass from empty, Starting by pouring quickly then as the glass fills pouring more slowly to the top. Split relays are great for helping extend the period between bench charges but for most the batteries will still need a bench charging on occasion as this helps maintain good battery condition

 

[spruce]

I'm so pleased that the industry, willingly or unwillingly, has batteries classified in category A, B or C. This is extremely helpful for us as window cleaners. We are generally heavy battery users and this rating helps us to decide what leisure battery best suits our needs.

https://www.thencc.org.uk/Our_Schemes/ncc_verified_leisure_battery_scheme.aspx

Personally, I would stay away from Category C batteries.

 

[CHWS]

This was happening me the other week with a year old battery . Took it to get tested and said it was fine . I ended up just getting a new battery and keeping the old one for a half day