GPS reboot on engine start

guido99 · July 10, 2009, 21:57:30 CET

A friend of mine is having a problem with his GPS rebooting each and every time he starts his electric start outboard motor. This is of course due to the momentary voltage drop while cranking the engine. My question is, is there something he can install on the power input leads of the gps to minimise the voltage drop like a capacitor or filter of some sort ?
He is looking for a temporary solution right now, next season he will have a seperate house and starting battery hooked up to a BEP Marine Voltage Sensitive Relay.

skip · July 11, 2009, 08:24:21 CET

My advice would be to start up BEFORE powering up the electronics thereby preventing the rebooting from voltage drop.

I would also be inclined to say that either a) his existing battery is on it's way out, not charging properly from the alternator because of its health, therefore needs replacing or b) the Cold Cranking Amps of the battery is not sufficient for his engine starter.

However I'm more inclined to say he needs to replace his battery asap.

Once he starts he is effectively running his electronics off the alternator.

Moonwalker · July 11, 2009, 09:54:44 CET

Sometimes this happens to me too. I guess with big motors this is normal. I dont bother much since I keep motor on all day.

A solution would be to put a diode in the positive supply wire and a capacitor from the diode to the negative supply wire. The diode should be double the current that the unit takes (which is normally 1-2A) and the capacitor you have to try on the spot since it depends how long the engine takes to start up. You should start with 10,000uF 25V and if its not enough add another one in parallel.

mellieha · July 11, 2009, 11:41:46 CET

Guys I had a similar problem.

I solved mine by utilising a bigger amperage battery. But not all situations are the same.

Please note that a battery has to be mantained well. What do I mean. It must be kept at its ideal charge. i.e. do not expect that after a winter of non usage it ill still have the same amperage. (cranking capacity) Some argue Imma kont adni kif xtrajta qabel is sajf. This is no excuse.

I will just add : Do you winterise your Motor? A simple process but very much needed.

How many winterise their batteries? You may ask but how is this done. Quite simple make sure all non sealed batteries have sufficient distilled water and to utilise a TRICKLE CHARGER. The use of a Trickle Charger is to replace slowly what the battery is loosing in terms of amps. In this way the battery is always ready to go, and one manages to benefit from all its life span.

Adrian

benri · July 11, 2009, 12:44:42 CET

what trickle charger do you use please? Where can I get one from? Also, how often do you charge please?

Destination Sea · July 11, 2009, 20:06:45 CET

Berni I use this method and worked fine for these last 7 years. Last battery lasted 5 years.... When laying up i charge the battery full. Than every two months i charge (Low charge) the battery for four hours. Than before starting to use the battery again i give it a full charge. for sealed battery trickle charge only .

guido99 · July 11, 2009, 21:25:16 CET

Gents, thank you all for the helpful advice. Like i said earlier he is only looking for a temporary fix, and therefore Moonwalker's suggestion sounds like the best solution. I'll try and get the capacitor and diode on Monday.
Anyone know where i can get these components locally ?

Destination Sea · July 11, 2009, 23:47:04 CET

There is a shop at ta Paris B Kara and Hamrun who sell electronices.
Hamrun if not mistaken is Map electronics near san frangisk church.
Ta paris is appx when going from the B Kara bypass to mater dei pass on to the street where there was the supermarket which closed price club keep going straight (parallet to mater dei road than if not mistaken 2nd corner left. you can ask their for the shop. Forgot its name and a bit difficult to explain exact directions but in that area.

skip · July 12, 2009, 11:24:41 CET

The one off the bypass in B'Kara is GE Electronics just past the camping shop but going towards Bkara but stay in the main road and as you pass the bus stop and lotto booth turn left, it's just there.

benri · July 12, 2009, 12:06:59 CET

Thanks all. I know where G&E is... I live round the corner!

venere · July 18, 2009, 17:14:46 CET

Moonwalker,
This morning i fixed what you suggested last week re GPS reboot on engine start. A capacitor of 10,000uF 25V and a diode as you mentioned solved my problem once and for all, thanks to you. As soon as i finished the installation i start up my engine (Evinrude 115 E-Tec) with my GPS (Raymarine A70 ) on and it didn't reboot.

You had solved me a big problem that i had in my mind about it cause it was stressing me that when i had to start up engine it reboots every time. Once again thanks to you i have solved a problem. Now i have to solve another problem on my Raymarine SPX-5 Autopilot, but there was a recall from Raymarine about it, hope they will resend it now.

Venere.

venere · July 18, 2009, 17:18:24 CET

By the way gents, a big thanks as well goes to Gwido99 cause he was the one who start up this topic and Moonwalker had solved this problem in seconds.

skip · July 18, 2009, 18:41:06 CET

I would still get the battery checked, you don't want to be masking the problem with the diode solution and then things get worse. better to be safe than sorry

Moonwalker · July 18, 2009, 18:45:26 CET

No problem venere - thats why I went to school to solve problems

venere · July 18, 2009, 18:59:27 CET

Skip iv checked my battery although its new and it results in an excellent condition. It's common when starting big engines due to a qualified engineer. Next season will have a separate house battery for instruments a and starting battery, both hooked up to a BEP Marine Voltage Sensitive Relay.