The Electricians last word

[Clutha]

As I’m leaving garage where he’d fitted replacement control unit for 240/12v system.

DON’T EVER PUT A BATTERY CHARGER ON A LEISURE BATTERY!

It’s a long sad saga so I’m sparing you the details.

 

For Glasgow area owners the business is Prolek in Springburn & I’d recommend them 100%.

Luckily for me my neighbours son had worked for them on van conversions & said they were very good.

[Rojie]

On 8/1/2025 at 10:26 AM, Clutha said:

As I’m leaving garage where he’d fitted replacement control unit for 240/12v system.

DON’T EVER PUT A BATTERY CHARGER ON A LEISURE BATTERY!

It’s a long sad saga so I’m sparing you the details.

 

For Glasgow area owners the business is Prolek in Springburn & I’d recommend them 100%.

Luckily for me my neighbours son had worked for them on van conversions & said they were very good.

 

Hello Gordon,

 

This assertion deserves an explanation; do you have one.

 

Are you referring to smart changers as well, or just the simple battery chargers.

 

Does your EHU use a split changer or  a VSR ?

[Clutha]

I was at the garage getting a new Sargent EC155 power unit fitted.

The original had overheated & melted a multi connector + cable while trying to charge the leisure battery via van 13amp socket & mains hookup with a bog standard 12v (maybe Halfords) charger.

(More to follow, tea’s out!)

 

Edited yesterday at 05:48 PM by Clutha
Clarity

[Clutha]

7 hours ago, Rojie said:

 

Hello Gordon,

 

This assertion deserves an explanation; do you have one.

 

Are you referring to smart changers as well, or just the simple battery chargers.

 

Does your EHU use a slit changer or  a VSR ?

 

[Clutha]

Due to leisure battery not achieving max charge while on campsite hook up or after long runs.

 I tried the charger via control unit 13amp outlet while hooked  up to domestic supply.

Almost instant smoke issued from Sargent unit.

I took van to garage referred to & their opinion was Sargent unit may have had internal component issue.
All wiring was checked out & no issues found, new Sargent ordered, fitted & all seems well.

I had replaced leisure battery too. I’ll relay its charging instructions asap.

I’m alerting members to electricians advice as the garage specialise in campervan repairs & maintenance.

I was not aware of the major differences re starting & leisure batteries.

[smurf]

So far as charging goes, a lead acid leisure battery and a lead acid starter battery require absolutely no difference in how they are charged. The differences between the construction of the batteries is minimal. If the leisure is something like an AGM battery then a charger capable of charging that battery in the correct manner should be used, but even a charger just made for a common starter battery would not make wreck an AGM battery on one charge cycle

 

It is more likely that your charger killed the Sargent unit by forcing current into its outlet side, or it was on its last legs and the charger exposed the weak point. 

[Rojie]

13 hours ago, smurf said:

So far as charging goes, a lead acid leisure battery and a lead acid starter battery require absolutely no difference in how they are charged. The differences between the construction of the batteries is minimal. If the leisure is something like an AGM battery then a charger capable of charging that battery in the correct manner should be used, but even a charger just made for a common starter battery would not make wreck an AGM battery on one charge cycle

 

It is more likely that your charger killed the Sargent unit by forcing current into its outlet side, or it was on its last legs and the charger exposed the weak point. 

 

Yes, I would agree with this likelihood. Back-charging any device can be very risky.

The output impedance/resistance can be, and should be, low; therefore current can flow in an unintended direction.

Hence my question about split charger or VSR.

[Clutha]

 

Suffice to say imho the best advice is in your leisure battery instructions.

Having purchased a special charger for my motorbikes (gel batteries) many years ago due to working offshore, & had no issues, I’ll look into its suitability for van.

Lead acid appears to be getting superseded.

Prior to my ‘incident ’ I happened to be returning to the van at a Halfords & two of their staff were checking an engine battery for someone, they checked mine too, engine battery good, leisure battery less so, thus my attempt to boost it.

Lesson learned 🙄