Charging battery (1 Viewer)

[Steven]

Hello this is my 1st post I was wondering if someone could help me out, I have a 85ahp leisure battery roughly how long will a 4 amp charger plugged into mains take to fully charge the battery?
Thanks
Steven

 

[scotjimland]

This will depend on

* how much charge is left in the battery
* age of battery
* what type of charger you have... ie, basic or multi-stage

As we don't know I will assume it's a basic automotive type taper charger ..

A taper charger charge rate is controlled by the battery voltage, as the battery charges it's voltage rises and the charge tapers off .. so it's not a simple calculation ..

Initially the charging rate will be around 4amps, but will eventually taper off to around 1 Amp

From my experience with basic automotive type chargers , it would take several days to charge an 85AH battery ..

The only reliable way to know when it's fully charged is to check with a hydrometer .


Draw electrolyte into the hydrometer a few times so that the float reaches the same temperature as the electrolyte. This will increase the accuracy of your readings.

Hold the hydrometer vertically so that the float is free and does not touch the inner walls of the barrel.

Hold the hydrometer so that the liquid is level in the barrel and at eye level.

When you draw the electrolyte, make sure that the hydrometer is full.

A hydrometer reading of 1.265 or greater at 80°F indicates a full charge.

1.265 100%
1.225 75%
1.190 50%
1.155 25%
1.120 0%

 

[Terry]

Hi Steven & welcome :thumb: Jim is right but if this proves too technical a simple answer is to leave it on charge for 24 hours.It may not hold a full charge and if you have not got a hydrometer your local spares shop will test it for you in the hope of a sale :thumb:
Bare in mind your 85 amp hr battery should never be more than 50 % discharged before damage can occur.In theory your 4 amp hr charger puts in 4 amps per hour = 10 hrs to take your battery up from 45 amps ( 50 % discharge ) to 85 = full,but as Jim says they taper off hence the 24 hr charge.
terry

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[Steven]

Charging

Thank you for your help it is just a cheap automatic charger I left it charging over night seems to of done the trick