SELMAR BATTERY CHARGER TURBO 12

[hosin]

i have a SELMAR BATTERY CHARGER TURBO 12 it doesn't work any more after charger my car battery that i find out that is has a short circuit so i think is that what damage my battery charger :'( So i open it then i found that the Bridge Rectifier SB151 is cracked and it cause a short circuit, i search about it in internet but it looks that is not easy to find it, and i found others Bridge Rectifier that can support to 35 A, so i have tow question;
1 : what Bridge Rectifier can replace SB151 if i don't find it exactly
2 : after removing all wires, i tired remembering how this battery charger was wiring! but i can't ! I will be very thankfully i really need the wiring schema

 

[ericmark]

The old battery chargers have no real regulation and relied on the transformer and rectifier being very poor quality so charge rate would drop as battery was charged, but although they can recharge a battery from dead, where the protection on the more modern types need around 7.5 volt to be left in the battery, one must consider if it is really worth repairing?

Today we tend to want battery chargers we can put on a battery and forget, it goes through stages and auto reduces the charge rate without boiling the battery dry.

With a heat sink yes you can fit a different bridge rectifier, but as to how wired I would need to open mine up to see, and mine still works so not doing that, it is only used with completely discharged batteries, once they show 7.5 volt I swap to a fully automatic charger.

 

[Keithmac]

Older Optimate smart chargers need 2v, newer ones 0.5v to sense battery connection and start recovery.

Personally I would put that charger in the bin and buy a new one!.

We have a Sealey Supercharger 10 amp and that's a good simple bit of kit, plus an old "reclaimer" at work that pumps over 20v through the battery depending on condition and charge state. To be fair it has recovered a fair few batteries.

I have an Optimate 4 permanently on my weekend car and maintains the battery perfectly!.

 

[securespark]

I would replace it with a CTEK 3.8 or 5.0, depending on your needs.
https://www.amazon.co.uk/CTEK-MXS-3...42HAA?tag=autoexpress-21&ascsubtag=36236&th=1

 

[ericmark]

I use a Lidi battery charger, similar to CTEK but a lot cheaper, gone is the ammeter, it has a volt meter, plus a row of LED's the whole idea of these modern chargers is however to recharge a battery and maintain it ready to use, they do not fast charge. This charger

is nearly the same as what you have, and it still has a place when for example you have not closed the boot properly and now the car will not start, you want reasonable rapid recharge, 1/2 hour often enough to then start car, but the Lidi charger

has only a 3.8A output at best, a 60 Ah leisure battery is fully charged in 48 hours from completely flat without any need to top up electrolyte or disconnect, it can be left one for weeks, but instead of 1/2 hour before you can start car it will likely take 2 hours, and if it becomes disconnected it will not auto restart once power returns, you need to press the mode button. Great for my caravan battery, or the wheel chair battery, normally if the car has a flat battery I am in too much of a hurry to use such a small charger.

 

[DaveHerns]

Is one of those Aldi / Lidl intelligent chargers better to use to charge the 20A sealed battery in my booster pack then the PSU supplied? I just click the croc clips on to the charging leads.

 

[ericmark]

Since I don't know what is inside the supplied PSU can't answer, I know the mobility scooter charger was a stage charger, so maybe the original is what is required. The Lidi has 4 charging rates at 12 volt, 3.8A, 3A, 0.8A and 0.1A once it hits the 0.1A it shows battery as fully charged.

The whole idea is to charge slowly, if you charge too fast the chemical change can't keep up so water is lost, and if really fast it can buckle the plates, so if your in no hurry the slow charger is better, but the stage charger comes in many flavours.

Pulsed charging is also used, this monitors the voltage decay to adjust charge rate. The Lidi charger is called 7 stage, some of the stages I would not call stages.
1) Monitors battery (checks if leads on right way around) I would not call that a stage.
2) Delivers pulses until battery voltage hits level one.
3) 3.8 amp until voltage hits level two.
4) 3 amp until voltage hits level three.
5) 0.8 amp until voltage hits level four.
6) 0.1 amp until voltage drops to a lower level.
7) 0.8 amp until voltage hits level four.
To my mind it is 5 stage at best and since the first pulse stage is normally not activated I would call it a 4 stage charger.

The Lidi uses fixed amps and the voltage varies, most are the other way around, the voltage is steady and when the amps drop to a pre-set level the voltage drops, for a battery you can top up between 60 and 300 Ah it will normally start flat out, say 35 amp, as the volts hit 14.8 it will hold that voltage until the amps drop to around 4 amp, then it drops to float charge voltage of around 13.2 to 13.4 volt.

The problem arises where the battery is used and charged at the same time, if for example you have a boat or caravan on shore/site power if your lights are one you could use more than 4 amp so the charger will not drop the voltage as battery becomes 85% charged, often there is a timer as well, but the battery can get over charged, so solar panel and alternator inverter chargers use the pulse method. With a narrow boat with two 70A alternators feeding an inverter you can be charging the batteries at 140A, OK often 300 Ah of batteries, but at that output over charging can do a lot of damage.